Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Pacific Islands Fisheries Science Center Fisheries Research

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 219

[Docket No. 210301-0032]

RIN 0648-BG31

Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Pacific Islands Fisheries Science Center Fisheries Research

AGENCY:

National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.

ACTION:

Proposed rule; request for comments.

SUMMARY:

NMFS's Office of Protected Resources (OPR) has received a request from NMFS's Pacific Islands Fisheries Science Center (PIFSC) for a Letter of Authorization (LOA) to take marine mammals incidental to fisheries research conducted in multiple specified geographical regions, over the course of five years from the date of issuance. As required by the Marine Mammal Protection Act (MMPA), NMFS is proposing regulations to govern that take, and requests comments on the proposed regulations. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorization and agency responses will be summarized in the final notice of our decision.

DATES:

Comments and information must be received no later than April 21, 2021.

ADDRESSES:

You may submit comments on this document, identified by NOAA-NMFS-2021-0026, by the following method:

• Electronic submission: Submit all public comments via the Federal e-Rulemaking Portal. Go to

www.regulations.gov

and enter NOAA-NMFS-2021-0026 in the Search box. Click on the “Comment” icon, complete the required fields, and enter or attach your comments.

Instructions:

Comments sent by any other method, to any other address or individual, or received after the end of the comment period, may not be considered by NMFS. All comments received are a part of the public record and will generally be posted for public viewing on

www.regulations.gov

without change. All personal identifying information (

e.g.,

name, address), confidential business information, or otherwise sensitive information submitted voluntarily by the sender will be publicly accessible. NMFS will accept anonymous comments (enter “N/A” in the required fields if you wish to remain anonymous). Attachments to electronic comments will be accepted in Microsoft Word, Excel, or Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT:

Amy Fowler, Office of Protected Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Availability

A copy of PIFSC's application and any supporting documents, as well as a list of the references cited in this document, may be obtained online at:

www.fisheries.noaa.gov/action/incidental-take-authorization-noaa-fisheries-pifsc-fisheries-and-ecosystem-research.

In case of problems accessing these documents, please call the contact listed above (see

FOR FURTHER INFORMATION CONTACT

).

Purpose and Need for Regulatory Action

This proposed rule would establish a framework under the authority of the MMPA (16 U.S.C. 1361

et seq.

) to allow for the authorization of take of marine mammals incidental to the PIFSC's fisheries research activities in the Hawaiian Archipelago, Mariana Archipelago, American Samoa Archipelago, and Western and Central Pacific Ocean.

We received an application from the PIFSC requesting five-year regulations and LOA to take multiple species of marine mammals. Take would occur by Level B harassment incidental to the use of active acoustic devices, as well as by visual disturbance of pinnipeds, and by Level A harassment, serious injury, or mortality incidental to the use of fisheries research gear. Please see “Background” below for definitions of harassment.

Legal Authority for the Proposed Action

Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs the Secretary of Commerce to allow, upon request, the incidental, but not intentional taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region for up to five years if, after notice and public comment, the agency makes certain findings and issues regulations that set forth permissible methods of taking pursuant to that activity and other means of effecting the “least practicable adverse impact” on the affected species or stocks and their habitat (see the discussion below in the “Proposed Mitigation” section), as well as monitoring and reporting requirements. Section 101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR part 216, subpart I provide the legal basis for issuing this proposed rule containing five-year regulations, and for any subsequent LOAs. As directed by this legal authority, this proposed rule contains mitigation, monitoring, and reporting requirements.

Summary of Major Provisions Within the Proposed Rule

Following is a summary of the major provisions of this proposed rule regarding PIFSC fisheries research activities. These measures include:

• Monitor the sampling areas to detect the presence of marine mammals before and during deployment of certain research gear;

• Delay setting or haul in gear if marine mammal interaction may occur;

• Haul gear immediately if marine mammals may interact with gear; and

• Required implementation of the mitigation strategy known as the “move-on rule mitigation protocol” which incorporates best professional judgment, when necessary during certain research fishing operations.

Background

Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1361

et seq.

) directs the Secretary of Commerce (as delegated to NMFS) to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made, regulations are issued, and notice is provided to the public.

An authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s), will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses (where relevant), and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring and reporting of such takings are set forth.

NMFS has defined “negligible impact” in 50 CFR 216.103 as an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival.

The MMPA states that the term “take” means to harass, hunt, capture, kill or attempt to harass, hunt, capture, or kill any marine mammal.

Except with respect to certain activities not pertinent here, the MMPA defines “harassment” as: Any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild (Level A harassment); or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering (Level B harassment).

National Environmental Policy Act

To comply with the National Environmental Policy Act of 1969 (NEPA; 42 U.S.C. 4321

et seq.

) and NOAA Administrative Order (NAO) 216-6A, NMFS must evaluate our proposed action (

i.e.,

the promulgation of regulations and subsequent issuance of incidental take authorization) and alternatives with respect to potential impacts on the human environment.

Accordingly, NMFS has prepared a draft Environmental Assessment (EA;

Draft Programmatic Environmental Assessment for Fisheries and Ecosystem Research Conducted and Funded by the Pacific Islands Fisheries Science Center

) to consider the environmental impacts associated with the PIFSC's proposed activities as well as the issuance of the regulations and subsequent incidental take authorization. A notice of availability of a Draft Programmatic EA and request for comments was published in the

Federal Register

on December 4, 2015 (80 FR 75856). The draft EA is posted online at:

www.fisheries.noaa.gov/action/incidental-take-authorization-noaa-fisheries-pifsc-fisheries-and-ecosystem-research.

Information in the EA, PIFSC's application, and this document collectively provide the environmental information related to proposed issuance of these regulations and subsequent incidental take authorization for public review and comment. We will review all comments submitted in response to this document prior to concluding our NEPA process or making a final decision on the request for incidental take authorization.

Summary of Request

On November 30, 2015, we received an adequate and complete application from PIFSC requesting authorization to take small numbers of marine mammals incidental to fisheries research activities. On December 7, 2015 (80 FR 75997), we published a notice of receipt of PIFSC's application in the

Federal Register

, requesting comments and information related to the PIFSC request for thirty days. We received comments jointly from The Humane Society of the United States and Whale and Dolphin Conservation (HSUS/WDC). These comments were considered in development of this proposed rule and are available online at:

www.fisheries.noaa.gov/action/incidental-take-authorization-noaa-fisheries-pifsc-fisheries-and-ecosystem-research.

While it has been multiple years since the PIFSC's application was received, the description of the activity remains accurate. Further, science and information necessary to evaluate this request that has become available since the PIFSC submitted their application has been considered and is addressed in this proposed rule.

PIFSC proposes to conduct fisheries research using trawl gear used at various levels in the water column, hook-and-line gear (including longlines with multiple hooks, bottomfishing, and trolling), and deployed instruments (including various traps). If a marine mammal interacts with gear deployed by PIFSC, the outcome could potentially be Level A harassment, serious injury (

i.e.,

any injury that will likely result in mortality), or mortality. Although any given gear interaction could result in an outcome less severe than mortality or serious injury, we do not have sufficient information to allow parsing these potential outcomes. Therefore, PIFSC presents a pooled estimate of the number of potential incidents of gear interaction and, for analytical purposes we assume that gear interactions would result in serious injury or mortality. PIFSC also uses various active acoustic while conducting fisheries research, and use of some of these devices has the potential to result in Level B harassment of marine mammals. Level B harassment of pinnipeds hauled out may also occur, as a result of visual disturbance from vessels conducting PIFSC research.

PIFSC requests authorization to take individuals of 15 species by Level A harassment, serious injury, or mortality (hereafter referred to as M/SI) and of 25 species by Level B harassment. The proposed regulations would be valid for five years from the date of issuance.

Description of the Specified Activity

Overview

The Federal Government has a responsibility to conserve and protect living marine resources in U.S. waters and has also entered into a number of international agreements and treaties related to the management of living marine resources in international waters outside the United States. NOAA has the primary responsibility for managing marine finfish and shellfish species and their habitats, with that responsibility delegated within NOAA to NMFS.

In order to direct and coordinate the collection of scientific information needed to make informed fishery management decisions, Congress created six regional fisheries science centers, each a distinct organizational entity and the scientific focal point within NMFS for region-based Federal fisheries-related research. This research is aimed at monitoring fish stock recruitment, abundance, survival and biological rates, geographic distribution of species and stocks, ecosystem process changes, and marine ecological research. The PIFSC is the research arm of NMFS in the Pacific Islands region of the United States. The PIFSC conducts research and provides scientific advice to manage fisheries and conserve protected species in the geographic research area described below and provides scientific information to support the Western Pacific Fishery Management Council and other domestic and international fisheries management organizations.

The PIFSC collects a wide array of information necessary to evaluate the status of exploited fishery resources and the marine environment. PIFSC scientists conduct fishery-independent research onboard NOAA-owned and operated vessels or on chartered vessels. Such research may also be conducted by cooperating scientists on non-NOAA vessels when the PIFSC helps fund the research. The PIFSC proposes to administer and conduct approximately 19 survey programs over the five-year period, within four separate research areas (some survey programs are conducted across more than one research area; see Table 1-1 in PIFSC's application). The gear types used fall into several categories: Towed trawl nets fished at various levels in the water column, hook-and-line gear (including longline gear), traps, and other instruments. Only use of trawl nets, longlines, and deployed instruments and traps are likely to result in interaction with marine mammals via entanglement. Many of these surveys also use active acoustic devices that may result in Level B harassment.

Dates and Duration

The specified activity may occur at any time during the five-year period of validity of the proposed regulations. Dates and duration of individual surveys are inherently uncertain, based on congressional funding levels for the PIFSC, weather conditions, or ship contingencies. In addition, cooperative

research is designed to provide flexibility on a yearly basis in order to address issues as they arise. Some cooperative research projects last multiple years or may continue with modifications. Other projects only last one year and are not continued. Most cooperative research projects go through an annual competitive selection process to determine which projects should be funded based on proposals developed by many independent researchers and fishing industry participants. PIFSC survey activity occurs during most months of the year. Trawl surveys occur primarily during May through June and September but may occur during any month, and hook-and-line surveys generally occur during fall.

Specified Geographical Region

The PIFSC conducts research in the Pacific Islands within four research areas: The Hawaiian Archipelago Research Area (HARA), the Mariana Archipelago Research Area (MARA), the American Samoa Archipelago Research Area (ASARA), and the Western and Central Pacific Research Area (WCPRA). The first three research areas are considered to extend approximately 24 nautical miles (nmi; 44.5 kilometers (km)) from the baseline of the respective archipelagos (

i.e.,

approximately the outer limit of the contiguous zone). The WCPRA is considered to include the remainder of archipelagic U.S. Exclusive Economic Zone (EEZ) waters, the high seas between the archipelagic U.S. EEZ waters, and waters around the Pacific remote islands. Please see Figures 1.2 and 2.1 through 2.4 in the PIFSC application for maps of the four research areas. We note here that, while the specified geographical regions within which the PIFSC operates may extend outside of the U.S. EEZ, the NMFS' authority under the MMPA does not extend into foreign territorial waters. For further information about the specified geographical regions, please see the descriptions found in Sherman and Hempel (2009) and Wilkinson

et al.

(2009).

In general, the Pacific region encompassing the PIFSC research areas is a complex oceanographic system. The equatorial area has relatively steady weather patterns and surface currents, but these can change based on ocean-atmospheric conditions. The El Niño-Southern Oscillation (ENSO) largely drives the climate in the tropical Pacific (Wood

et al.,

2006), with warm El Niño or cold La Niña phases, occurring every 2-7 years, impacting equatorial upwelling and ecological systems (Barber, 1988; Glynn and Ault, 2000). ENSO results in the reduction of trade winds, which reduces the intensity of the westward flowing equatorial surface current. When this occurs, the eastward-flowing countercurrent dominates oceanic circulation and brings warm, low-nutrient waters to eastern margins of the Pacific, which in turn can influence marine mammal presence. Trade winds play a vital role in dictating sea level, thermal conditions, and nutrient distribution (Wytki and Meyers, 1976).

Habitat throughout the four specified geographical regions include seamounts, atolls, reef habitat, and pelagic waters. Oceanic islands generally lack an extensive shelf area of relatively shallow water extending beyond the shoreline. Instead, most often have a deep reef slope, angled between 45 and 90 degrees toward the ocean floor. Species compositions along deep reef slopes, banks, and seamounts all can vary widely based on depth, light, temperature, and substrate.

HARA

—The Hawaiian Archipelago is one of the most geographically isolated island systems in the world, stretching over 2,450 km and consisting of eight main volcanic oceanic islands, 124 smaller islands, atolls, banks, and numerous seamounts. The region is considered part of the Insular Pacific-Hawaiian Large Marine Ecosystem (LME). Due to its isolation, the region is characterized overall by relatively low faunal diversity but unusually high endemism. The region is divided into the inhabited Main Hawaiian Islands (the eight high volcanic islands), where many watersheds and nearshore areas have been significantly modified, and the uninhabited Northwestern Hawaiian Islands (NWHI), with some of the most pristine coral reefs in the world. The archipelago is formed by the northwest movement of the Pacific plate over a stationary “hotspot.” The main islands are younger, higher, and more volcanically active, while the NWHI have largely undergone submergence and exist as coral atolls, small sand islands, and submerged banks stretching to Kure Atoll, the northernmost atoll in the world. The major oceanographic influence on the region is the North Equatorial Current, which branches along the Hawaiian Ridge into a North Hawaiian Ridge Current and gyres in the lee of the islands. The region is also seasonally influenced by the Subtropical Front (STF), which corresponds to a shallow subtropical countercurrent that transects the LME in winter and summer (Kobashi

et al.,

2006). The region has relatively consistent and tropical meteorological and oceanographic conditions, with average sea surface temperatures (SST) of 23-24°C, and is considered to be of low productivity. The region is subject to high wave energy produced from weather systems generated off the Aleutian Islands and other areas of the North Pacific, which can have major effects on nearshore habitat.

MARA

—The Mariana Archipelago, which is approximately 4,115 km west-southwest of Hawaii, includes volcanic and raised limestone islands and submerged banks stretching 825 km from Guam Island north to Farallon de Pajaros (which is about 550 km south of Iwo Jima). The region is divided politically into the Commonwealth of the Northern Mariana Islands and the Territory of Guam. The archipelago is flanked by the Mariana Trench, which include the deepest water on Earth (11,034 m) in its southern end near Guam. The archipelago, as well as a chain of submerged seamounts located approximately 120 nmi west of the Mariana Islands, and the trench were formed approximately 43 million years ago by the subduction of the Pacific tectonic plate under the Philippine plate. Geological faulting of large areas in the older southern portion of the region has created large, oblique shallow-water surfaces that have supported extensive reef growth and the development of reef flats and lagoons over time. In contrast, the islands in the north are younger with more vertical profiles that do not provide the basis for extensive reef development. As a result, this spectrum of physical conditions creates a suite of different habitats that in turn support a variety of biological communities. The primary surface current affecting the region is the North Equatorial Current, which flows westward through the islands; however, the Subtropical Counter Current also influences the Northern Mariana Islands and generally flows in a easterly direction. SST ranges from approximately 27-29°C.

ASARA

—The American portion of the Samoan Archipelago, approximately 14° south of the equator, includes five volcanic islands and two remote atolls within the U.S. EEZ (the broader Samoan Archipelago also includes islands in the independent country of Samoa and the French protectorate of Wallis and Futuna). The largest island, Tutuila, is nearly bisected by Pago Pago Harbor, the deepest and one of the most sheltered embayments in the South Pacific. The primary surface current affecting the region is the Equatorial Current, which flows westward through the islands. The region experiences southeast trade winds that result in frequent rains and a warm tropical climate.

WCPRA

—In addition to EEZ waters beyond the contiguous zones of the regions described above, the WCPRA also includes the high seas and the Pacific Remote Islands Area, comprised of Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Wake Atoll, and Palmyra Atoll. Palmyra Atoll, Kingman Reef, and Baker, Howland, and Jarvis Islands are all part of the U.S. Fish and Wildlife Service's National Wildlife Refuge System.

Howland and Baker Islands are uninhabited U.S. possessions in the Phoenix Island Archipelago. Baker Island is located approximately 21 km north of the equator and approximately 2,963 km to the southwest of Honolulu. It is a coral-topped seamount surrounded by a narrow fringing reef that drops steeply close to shore.

Jarvis Island, a relatively flat, sandy coral island, is approximately 2,092 km south of Honolulu and 1,609 km east of Baker Island. Although the westward-flowing South Equatorial Current is the primary surface current, the eastward-flowing Equatorial Undercurrent drives strong, topographically influenced equatorial upwelling in these islands. However, species diversity is much lower than in the Northern Line Islands, reflecting the influence of primary currents that originate in the species-poor eastern Pacific. Jarvis Island is considered part of the Southern Line Islands, but is biogeographically more similar to Baker and Howland Islands as its primary influence is the South Equatorial Current.

Johnston Atoll lies approximately 800 km south of French Frigate Shoals in the NWHI. Johnston Atoll, a coral reef and lagoon complex on a relatively flat, shallow platform, shares biogeographic affinities with the Hawaiian Archipelago, with evidence of larval transport between the two. Because of faunal affinities and because both occur in the oceanic North Pacific Transition Zone Province (Longhurst, 1998), the two areas may be considered part of the same ecoregion. Johnston Atoll has been used for military purposes since World War II.

Kingman Reef consists of a series of fringing reefs around a central lagoon that does not have any emergent land to support vegetation.

Wake Atoll, comprised of three different islets, is located about 3,380 km west of Hawaii, at the northern end of the Marshall Islands archipelago in the North Pacific Tropical Gyre Province (Longhurst, 1998). Wake Atoll has primarily been used for military and emergency aviation purposes since World War II.

Palmyra Atoll (1,956 km south of Honolulu) and Kingman Reef (61 km northwest of Palmyra) are part of the Northern Line Islands (other islands in this archipelago belong to the Republic of Kiribati), and are sporadically influenced by the North Equatorial Countercurrent, which flows from high biodiversity regions of the western Pacific. Palmyra Atoll consists of 52 islets surrounding three central lagoons.

Detailed Description of Activities

The Federal Government has a trust responsibility to protect living marine resources in waters of the United States. These waters extend to 200 nmi from the shoreline and include the EEZ. The U.S. government has also entered into a number of international agreements and treaties related to the management of living marine resources in international waters outside of the EEZ (

i.e.,

the high seas). To carry out its responsibilities over U.S. and international waters, Congress has enacted several statutes authorizing certain Federal agencies to administer programs to manage and protect living marine resources. Among these Federal agencies, NOAA has the primary responsibility for protecting marine finfish and shellfish species and their habitats. Within NOAA, NMFS has been delegated primary responsibility for the science-based management, conservation, and protection of living marine resources under statutes including the Magnuson-Stevens Fishery Management Act (MSA), MMPA, and the Endangered Species Act (ESA).

Within NMFS, six regional fisheries science centers direct and coordinate the collection of scientific information needed to inform fisheries management decisions. Each science center is a distinct entity and is the scientific focal point for a particular region. PIFSC conducts research and provides scientific advice to manage fisheries and conserve protected species in the Pacific Islands. PIFSC provides scientific information to support the Western Pacific Fishery Management Council and other domestic and international fisheries management organizations.

The PIFSC collects a wide array of information necessary to evaluate the status of exploited fishery resources and the marine environment. PIFSC scientists conduct fishery-independent research onboard NOAA-owned and operated vessels or on chartered vessels, and some PIFSC-funded research is conducted by cooperative scientists. The PIFSC proposes to administer and conduct approximately 19 survey programs over the five-year period (see Table 1.1 in PIFSC's application).

Given the vast geographic scope of the PIFSC region of responsibility, not all areas will be visited each year (nor will all surveys be conducted each year) within the five-year period the proposed regulations and LOA would be effective. Instead, surveys will rotate depending on funding, random sampling design, or immediate research needs. Research surveys are generally focused on one research area every year and that research area is visited every second, third, or fourth year. For example, over the course of five years, this research cycle might be presented as HARA→ASARA→MARA→WCPRA→HARA. This cycle inherently includes some overlap of any one research area (

e.g.,

Wake Atoll in the WCPRA is usually visited when the ship is transiting to MARA because it is on the way and makes for the most cost-efficient model). Furthermore, a specific survey may be prioritized every year, for several years in a row, in one research area because of a defined management need. In general, each research area coverage depends on funding, ship logistics, weather systems, research priorities, and geographic coverage during ship transit. Research is conducted more frequently in the HARA due to PIFSC's physical location in the main Hawaiian Islands.

The fishing gear types used by PIFSC fall into several categories: towed nets fished at various levels in the water column, hook-and-line gear, and traps. The PIFSC also deploys a variety of moored instruments. The use of trawl nets and longlines is likely to result in interaction with marine mammals. In addition, the PIFSC anticipates that its deployment of instruments and traps may result in the entanglement of some animals. Many of the proposed surveys also use active acoustic devices that may result in Level B harassment.

Surveys may be conducted aboard NOAA-operated research vessels (R/V), including the

Oscar Elton Sette

and

Okeanos Explorer,

as well as the University of Hawai'i research vessel

Ka'imikai-o-Kanoloa

(KoK) and assorted other small vessels owned by PIFSC. Surveys could also be conducted aboard vessels owned and operated by cooperating agencies and institutions, or aboard charter vessels.

In the following discussion, we summarily describe various gear types used by PIFSC, with reference to specific fisheries and ecosystem research activities conducted by the PIFSC. This is not an exhaustive list of gear and/or devices that may be utilized by PIFSC but is representative of gear categories and is complete with regard to all gears with potential for interaction

with marine mammals. Additionally, relevant active acoustic devices, which are commonly used in PIFSC survey activities, are described separately in a subsequent section. Please see Appendix A of PIFSC's application for further description, pictures, and diagrams of research gear and vessels. Full details regarding planned research activities are provided in Table 1.1 of PIFSC's application, with specific gear used in association with each research project and full detail regarding gear characteristics and usage provided. A summary of PIFSC's proposed research programs that may result in take from interaction with fishing gear is provided below (Table 1).

Trawl nets

—A trawl is a funnel-shaped net towed behind a boat to capture fish. The codend (or bag) is the fine-meshed portion of the net most distant from the towing vessel where fish and other organisms larger than the mesh size are retained. In contrast to commercial fishery operations, which generally use larger mesh to capture marketable fish, research trawls often use smaller mesh to enable estimates of the size and age distributions of fish in a particular area. The body of a trawl net is generally constructed of relatively coarse mesh that functions to gather schooling fish so that they can be collected in the codend. The opening of the net, called the mouth, is extended horizontally by large panels of wide mesh called wings. The mouth of the net is held open by hydrodynamic force exerted on the trawl doors attached to the wings of the net. As the net is towed through the water, the force of the water spreads the trawl doors horizontally apart. The top of a net is called the headrope, and the bottom is called the footrope. Bottom trawls may use bobbins or roller gear to protect the footrope as the net is dragged along the seabed.

The trawl net is usually deployed over the stern of the vessel and attached with two cables (or warps) to winches on the deck of the vessel. The cables are played out until the net reaches the fishing depth. Trawl vessels typically travel at speeds of 2-5 knots (kt) while towing the net for time periods up to several hours. The duration of the tow depends on the purpose of the trawl, the catch rate, and the target species. At the end of the tow the net is retrieved and the contents of the codend are emptied onto the deck. For research purposes, the speed and duration of the tow and the characteristics of the net are typically standardized to allow meaningful comparisons of data collected at different times and locations. Active acoustic devices (described later) incorporated into the research vessel and the trawl gear monitor the position and status of the net, speed of the tow, and other variables important to the research design.

PIFSC research trawling activities utilize pelagic (or midwater) and surface trawls, which are designed to operate at various depths within the water column but not to contact the seafloor. Commercial midwater trawls may be 75-136 m in width with opening height of 10-20 m; however, PIFSC uses smaller research trawls. These include a modified Cobb midwater trawl, the Isaacs-Kidd (IK) trawl, and various other small-mesh nets used as surface trawls. The Cobb trawl is generally used to target snapper and grouper species within the 0-250 m depth range, and has a mouth opening of 686 m

2

. The IK trawl is used to collect midwater or surface biological specimens larger than those taken by standard plankton nets. The PIFSC uses two sizes of IK trawls for various research purposes, a 6-ft (1.8-m) wide model and a 10-ft (3.0-m) wide model. These nets may be towed either at the surface of the water or at various midwater depths depending on research protocols or where acoustic signals indicate the presence of study organisms. Tow durations are typically 30-60 min for small-mesh surface tows, 60 min for IK surface tows, or 60-240 min for midwater tows, with midwater tow depths varied during a tow to target fish at different water depths. PIFSC trawls are typically towed at 2.5-3.5 kt.

Longline

—Longline vessels fish with baited hooks attached to a mainline. The length of the longline and the number of hooks depend on the species targeted, the size of the vessel, and the purpose of the fishing activity. Pelagic longlines, which fish near the surface with the use of floats, may be deployed in such a way as to fish at different depths in the water column. For example, deep-set longlines targeting tuna may have target depths greater than 100 m, while a shallow-set longline targeting swordfish is set at depths shallower than 100 m (see Figure A-7 of PIFSC's application). Hooks are attached to the mainline by another thinner line called a gangion or branch line. The length of the gangion and the distance between gangions depends on the purpose of the fishing activity. PIFSC uses pelagic longline gear, which is deployed near the surface of the water, with buoys attached to the mainline to provide flotation and keep the baited hooks suspended in the water. Radar reflectors, radio transmitters, and light sources are often used to help fishers determine the location of the longline gear prior to retrieval.

A commercial longline can be miles long and have thousands of hooks attached. Although longlines used for research surveys are often shorter, the PIFSC uses some commercial-scale longlines,

i.e.,

600 to 2,000 hooks attached to a mainline up to 60 miles in length. There are no internationally-recognized standard measurements for hook size, and a given size may be inconsistent between manufacturers. Larger hooks, as are used in longlining, are referenced by increasing whole numbers followed by a slash and a zero as size increases (

e.g.,

1/0

up to 20/0). The numbers represent relative sizes, normally associated with the gap (the distance from the point tip to the shank).

The time period between deployment and retrieval of the longline gear is the soak time. Soak time is an important parameter for calculating fishing effort. For commercial fisheries the goal is to optimize the soak time in order to maximize catch of the target species while minimizing the bycatch rate and minimizing damage to target species that may result from predation by sharks or other predators. PIFSC pelagic longline soak times range from 600-1,800 min.

Other hook and line gear

—Hook and line is a general term used for a range of fishing methods that employ short fishing lines with hooks in one form or another (as opposed to longlines). This gear is similar to methods commonly used by recreational fishers and may generally include handlines, hand reels, powered reels, rod/pole and line, drop lines, and troll lines, all using bait or lures in various ways to attract target species. The gear used in PIFSC bottomfish surveys consists of a main line with a 2-4 kg weight attached to the end. Several 40-60 cm sidelines with circle hooks are attached above the weight at 0.5-1 m intervals. A chum bag containing chopped fish or squid may be suspended above the highest of these hooks. Dead fish and bait would not be discarded from the vessel while actively fishing and would only be discarded after gear is retrieved and immediately before the vessel leaves the sampling location for a new area. The gear is retrieved using hydraulic or electric reels after several fish are hooked. Another hook-and-line fishing method is trolling where multiple lines are towed behind a boat. Trolling gear used by the PIFSC have four troll lines each with 1-2 baited hooks towed at 4-6 kt.

Other nets

—PIFSC surveys utilize various small, fine-mesh, towed nets and neuston nets designed to sample

small fish and pelagic invertebrates. These nets can be broadly categorized as small trawls (which are separated from large trawl nets due to small trawls' discountable potential for interaction with marine mammals; see “Potential Effects of the Specified Activity on Marine Mammals and their Habitat”) and plankton nets.

1. Neuston nets are used to collect zooplankton that live in the top few centimeters of the sea surface (the neuston layer). These nets have a rectangular opening usually two or three times as wide as deep (

e.g.,

one meter by 0.5 meters or 60 centimeters by 20 centimeters). Neuston nets sometimes use hollow piping for construction of the net frame to aid in flotation. They are generally towed half submerged at 1-2 kt from the side of a vessel on a boom to avoid the ship's wake.

2. Ring nets are used to capture plankton with vertical tows. These nets consist of a circular frame and a cone-shaped net with a collection jar at the codend. The net, attached to a labeled dropline, is lowered into the water while maintaining the net's vertical position. When the desired depth is reached, the net is pulled straight up through the water column to collect the sample. The most common zooplankton ring net is one meter in diameter with 0.333 millimeter mesh openings, also known as a `meter net.'

3. Plankton drop nets are small handheld nets made up of fine mesh attached to a metal hoop with a long rope attached for retrieval. These nets are used for stationary sampling of the surrounding water.

4. Bongo nets are towed through the water at an oblique angle to sample plankton over a range of depths. Similar to ring nets, these nets typically have a cylindrical section coupled to a conical portion that tapers to a detachable codend constructed of nylon mesh. During each plankton tow, the bongo nets are deployed to depth and are then retrieved at a controlled rate so that the volume of water sampled is uniform across the range of depths. A collecting bucket, attached to the codend of the net, is used to contain the plankton sample. Some bongo nets can be opened and closed using remote control to enable the collection of samples from particular depth ranges. A group of depth-specific bongo net samples can be used to establish the vertical distribution of zooplankton species in the water column at a site. Bongo nets are generally used to collect zooplankton for research purposes and are not used for commercial harvest.

Traps

—Traps are submerged, three-dimensional devices, often baited, that permit organisms to enter the enclosure but make escape extremely difficult or impossible. Most traps are attached by a rope to a buoy on the surface of the water and may be deployed in series. The trap entrance can be regulated to control the maximum size of animal that can enter, and the size of the mesh in the body of the trap can regulate the minimum size that is retained. In general, the species caught depends on the type and characteristics of the pot or trap used. PIFSC uses lobster traps, crab traps, and other traps of various sizes.

Lobster traps are deployed in the NWHI to study the life history and population dynamics of lobster. The lobster traps consist of one string per site, with 8 or 20 traps per string, separated by 20 fathoms of ground line. The traps are deployed within two separate depth regimes: 10-20 or 21-35 fathoms.

Kona crab traps are nylon, with meshing spaced 2

1/2

inches apart attached to a wire ring with squid or fish bait set in the middle. Up to ten nets can be tied together with a buoy on the end net for retrieval. They are left for approximately 20 min.

Settlement traps are cylindrical with dimensions up to 3 m long and 2 m diameter. The trap frame is composed of semi-rigid plastic mesh of up to 5 cm mesh size. Folded plastic of up to 10 cm mesh is stuffed inside as settlement habitat, and cylinder ends are then pinched shut. The traps are clipped throughout the water column onto a vertical line anchored on bottom at up to 400 m, supported by a surface float.

Conductivity, temperature, and depth profilers

—A CTD profiler is the primary research tool for determining chemical and physical properties of seawater. A shipboard CTD is made up of a set of small probes attached to a large (1-2 m diameter) metal rosette wheel. The rosette is lowered through the water column on a cable, and CTD data are observed in real time via a conducting cable connecting the CTD to a computer on the ship. The rosette also holds a series of sampling bottles that can be triggered to close at different depths in order to collect a suite of water samples that can be used to determine additional properties of the water over the depth of the CTD cast. A standard CTD cast, depending on water depth, requires two to five hours to complete. The data from a suite of samples collected at different depths are often called a depth profile. Depth profiles for different variables can be compared in order to glean information about physical, chemical, and biological processes occurring in the water column. Salinity, temperature, and depth data measured by the CTD instrument are essential for characterization of seawater properties.

Expendable bathythermographs (XBT)

—PIFSC also uses XBTs to provide ocean temperature versus depth profiles. A standard XBT system consists of an expendable probe, a data processing/recording system, and a launcher. An electrical connection between the probe and the processor/recorder is made when the canister containing the probe is placed within the launcher and the launcher breech door is closed. Following launch into the water, wire de-reels from the probe as it descends vertically through the water. Simultaneously, wire de-reels from a spool within the probe canister, compensating for any movement of the ship and allowing the probe to freefall from the sea surface unaffected by ship motion or sea state.

Remotely operated vehicles (ROV)

—ROVs are used to count fish and shellfish, photograph fish for identification, and provide views of the bottom for habitat-type classification studies via still and video camera images. Precise georeferenced data from ROV platforms also enables SCUBA divers to utilize bottom time more effectively for collection of brood stock and other specimens.

PIFSC also uses various other platforms, including gliders, towed systems, and seafloor or moored packages, to conduct passive acoustic monitoring, collect oceanographic data, and collect photographic/video data, among other things. Many such deployments require the use of mooring lines, including the Bottom Camera system (BotCam), Modular Underwater Survey System (MOUSS), Baited Remote Underwater Video System (BRUVS), Underwater Sound Playback System, and High-Frequency Acoustic Recording (HARP) package.

Table 1.1 of the PIFSC's application provide detailed information of all surveys planned by PIFSC; full detail is not repeated here. Below, we provide brief summaries of a selection of surveys using gear expected to have potential for marine mammal interaction (Table 1). Many of these surveys also use small trawls, plankton nets, gear deployed by hand by divers, and/or other gear; however, only gear with likely potential for marine mammal interaction is described. These summaries illustrate projected annual survey effort in the different research areas for those gears that we believe present the potential for marine mammal interaction but are intended only to provide a sense of the level of effort, and actual level of effort may vary from year to year. Gear specifications vary; please see Table 1.1

of PIFSC's application for descriptions of representative equipment. All surveys generally may occur every year in the HARA, but approximately once every three years in the MARA, ASARA, and WCPRA. Figures 2.1-2.4 of PIFSC's application illustrate locations of past survey effort in each of the four research areas.

Table 1—Summary Description of PIFSC Fisheries and Ecosystem Research Activities in the Pacific Islands Region

Survey name

Survey description

General area of

operation

Season, frequency & yearly days at sea (DAS)

Gear used

Gear details

Total number of samples

(approximated)

Sampling Pelagic Stages of Insular Fish Species

Results of sampling inform life history and stock structure studies for pelagic larval and juvenile stage specimens of insular fish. Additional habitat information is also collected. Target species are snapper, grouper, and coral reef fish species within the 0-175 m depth range.

• HARA, MARA, ASARA, WCPRA

• 3-200 nmi from shore

• Year-round

• HARA: up to 20 Days at Sea (DAS)

• MARA, ASARA, WCPRA: up to 30 DAS

approximately once in research area every three years

• Midwater trawls are conducted at night, surface trawls are conducted day and night

• Cobb trawl (midwater trawl) or Isaacs-Kidd 10-foot (ft) net (midwater trawl)

• Isaacs-Kidd 6-ft net (surface trawl)

• Dip net (surface)

• Trawl mounted OES Netmind (midwater)

• Tow speed: 2.5-3.5 kt

• Duration: 60-240 minutes (min)

• Depth: deployed at various depths during same tow to target fish at different water depths, usually to 250 m

• Tow speed: 2.5-3.5 kts

• Duration: 60 min

• Depth: Surface

• 40 tows per survey per year.

• 40 tows per survey per year.

Spawning Dynamics of Highly Migratory Species

Early life history studies provide larval stages for population genetic studies and include the characterization of habitat for early life stages of pelagic species. Egg and larval collections are taken in surface waters using a variety of plankton gear, primarily Isaac- Kidd 6-foot surface trawl, but also sometimes including 1-meter ring net and surface neuston net.

• HARA, MARA, ASARA, WCPRA

• 1-25 nmi from shore

• Year-round.

• HARA: up to 25 DAS.

• MARA, ASARA, WCPRA: up to 25 DAS approximately once in research area every three years.

• Surface trawls are conducted day and night.

• Isaacs-Kidd 6-foot net (surface) Neuston tows (surface) 1-m ring net (surface)

• Tow speed: 2.5-3.5 kts

• Duration: 60 min

• Depth: Surface

• Tow Speed: 2.5-3.5 kts

• Duration: 30-60 min

• Depth: 0-3 m

• 140 tows per survey per year

• 140 tows per survey per year.

Cetacean Ecology Assessment

Survey transects conducted in conjunction with cetacean visual and acoustic surveys within the Hawai`i EEZ to develop ecosystem models for cetaceans. Sampling also includes active acoustics to determine relative biomass density of sound scattering layers; trawls to sample within the scattering layers; cetacean observations; surface and water column oceanographic measurements and water sample collection.

• HARA, MARA, ASARA, WCPRA

• Variable timing, depending on ship availability, up to 180 DAS

• Usually conducted in non-winter months

• Midwater trawls are conducted at night, surface trawls are conducted day and night

• Cobb trawl (midwater trawl)

• Small-mesh towed net (surface trawl)

• Tow speed: 3 kts

• Duration: 60-240 min

• Tow Speed: 2.5-3.5 kts

• Duration: 30-60 min

• 180 tows total per year.

• 180 tows per research area.

Marine Debris Research and Removal

Surface and midwater plankton tows to quantify floating microplastic in seawater

• HARA, MARA, ASARA, WCPRA

• Annually, or on an as- needed basis, up to 30 DAS

• Surface trawls are conducted day and night

• UAS are conducted during the day or night

• Neuston, or similar, plankton nets surface towed alongside ship and/or small boats

• Tow Speed: varied

• Duration: <1 hour

• Up to 250 tows per survey per year.

Insular Fish Life History Survey and Studies

Provide size ranges of deepwater eteline snappers, groupers, and large carangids to determine sex-specific length-at-age growth curves, longevity estimates, length and age at 50% reproductive maturity within the Bottomfish Management Unit Species (BMUS) in Hawai`i and the other Pacific Islands regions. Specimens are collected in the field and sampled at markets.

• HARA, MARA, ASARA, WCPRA

• 0.2-5 nmi from shore

• HARA: July-September, up to 15 DAS/yr

• Other areas: Year-round, up to 30 DAS for each research area once every three years

• Day and night

• Hook-and-line

• Hand line, electric or hydraulic reel

• Each operation involves 1-3 lines with.4-6 hooks per line; soaked 1-30 min

• Squid bait on circle hooks (typically 10/0 to 12/0)

• HARA: 350 operations per year.

• Other areas: 240 operations per year for each research area.

Pelagic Troll and Handline Sampling

Surveys would be conducted to collect life history and molecular samples from pelagic species. Other target species would be tagged-and-released. Different tags would used depending upon the species and study, but could include: passive, archival, ultrasonic, and satellite tags.

• HARA, MARA, ASARA

• 0 to 24 nmi from shore (excluding any special resource areas)

• Variable, up to 14 DAS Day and night

• Pelagic troll and handline (hook and line) fishing

• Troll fishing with up to 4 troll lines each with 1-2 baited hooks or 1-2 hook trolling lures at 4-10 kts

• Pelagic handline (hook-and-line) fishing at 10-100 m midwater depths, with hand, electric, or hydraulic reels. Up to 4 lines. Each line is baited with 4 hooks

• A total of up to 2 operations of any of these gear types per DAS, totaling 28 operations (all types combined) for the survey.

Insular fish Abundance Estimation Comparison Surveys

Comparison of fishery-independent methods to survey bottomfish assemblages in the Main Hawaiian Islands: coordinated research between PIFSC and various partners Day and night surveys are used to develop fishery-independent methods to assess stocks of economically important insular fish

• HARA, MARA, ASARA, WCPRA

• Variable, up to 30 DAS per research area per year

• HARA surveyed annually, ASARA, WCPRA surveyed every 3 years

• Sampling occurs day and night

• Hook-and-line

• Hand, electric, hydraulic reels.

• Each vessel fishes 2 lines. Each line is baited with 4-6 hooks.

• 1-30 minutes per fishing operation.

• HARA: 7,680 operations per year.

• MARA: 1.920 every 3rd year (average) 640 operations per year).

• ASARA: 1,920 every 3rd year (average e 640 per year).

• WCPRA: 1,920 every 3rd year (average 640 per year).

Kona Integrated Ecosystem Assessment Cruise

Survey transects conducted off the Kona coast and Kohala Shelf area to develop ecosystem models for coral reefs, socioeconomic indicators, circulation patterns, larval fish transport and settlement. Sampling includes active acoustics to determine relative biomass density of sound scattering layers; trawls to sample within the scattering layers; cetacean observations; surface and water column oceanographic measurements and water sample collection.

• HARA; 2-10 nmi from shore

• Variable timing, depending on ship availability, up to 10 DAS

• Day and night

• Cobb trawl (midwater trawl)

• Hook-and-line

• Tow speed: 3 kts

• Duration: 60-240 min

• Electric or hydraulic reel: Each operation involves 1-3 lines, with squid lures, soaked 10-60 min at depths between 200m to 600m

• 15-20 tows/yr.

• No more than 50 hours of effort.

• Approximately 10 mesopelagic squid caught per yr.

Sampling of Juvenile-stage Bottomfish via Settlement Traps

Sampling activity to capture juvenile recruits of eteline snappers and grouper that have recently transitioned from the pelagic to demersal habitat. Target species include Deep-7 bottomfish and the settlement habitats these stages are associated with

• HARA

• 0.2-5 nmi from shore

• July-September

• Up to 25 DAS Day and night

• Trap (settlement)

• Cylindrical traps are clipped throughout the water column onto a vertical line anchored on bottom at up to 400 m, supported by a surface float

• 10 traps per line set; up to 4 line sets soaked per day, from overnight up to 3 days.

• Up to 100 lines of traps set per yr.

• Catch of 2500 juvenile stage bottomfish per year.

Mariana Resource Survey

Sampling activity to quantify baseline bottomfish and reef fish resources in the Mariana Archipelago Research Area. Various artificial habitat designs, Cobb trawl and IK trawls will be developed, enclosed in mesh used to retain captures, and evaluated collect pelagic-stage specimens of reef fish and bottomfish species. Traps will be primarily set in mesophotic habitats (50-200 m depths) and in the quality of each habitat for recent recruits. deep-slope bottomfish habitats (200-500m depths)

• MARA

• 0-25 nmi from shore

• May—August Up to 102 DAS (once every three years)

• Midwater trawls are conducted at night, surface trawls are conducted day and night

• In-water activities are conducted during the day. All others are day and night

• Large-mesh Cobb midwater trawl Isaacs-Kidd midwater trawl

• Small-mesh surface trawl nets (Isaacs-Kidd, neuston, ring, bongo nets)

• Traps (Kona crab, enclosure)

• Hook-and-line

• Tow speed: 3 kts

• Duration: 60-240 min trawls; 2 tows per night

• Depth(s): deployed at various depths during same tow to target fish at different water depths, usually between 100 m and 200m

• Tow speed: 3 kts

• Duration: up to 60 min

• Depth: 0-200 m

• Up to ten Kona crab traps can be tied together with a buoy on the end net for retrieval. They are left for approximately 20 min. Two strings of six enclosure traps each would be deployed at night on sand, rubble and pavement (

i.e.

not coral) substrate, and retrieved the next morning

• Up to 20 traps per string, separated by 20 fathoms of ground line; two depths 10-35 fathoms

• Up to 2 strings per DAS

• Electric or hydraulic reel: each operation involves 1-3 lines, with squid lures, soaked 10-60 min at depths between 200 m to 600 m

• 15-20 tows per survey per year.

• 15-20 tows (any combination of the nets described).

• 25 gear sets per cruise.

• Up to 400 strings set per year.

• 1000 sets per survey.

Pelagic Longline, Troll, and Handline Gear Trials

Investigate effectiveness of various types of hooks, hook guards, gear configurations, or other modified fishing practices for reducing the bycatch of non-target species and retaining or increasing target catch

• HARA

• Longline fishing would occur outside of: (1) All longline exclusions zones in the Hawai`i EEZ; (2) the Insular False Killer Whale range, and (3) all special resource areas

• Longline fishing would occur up to approximately 500 nmi from the shores of the Hawai`i Archipelago

• Trolling and handline occurs 25 to 500 nmi from shore (excluding any special resource areas)

• 21 DAS

• Day and night

• Pelagic longline

• Trolling, and handline (hook-and-line)

• Soak time: 600-1800 min

• Troll fishing with up to 4 troll lines each with 1-2 baited hooks or 1-2 hook troll lures at 4-10 kts

• Pelagic handline (hook-and-line) fishing at 10-100 m midwater depths, with hand, electric, or hydraulic reels. Up to 4 lines. Each line is baited with 4 hooks

• Up to 4 hrs per troll or handline operation

• Up to 21 longline operations per year.

• Up to 21 troll or handline (combined) operations per year.

Pelagic Oceanographic Cruise

Investigate physical (

e.g.,

fronts) and biological features that define the habitats for important commercial and protected species of the North Pacific Ocean. Sampling also includes active acoustics to determine relative biomass density of sound scattering layers; trawls to sample within the scattering layers; surface and water column oceanographic measurements and water sample collection

• WCPRA

• 25-1000 nmi from shore in any direction

• Annual (season variable) Up to 30 DAS

• Midwater trawls are conducted at night, surface trawls are conducted day and night

• All other activities are conducted day and night

• Large-mesh Cobb midwater trawl

• Plankton drop net (stationary surface sampling)

• Small-mesh surface and midwater trawl nets (Isaacs-Kidd, neuston, ring, bongo nets)

• Tow speed: 3 kts

• Duration: 60-240 min

• 1 meter diameter plankton drop net would be deployed down to 100 m

• Duration: up to 60 min

• Depth: 0-200 m

• 20 tows per year, alternating with Kona IEA cruise 4 liters of micronekton per tow.

• 20 drops per year (collections would be less than one liter of plankton).

• 15-20 tows (any combination of the nets described) <1 liter of organisms per tow.

Lagoon Ecosystem Characterization

Measure the abundance and distribution of reef fish (including juvenile bumphead parrotfish)

• WCPRA

• Up to 14 DAS

• Conducted during the day

• Divers with hand net or speargun

• SCUBA, snorkel, 12-inch diameter small mesh hand net

• 10 dives per survey.

• 10 fin clips collected for genetic analyses.

• Hook-and-line

• Standard rod and reel using lures or fish bait from shoreline or small boat

• 1-30 minute casts.

• 60 casts per survey.

Description of Active Acoustic Sound Sources

—This section contains a brief technical background on sound, the characteristics of certain sound types, and on metrics used in this proposal inasmuch as the information is relevant to PIFSC's specified activity and to an understanding of the potential effects of the specified activity on marine mammals found later in this document. We also describe the active acoustic devices used by PIFSC. For general information on sound and its interaction with the marine environment, please see,

e.g.,

Au and Hastings (2008); Richardson

et al.

(1995); Urick (1983).

Sound travels in waves, the basic components of which are frequency, wavelength, velocity, and amplitude. Frequency is the number of pressure waves that pass by a reference point per unit of time and is measured in hertz (Hz) or cycles per second. Wavelength is the distance between two peaks or corresponding points of a sound wave (length of one cycle). Higher frequency sounds have shorter wavelengths than lower frequency sounds, and typically attenuate (decrease) more rapidly, except in certain cases in shallower water. Amplitude is the height of the sound pressure wave or the “loudness” of a sound and is typically described using the relative unit of the decibel (dB). A sound pressure level (SPL) in dB is described as the ratio between a measured pressure and a reference pressure (for underwater sound, this is 1 microPascal (μPa)) and is a logarithmic unit that accounts for large variations in amplitude; therefore, a relatively small change in dB corresponds to large changes in sound pressure. The source level (SL) represents the SPL referenced at a distance of 1 m from the source (referenced to 1 μPa), while the received level is the SPL at the listener's position (referenced to 1 μPa).

Root mean square (rms) is the quadratic mean sound pressure over the duration of an impulse. Root mean square is calculated by squaring all of the sound amplitudes, averaging the squares, and then taking the square root of the average. Root mean square accounts for both positive and negative values; squaring the pressures makes all values positive so that they may be accounted for in the summation of pressure levels. This measurement is often used in the context of discussing behavioral effects, in part because behavioral effects, which often result from auditory cues, may be better expressed through averaged units than by peak pressures. Peak sound pressure (also referred to as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous sound pressure measurable in the water at a specified distance from the source and is represented in the same units as the rms sound pressure (dB re 1 μPa).

Sound exposure level (SEL; represented as dB re 1 μPa

2

-second) represents the total energy in a stated frequency band over a stated time interval or event, and considers both intensity and duration of exposure. The per-pulse SEL is calculated over the time window containing the entire pulse (

i.e.,

100 percent of the acoustic energy). SEL is a cumulative metric; it can be accumulated over a single pulse, or calculated over periods containing multiple pulses. Cumulative SEL represents the total energy accumulated by a receiver over a defined time window or during an event.

When underwater objects vibrate or activity occurs, sound-pressure waves are created. These waves alternately compress and decompress the water as the sound wave travels. Underwater sound waves radiate in a manner similar to ripples on the surface of a pond and may be either directed in a beam or beams (as for the sources considered here) or may radiate in all directions (omnidirectional sources). The compressions and decompressions associated with sound waves are detected as changes in pressure by aquatic life and man-made sound receptors such as hydrophones.

Sounds are often considered to fall into one of two general types: Pulsed and non-pulsed (defined in the following paragraphs). The distinction between these two sound types is important because they have differing potential to cause physical effects, particularly with regard to hearing (

e.g.,

Ward, 1997 in Southall

et al.,

2007). Please see Southall

et al.

(2007) for an in-depth discussion of these concepts. The distinction between these two sound types is not always obvious, as certain signals share properties of both pulsed and non-pulsed sounds. A signal near a source could be categorized as a pulse; but, due to propagation effects as it moves farther from the source, the signal duration becomes longer (

e.g.,

Greene and Richardson, 1988). Pulsed sound sources (

e.g.,

airguns, explosions, gunshots, sonic booms, impact pile driving) produce signals that are brief (typically considered to be less than one second), broadband, atonal transients (ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur either as isolated events or repeated in some succession. Pulsed sounds are all characterized by a relatively rapid rise from ambient pressure to a maximal pressure value followed by a rapid decay period that may include a period of diminishing, oscillating maximal and minimal pressures, and generally have an increased capacity to induce physical injury as compared with sounds that lack these features. Non-pulsed sounds can be tonal, narrowband, or broadband, brief or prolonged, and may be either continuous or intermittent (ANSI, 1995; NIOSH, 1998). Some of these non-pulsed sounds can be transient signals of short duration but without the essential properties of pulses (

e.g.,

rapid rise time). Examples of non-pulsed sounds include those produced by vessels, aircraft, machinery operations such as drilling or dredging, vibratory pile driving, and active sonar systems. The duration of such sounds, as received at a distance, can be greatly extended in a highly reverberant environment. Non-pulsed sounds typically have less capacity to induce physical injury as compared with pulsed sounds. All active acoustic sources used by PIFSC produce non-pulsed intermittent sound.

A wide range of active acoustic sources are used in PIFSC fisheries surveys for remotely sensing bathymetric, oceanographic, and biological features of the environment. Most of these sources involve relatively high frequency, directional, and brief repeated signals tuned to provide sufficient focus and resolution on specific objects. PIFSC also uses passive listening sensors (

i.e.,

remotely and passively detecting sound rather than producing it), which do not have the potential to impact marine mammals. PIFSC active acoustic sources include various echosounders (

e.g.,

multibeam systems), scientific sonar systems, positional sonars (

e.g.,

net sounders for determining trawl position), and environmental sensors (

e.g.,

current profilers).

Mid- and high-frequency underwater acoustic sources typically used for scientific purposes operate by creating an oscillatory overpressure through rapid vibration of a surface, using either electromagnetic forces or the piezoelectric effect of some materials. A vibratory source based on the piezoelectric effect is commonly referred to as a transducer. Transducers are usually designed to excite an acoustic wave of a specific frequency, often in a highly directive beam, with the directional capability increasing with operating frequency. The main parameter characterizing directivity is the beam width, defined as the angle subtended by diametrically opposite “half power” (−3 dB) points of the main lobe. For different transducers at a single operating frequency the beam

width can vary from 180° (almost omnidirectional) to only a few degrees. Transducers are usually produced with either circular or rectangular active surfaces. For circular transducers, the beam width in the horizontal plane (assuming a downward pointing main beam) is equal in all directions, whereas rectangular transducers produce more complex beam patterns with variable beam width in the horizontal plane.

The types of active sources employed in fisheries acoustic research and monitoring, based largely on their relatively high operating frequencies and other output characteristics (

e.g.,

signal duration, directivity), should be considered to have very low potential to cause effects to marine mammals that would rise to the level of a “take,” as defined by the MMPA. Acoustic sources operating at high output frequencies (>180 kHz) that are outside the known functional hearing capability of any marine mammal are unlikely to be detected by marine mammals. Although it is possible that these systems may produce subharmonics at lower frequencies, this component of acoustic output would also be at significantly lower SPLs. While the production of subharmonics can occur during actual operations, the phenomenon may be the result of issues with the system or its installation on a vessel rather than an issue that is inherent to the output of the system. Many of these sources also generally have short duration signals and highly directional beam patterns, meaning that any individual marine mammal would be unlikely to even receive a signal that would likely be inaudible.

Acoustic sources present on most PIFSC fishery research vessels include a variety of single, dual, and multi-beam echosounders (many with a variety of modes), sources used to determine the orientation of trawl nets, and several current profilers with lower output frequencies that overlap with hearing ranges of certain marine mammals (

e.g.,

30-180 kHz). However, while likely potentially audible to certain species, these sources also have generally short ping durations and are typically focused (highly directional) to serve their intended purpose of mapping specific objects, depths, or environmental features. These characteristics reduce the likelihood of an animal receiving or perceiving the signal. A number of these sources, particularly those with relatively lower output frequencies coupled with higher output levels can be operated in different output modes (

e.g.,

energy can be distributed among multiple output beams) that may lessen the likelihood of perception by and potential impact on marine mammals; however, we have analyzed the effects of these sources under the assumption that they will be operating at frequencies and energy outputs that are most likely to be detected by marine mammals and may result in Level B harassment.

We now describe specific acoustic sources used by PIFSC. The acoustic system used during a particular survey is optimized for surveying under specific environmental conditions (

e.g.,

depth and bottom type). Lower frequencies of sound travel further in the water (

i.e.,

longer range) but provide lower resolution (

i.e.,

less precision). Pulse width and power may also be adjusted in the field to accommodate a variety of environmental conditions. Signals with a relatively long pulse width travel further and are received more clearly by the transducer (

i.e.,

good signal-to-noise ratio) but have a lower range resolution. Shorter pulses provide higher range resolution and can detect smaller and more closely spaced objects in the water. Similarly, higher power settings may decrease the utility of collected data. For example, power level is adjusted according to bottom type, as some bottom types have a stronger return and require less power to produce data of sufficient quality. Accordingly, power is typically set to the lowest level possible in order to receive a clear return with the best data. Survey vessels may be equipped with multiple acoustic systems; each system has different advantages that may be utilized depending on the specific survey area or purpose. In addition, many systems may be operated at one of two frequencies or at a range of frequencies. Primary source categories are described below, and characteristics of representative predominant sources are summarized in Table 2. Predominant sources are those that, when operated, would be louder than and/or have a larger acoustic footprint than other concurrently operated sources, at relevant frequencies.

(1)

Single and Multi-Frequency Narrow Beam Scientific Echosounders

—Echosounders and sonars work by transmitting acoustic pulses into the water that travel through the water column, reflect off the seafloor, and return to the receiver. Water depth is measured by multiplying the time elapsed by the speed of sound in water (assuming accurate sound speed measurement for the entire signal path), while the returning signal itself carries information allowing “visualization” of the seafloor. Multi-frequency split-beam echosounders are deployed from PIFSC survey vessels to acoustically map the distributions and estimate the abundances and biomasses of many types of fish; characterize their biotic and abiotic environments; investigate ecological linkages; and gather information about their schooling behavior, migration patterns, and avoidance reactions to the survey vessel. The use of multiple frequencies allows coverage of a broad range of marine acoustic survey activity, ranging from studies of small plankton to large fish schools in a variety of environments from shallow coastal waters to deep ocean basins. Simultaneous use of several discrete echosounder frequencies facilitates accurate estimates of the size of individual fish, and can also be used for species identification based on differences in frequency-dependent acoustic backscattering among species.

(2)

Multibeam Echosounder and Sonar

—Multibeam echosounders and sonars operate similarly to the devices described above. However, the use of multiple acoustic “beams” allows coverage of a greater area compared to single beam sonar. The sensor arrays for multibeam echosounders and sonars are usually mounted on the keel of the vessel and have the ability to look horizontally in the water column as well as straight down. Multibeam echosounders and sonars are used for mapping seafloor bathymetry, estimating fish biomass, characterizing fish schools, and studying fish behavior.

(3)

Acoustic Doppler Current Profiler (ADCP)

—An ADCP is a type of sonar used for measuring water current velocities simultaneously at a range of depths. Whereas current depth profile measurements in the past required the use of long strings of current meters, the ADCP enables measurements of current velocities across an entire water column. The ADCP measures water currents with sound, using the Doppler effect. A sound wave has a higher frequency when it moves towards the sensor (blue shift) than when it moves away (red shift). The ADCP works by transmitting “pings” of sound at a constant frequency into the water. As the sound waves travel, they ricochet off particles suspended in the moving water, and reflect back to the instrument. Due to the Doppler effect, sound waves bounced back from a particle moving away from the profiler have a slightly lowered frequency when they return. Particles moving toward the instrument send back higher frequency waves. The difference in frequency between the waves the profiler sends out and the waves it receives is called the Doppler shift. The instrument uses this shift to calculate how fast the

particle and the water around it are moving. Moreover, sound waves that hit particles far from the profiler take longer to come back than waves that strike close by. By measuring the time it takes for the waves to return to the sensor, and the Doppler shift, the profiler can measure current speed at many different depths with each series of pings.

An ADCP anchored to the seafloor can measure current speed not just at the bottom, but at equal intervals to the surface. An ADCP instrument may be anchored to the seafloor or can be mounted to a mooring or to the bottom of a boat. ADCPs that are moored need an anchor to keep them on the bottom, batteries, and a data logger. Vessel-mounted instruments need a vessel with power, a shipboard computer to receive the data, and a GPS navigation system so the ship's movements can be subtracted from the current velocity data. ADCPs operate at frequencies between 75 and 300 kHz.

(4)

Net Monitoring Systems

—During trawling operations, a range of sensors may be used to assist with controlling and monitoring gear. Net sounders give information about the concentration of fish around the opening to the trawl, as well as the clearances around the opening and the bottom of the trawl; catch sensors give information about the rate at which the codend is filling; symmetry sensors give information about the optimal geometry of the trawls; and tension sensors give information about how much tension is in the warps and sweeps.

Table 2—Operating Characteristics of Representative Predominant PIFSC Active Acoustic Sources

Active acoustic system

Operating frequencies

Maximum source level

Single ping duration (ms) and repetition rate (Hz)

Orientation/directionality

Nominal beamwidth

Simrad EK60 narrow beam echosounder

38, 70, 120, 200 kHz

224 dB

1 ms at 1 Hz

Downward looking

7°

Simrad EM300 multibeam echosounder

30 kHz

237 dB

0.7-15 ms at 5 Hz

Downward looking

1°

ADCP Ocean Surveyor

75 kHz

223.6 dB

1 ms at 4 Hz

Downward looking (30° tilt)

4°

Netmind

30, 200 kHz

190 dB

up to 0.3 ms at 7-9 Hz

Trawl-mounted

50°

Nearshore and Land-based Surveys

—The Pacific Reef Assessment and Monitoring Program (RAMP) and Marine Debris Research and Removal Surveys involve circumnavigating islands and atolls using small vessels that may approach the shoreline. Additionally, the Marine Debris Research and Removal Surveys may involve land vehicle (trucks) operations in areas of marine debris where vehicle access is possible from highways or rural/dirt roads adjacent to coastal resources. The RAMP and Marine Debris Research and Removal Surveys have the potential to disturb pinnipeds hauled out during research activities either from approaches of nearshore small vessel based research or land based debris research and clean-up activities.

Description of Marine Mammals in the Area of the Specified Activity

We have reviewed PIFSC's species descriptions—which summarize available information regarding status and trends, distribution and habitat preferences, behavior and life history, and auditory capabilities of the potentially affected species—for accuracy and completeness and refer the reader to Sections 3 and 4 of PIFSC's application, instead of reprinting the information here (note that PIFSC provides additional information regarding marine mammal observations around the Main Hawaiian Islands in Table 3.3 of their application, including information about group size and seasonality). Additional information regarding population trends and threats may be found in NMFS's Stock Assessment Reports (SAR;

www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments

) and more general information about these species (

e.g.,

physical and behavioral descriptions) may be found on NMFS's website (

www.fisheries.noaa.gov/find-species

).

Table 3 lists all species with expected potential for occurrence in the specified geographical regions where PIFSC proposes to conduct the specified activity and summarizes information related to the population or stock, including regulatory status under the MMPA and ESA and potential biological removal (PBR), where known. For taxonomy, we follow the Society for Marine Mammalogy Committee on Taxonomy (2020). PBR, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population, is discussed in greater detail later in this document (see “Negligible Impact Analysis”).

Stocks are not designated for most species in areas of the specified geographical regions outside of the Hawaiian EEZ. Therefore, while all species with expected potential for occurrence in the specified geographical regions are listed in Table 3, the listed stocks are in most cases specific to the Hawaiian EEZ. The only exceptions are NMFS-designated stocks for the humpback whale, rough-toothed dolphin, spinner dolphin, and false killer whale in American Samoa (animals belonging to these stocks would occur in the ASARA), and a false killer whale stock designated for Palmyra Atoll (animals belonging to this stock would occur in the WCPRA). With the exception of the humpback whale, which is discussed in greater detail following Table 3, and the aforementioned Palmyra Atoll stock of false killer whale, animals of any species occurring in the MARA or areas of the WCPRA outside of the Hawaiian EEZ and American Samoa EEZ would not be part of any NMFS-designated stock. Aside from the four species listed above, animals of any species occurring in the American Samoa EEZ would not be part of any NMFS-designated stock. As a reminder, the HARA, MARA, and ASARA are considered to include waters of the contiguous zone around these archipelagoes (

i.e.,

0-24 nmi from land), while the WCPRA is considered to include all remaining EEZ waters around those archipelagoes as well as the high seas and waters around U.S. possessions of the Pacific Remote Islands Area.

Marine mammal abundance estimates presented in this document represent the total number of individuals that

make up a given stock or the total number estimated within a particular study or survey area. Abundance estimates and related information, PBR values, and annual M/SI values given in Table 3 are specific to the stocks for which they are listed. This information is generally not available for these species occurring in areas outside the ranges of NMFS-designated stocks. NMFS-designated stocks in the Hawai'i region include animals found both within the Hawaiian Islands EEZ and in adjacent high seas waters; however, because data on abundance, distribution, and human-caused impacts are largely lacking for high seas waters, the status of these stocks are generally evaluated based on data from the U.S. EEZ waters of the Hawaiian Islands (including the Main Hawaiian Islands and Northwestern Hawaiian Islands). For certain species, existing data support the existence of demographically distinct resident populations associated with different regions within the Hawaiian Islands, and separate stocks are designated accordingly. NMFS-designated stocks for American Samoa include animals occurring within U.S. EEZ waters around American Samoa. All managed stocks in the specified geographical regions are assessed in either NMFS's U.S. Pacific SARs or U.S. Alaska SARs. All values presented in Table 3 are the most recent available at the time of writing and are available online at:

www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

Twenty-six species (with 46 managed stocks; no stock is designated for Deraniyagala's beaked whale) are considered to have the potential to co-occur with and potentially be taken by PIFSC activities. Species that could potentially occur in the research areas but are not expected to have the potential for interaction with PIFSC research gear or that are not likely to be harassed by PIFSC's use of active acoustic devices are described briefly but omitted from further analysis. These include extralimital species, which are species that do not normally occur in a given area but for which there are one or more occurrence records that are considered beyond the normal range of the species. Extralimital species or stocks include the North Pacific right whale (

Eubalaena japonica;

all areas except ASARA), Omura's whale (

Balaenoptera omurai;

all areas), Antarctic minke whale (

B. bonaerensis;

ASARA and WCPRA), southern bottlenose whale (

Hyperoodon planifrons;

ASARA and WCPRA), common dolphin (

Delphinus delphis;

all areas), northern elephant seal (

Mirounga angustirostris;

HARA and WCPRA), and northern fur seal (

Callorhinus ursinus;

HARA and WCPRA).

Table 3—Marine Mammals Potentially Present in the Vicinity of PIFSC Research Activities

Common name

Scientific name

Stock

1

Occurrence

2

H

A

R

A

M

A

R

A

A

S

A

R

A

W

C

P

R

A

ESA/MMPA status; strategic (Y/N)

3

Stock abundance

(CV, N

min

, most recent

abundance survey)

4

PBR

Annual M/SI

5

Order Cetartiodactyla—Cetacea—Superfamily Mysticeti (baleen whales)

Family Balaenopteridae (rorquals)

Humpback whale *

Megaptera novaeangliae kuzira

American Samoa

Central North Pacific (CNP)

X

X

X

X

-; N

E/D; Y

unk (n/a; 150; 2008)

10,103 (0.3; 7,891; 2006)

0.4

83

0

25

Western North Pacific

E/D; Y

1,107 (0.3; 865; 2006)

3

2.6

Minke whale

Balaenoptera acutorostrata scammoni

Hawaii

X

X

X

X

-; N

unk

undet

0

Bryde's whale

B. edeni brydei

Hawaii

X

X

X

X

-; N

1,751 (0.29; 1,378; 2010)

13.8

0

Sei whale

B. borealis borealis

Hawaii

X

X

X

E/D; Y

391 (0.9; 204; 2010)

0.4

0.2

Fin whale

B. physalus physalus

Hawaii

X

X

X

E/D; Y

154 (1.05; 75; 2010)

0.1

0

Blue whale

B. musculus musculus

CNP

X

X

X

E/D; Y

133 (1.09; 63; 2010)

0.1

0

Superfamily Odontoceti (toothed whales, dolphins, and porpoises)

Family Physeteridae

Sperm whale

Physeter macrocephalus

Hawaii

X

X

X

X

E/D; Y

4,559 (0.33; 3,478; 2010)

13.9

0.7

Family Kogiidae

Pygmy sperm whale

Kogia breviceps

Hawaii

X

X

X

-; N

unk

undet

0

Dwarf sperm whale

K. sima

Hawaii

6

X

X

X

X

-; N

unk

undet

0

Family Ziphiidae (beaked whales)

Cuvier's beaked whale

Ziphius cavirostris

Hawaii

X

X

X

X

-; N

723 (0.69; 428; 2010)

4.3

0

Longman's beaked whale

Indopacetus pacificus

Hawaii

X

X

-; N

7,619 (0.66; 4,592; 2010)

46

0

Blainville's beaked whale

Mesoplodon densirostris

Hawaii

X

X

X

-; N

2,105 (1.13; 980; 2010)

10

0

Deraniyagala's beaked whale

M. hotaula

n/a

X

-; N

unk

undet

unk

Family Delphinidae

Rough-toothed dolphin *

Steno bredanensis

Hawaii

X

X

X

X

-; N

72,528 (0.39; 52,833; 2010)

423

2.1

American Samoa

-; N

unk

undet

unk

Common bottlenose dolphin *

Tursiops truncatus truncatus

Hawai'i Pelagic

X

X

X

X

-; N

21,815 (0.57; 13,957; 2010)

140

0

Kauai and Ni'ihau

-; N

184 (0.11; 97; 2015)

1.0

unk

Oahu

6

-; N

743 (0.54; 388; 2006)

undet

unk

4-Island Region

6

-; N

191 (0.24; unk; 2006)

undet

unk

Hawai'i Island

-; N

128 (0.13; 91; 2013)

0.9

unk

Pantropical spotted dolphin *

Stenella attenuata attenuata

Hawai'i Pelagic

X

X

X

X

-; N

55,795 (0.4; 40,338; 2010)

403

0

Oahu

-; N

unk

undet

unk

4-Island Region

-; N

unk

undet

unk

Hawai'i Island

-; N

unk

undet

≥ 0.2

Spinner dolphin *

S. longirostris longirostris

Hawai'i Pelagic

Kauai and Ni'ihau

X

X

X

X

-; N

-; N

unk

601 (0.2; unk; 2005)

undet

undet

0

unk

Oahu/4-Island Region

-; N

355 (0.09; unk; 2007)

undet

unk

Hawai'i Island

-; N

665 (0.09; 617; 2012)

6.2

unk

Kure and Midway Atoll

6

-; N

260 (n/a; 139; 1998)

undet

unk

Pearl and Hermes Reef

-; N

unk

undet

unk

American Samoa

-; N

unk

undet

unk

Striped dolphin

S. coeruleoalba

Hawai'i Pelagic

X

X

X

-; N

61,021 (0.38; 44,922; 2010)

449

0

Fraser's dolphin

Lagenodelphis hosei

Hawaii

X

X

X

-; N

51,491 (0.66; 31,034; 2010)

310

0

Risso's dolphin

Grampus griseus

Hawaii

X

X

X

-; N

11,613 (0.43; 8,210; 2010)

82

0

Melon-headed whale *

Peponocephala electra

Hawaii

X

X

X

-; N

8,666 (1.0; 4,299; 2010)

43

0

Kohala Resident

-; N

447 (0.12; 404; 2009)

4

0

Pygmy killer whale

Feresa attenuata

Hawaii

X

X

X

-; N

10,640 (0.53; 6,998; 2010)

56

1.1

False killer whale *

Pseudorca crassidens

Northwestern Hawaiian Islands

X

X

X

X

-; N

617 (1.11; 290; 2010)

2.3

0.4

Hawai'i Pelagic

-; N

1,540 (0.66; 928; 2010)

9.3

7.6

Hawai'i Insular

E/D; Y

167 (0.14; 149; 2015)

0.3

0

American Samoa

-; N

unk

undet

unk

Palmyra Atoll

-; N

1,329 (0.65; 806; 2005)

6.4

0.3

Killer whale

Orcinus orca

Hawaii

X

X

X

X

-; N

146 (0.96; 74; 2010)

0.7

0

Short-finned pilot whale

Globicephala macrorhynchus

Hawaii

X

X

X

X

-; N

19,503 (0.49; 13,197; 2010)

106

0.9

Order Carnivora—Superfamily Pinnipedia

Family Phocidae (earless seals)

Hawaiian monk seal *

Neomonachus schauinslandi

Hawaii

X

X

E/D; Y

1,351 (0.03; 1,325; 2017)

4.6

≥1.6

* Species marked with an asterisk are addressed in further detail in text below. Additional detail for all species may be found in Sections 3 and 4 of PIFSC's application.

1

All species with potential for take by PIFSC are presented in Table 1. All known stocks are presented here but marine mammals in the MARA, ASARA, and WCPRA are generally not assigned to designated stocks.

2

HARA: Hawaiian Archipelago Research Area; MARA: Mariana Archipelago Research Area; ASARA: American Samoa Archipelago Research Area; WCPRA: Western and Central Pacific Research Area.

3

Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.

4

CV is coefficient of variation; N

min

is the minimum estimate of stock abundance.

5

These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (

e.g.,

commercial fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value.

6

Abundance estimates for these stocks are not considered current. PBR is therefore considered undetermined for these stocks, as there is no current minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates, as these represent the best available information for use in this document.

Humpback Whale

—Prior to 2016, humpback whales were listed under the ESA as an endangered species worldwide. Following a 2015 global status review (Bettridge

et al.,

2015), NMFS established 14 distinct population segments (DPS) with different listing statuses (81 FR 62259; September 8, 2016) pursuant to the ESA. The DPSs that occur in U.S. waters do not necessarily equate to the existing stocks designated under the MMPA and shown in Table 2. Because MMPA stocks cannot be portioned,

i.e.,

parts managed as ESA-listed while other parts managed as not ESA-listed, until such time as the MMPA stock delineations are reviewed in light of the DPS designations, NMFS considers the existing humpback whale stocks under the MMPA to be endangered and depleted for MMPA management purposes (

e.g.,

selection of a recovery factor, stock status).

Within western and central Pacific waters, three DPSs may occur: The Western North Pacific (WNP) DPS (endangered), Hawai'i DPS (not listed), and Oceania DPS (not listed). Whales encountered in the HARA would be from the Hawai'i DPS; whales encountered in the MARA from the WNP DPS; and whales encountered in the ASARA from the Oceania DPS. While not possible to know in advance the identity of whales encountered in the WCPRA, in reality the DPS identity would likely be determined based on proximity to either the HARA, MARA, or ASARA. PIFSC has requested authorization of humpback whale take by M/SI only for the CNP stock (

i.e.,

Hawai'i DPS) and has not requested take of humpback whales (from any stock) by

Level B harassment; see “Estimated Take” section.

With regard to abundance, an updated analysis of data from the Structure of Populations, Levels of Abundance and Status of Humpback Whales in the North Pacific (SPLASH) study provided an estimate of 21,808 (CV = 0.04) humpback whales in the North Pacific Ocean (Barlow

et al.,

2011). Bettridge

et al.

(2015) stated that this estimate may still be an underestimate of actual humpback whale abundance due to biases that could not be corrected for using the available data. Calambokidis

et al.

(2008) approximated the size of the whale populations frequenting each breeding area at 10,000 individuals in Hawai'i and 1,000 for the WNP areas. Although Barlow

et al.

(2011) did not apportion their estimate to individual breeding areas, Bettridge

et al.

(2015) state that the proportions are likely to be similar to those estimated by Calambokidis

et al.

(2008) and therefore about 20 percent larger than the Calambokidis

et al.

(2008) estimates,

i.e.,

12,000 individuals in the Hawai'i DPS and 1,200 individuals in the WNP DPS. The size of the Oceania DPS has been estimated at 3,827 (CV = 0.12) whales for a portion of the DPS breeding range covering New Caledonia, Tonga, French Polynesia, and the Cook Islands (SPWRC, 2006).

In winter, most humpback whales occur in the subtropical and tropical waters of the Northern and Southern Hemispheres, then migrate to higher latitudes in the summer to feed (Muto

et al.,

2018). Peak abundance in Hawaiian waters occurs from late-February to early-April (Mobley

et al.,

2001). The Hawaiian Islands Humpback Whale National Marine Sanctuary (HIHWNMS) was established in 1992 by the U.S. Congress to protect humpback whales and their habitat in Hawai'i (NOAA 2018a). The sanctuary provides essential breeding, calving, and nursing areas necessary for the long-term recovery of the North Pacific humpback whale population. The HIHWNMS provides protection to humpbacks in the shallow waters (from the shoreline to a depth of 100 fathoms or 183 m) around the four islands area of Maui, Penguin Bank; off the north shore of Kauai, the north and south shores of Oahu, and the north Kona and Kohala coast of the island of Hawai'i (NOAA 2018a). These areas, as well as some of the waters surrounding them, are also considered biologically important areas (BIAs) for reproduction (Table 3; Baird

et al,.

2015).

Please see Caretta

et al.

(2019) for additional information on the Central North Pacific and Western North Pacific stocks, and Caretta

et al.

(2009) for additional information on the American Samoa stock.

Rough-toothed Dolphin

—Rough-toothed dolphins are found throughout the world in tropical and warm-temperate waters. They are present around all the MHI and have been observed close to the islands and atolls at least as far northwest as Pearl and Hermes Reef in the NWHI. Although analysis of genetic samples indicates that designation of a separate Hawai'i Island stock may be warranted, only a single Hawai'i stock has been designated. Waters off the west side of Hawai'i Island have been identified as a BIA for the small and resident population of rough-toothed dolphins (Table 4; Baird

et al.,

2015). Rough-toothed dolphins are common in the South Pacific from the Solomon Islands to French Polynesia and the Marquesas, and have been among the most commonly observed cetaceans during summer and winter surveys conducted from 2003-06 around the American Samoan island of Tutuila (though they were not observed during 2006 surveys of Swain's Island and the Manua Group). In addition, a rough-toothed dolphin was caught incidentally in the American Samoa-based longline fishery in 2008, indicating that some dolphins maintain a more pelagic distribution. Rough-toothed dolphins are thought to be common throughout the Samoan archipelago. No abundance estimates are available for rough-toothed dolphins in American Samoa, though investigation of published density estimates for rough-toothed dolphins in other tropical Pacific regions yields a plausible abundance estimate range of 692-3,115 rough-toothed dolphins in the American Samoa EEZ. Therefore, a plausible range of PBR values would be 3.4-22 dolphins (assuming a default growth rate and recovery factor of 0.4) (Carretta

et al.,

2015). Please see Carretta

et al.

(2015, 2018) for more information about these stocks.

Bottlenose Dolphin

—Bottlenose dolphins are widely distributed throughout the world in tropical and warm-temperate waters. The species is primarily coastal in much of its range, but there are populations in some offshore deepwater areas as well. Bottlenose dolphins are common throughout the Hawaiian Islands, from the island of Hawai'i to Kure Atoll, and are found in shallow inshore waters and deep water. Baird

et al.

(2015) identified three BIAs in the Hawaiian Archipelago for small and resident populations of bottlenose dolphins (Table 3). Photo-identification and genetic studies in the MHI suggest limited movement of bottlenose dolphins between islands and offshore waters and the existence of demographically distinct resident populations at each of the four MHI island groups (as reflected in the current stock designations). Genetic data support inclusion of bottlenose dolphins in deeper waters surrounding the MHI as part of the broadly distributed pelagic population which, in Hawaiian waters, is managed as a pelagic stock. The boundary between the pelagic stock and insular stocks is placed at the 1,000-m isobath (the boundary between the Oahu and 4-Islands stocks is designated as equidistant between the 500 m isobaths around Oahu and the 4-Islands Region, through the middle of Kaiwi Channel). Although it is likely that additional demographically independent populations of bottlenose dolphins exist in the NWHI, those animals are considered part of the pelagic stock until additional data become available upon which to base stock designations. Photo-identification studies conducted from 2012-15 identified a minimum of 97 distinct individuals in the Kauai-Ni'ihau stock (Table 2), though earlier photo-identification studies conducted from 2003-05 (and now considered outdated) resulted in an abundance estimate of 147 (CV = 0.11), or 184 animals when corrected for the proportion of marked individuals (Baird

et al.,

2009). Similarly for the Hawai'i Island stock, photo-identification studies conducted from 2000-06 (and now considered outdated) resulted in an abundance estimate of 102 (CV = 0.13), or 128 animals when corrected for the proportion of marked individuals (Baird

et al.,

2009), whereas later studies conducted from 2010-13 identified a minimum of 91 distinct individuals (Table 2). For both of these stocks, a current PBR value is calculated using the more recent minimum abundance estimates. Available abundance information for other bottlenose dolphin stocks is shown in Table 3. Please see Carretta

et al.

(2018) for additional information about these stocks of bottlenose dolphin.

Pantropical Spotted Dolphin

—Pantropical spotted dolphins are primarily found in tropical and subtropical waters worldwide, and have been observed in all months of the year around the MHI, in areas ranging from shallow nearshore water to depths of 5,000 m, although sighting rates peak in depths from 1,500 to 3,500 m. As with bottlenose dolphins, genetic analyses suggest the existence of island-associated stocks. However, although commonly observed off of three of the

MHI island groups, they are largely absent from waters around Kauai and Ni'ihau, and only three insular stocks are designated. The Oahu and 4-Islands stocks are considered to include animals within 20 km of those island groups, whereas the Hawai'i Island stock includes animals within 65 km of Hawai'i Island. The pelagic stock includes animals occurring in Hawaiian EEZ and adjacent high seas waters outside these insular stock areas. No abundance information is available for the insular stocks. Baird

et al.

(2015) identified two BIAs for small and resident populations of pantropical spotted dolphins in the Hawaiian Archipelago (Table 3). Please see Carretta

et al.

(2018) for additional information about these stocks.

Spinner Dolphin—

Spinner dolphins occur in all tropical and most sub-tropical waters between 30-40° N and 20-40° S latitude, generally in areas with a shallow mixed layer, shallow and steep thermocline, and little variation in surface temperature (Perrin 2009a). Within the central and western Pacific, spinner dolphins are island-associated and use shallow protected bays to rest and socialize during the day then move offshore at night to feed. They are common in nearshore waters throughout the Hawaiian archipelago (Carretta

et al.,

2012). There are seven stocks found within the PIFSC fisheries and ecosystem research areas: (1) Hawai`i Island, (2) Oahu/4-Islands, (3) Kauai/Ni`ihau, (4) Pearl & Hermes Reef, (5) Kure/Midway, (6) Hawai`i pelagic, including animals found both within the Hawaiian Islands EEZ (outside of island-associated boundaries) and in adjacent international waters, and (7) the American Samoa stock, which includes animals inhabiting the U.S. EEZ waters around American Samoa. Baird

et al.

identified five BIAs for small and resident populations of spinner dolphins within the Hawaiian Archipelago (Table 3). Please see Caretta

et al.

(2019) for additional information about the Hawaiian Island Stocks Complex (including the Hawai'i Island, Oahu/4-islands, Kauai/Ni'ihau, Pearl & Hermes Reef, Midway Atoll/Kure, Hawai'i Pelagic stocks) and Caretta

et al.

(2011) for additional information on the American Samoa stock.

Melon-headed Whale—

Melon-headed whales are distributed worldwide in tropical and warm-temperate waters. The distribution of reported sightings suggests that the oceanic habitat of this species is in primarily equatorial waters (Perryman

et al.,

1994). They generally occur offshore in deep oceanic waters. Nearshore distribution is generally associated with deep water areas near to the coast (Perryman 2009). Photo-identification and telemetry studies suggest there are two demographically-independent populations of melon-headed whales in Hawaiian waters, the Hawaiian Islands stock and the Kohala resident stock (Carretta

et al.,

2015). The Hawaiian Islands stock includes melon-headed whales inhabiting waters throughout the U.S. EEZ of the Hawaiian Islands, including the area of the Kohala resident stock, and adjacent high seas waters, and (2) the Kohala resident stock, which includes melon-headed whales off the Kohala Peninsula and west coast of Hawai`i Island and in less than 2500m of water. At this time, assignment of individual melon-headed whales within the overlap area to either stock requires photographic-identification of the animal. Resighting data and social network analyses of photographed individuals indicate very low rates of interchange between the Hawaiian Islands and Kohala resident stocks (Aschettino

et al.,

2012). This finding is supported by preliminary genetic analyses that suggest a restricted gene flow between the Kohala residents and other melon-headed whales sampled in Hawaiian waters (Oleson

et al.,

2013). Baird

et al.

(2015) identified a BIA for the small and resident Kohola stock of melon-headed whales off the northwestern tip of Hawai'i Island (Table 3). Please see Caretta

et al.

(2018) for additional information about these stocks.

False Killer Whale

—False killer whales occur throughout tropical and warm temperate waters worldwide. They are largely pelagic, but also occur nearshore and in shallow waters around oceanic islands (Baird 2009b). Five stocks are recognized in the U.S. EEZ of the Pacific Ocean: (1) The Main Hawaiian Islands insular stock, which includes animals found within 72 km (38.9 nm) of the MHIs; (2) the NWHI stock, which includes animals inhabiting waters within the NWHI and a 50 nmi radius around Kauai; (3) the Hawai`i pelagic stock, which includes animals found inhabiting waters greater than 11 km (5.9 nmi) from the MHI, including adjacent high seas waters; (4) the Palmyra Atoll stock, which includes animals found within the U.S. EEZ of Palmyra Atoll; and (5) the American Samoa stock, which includes animals found within the U.S. EEZ of American Samoa. On August 23, 2018, NMFS designated waters from the 45-m depth contour to the 3,200-m depth contour around the main Hawaiian Islands from Ni'ihau east to Hawai'i as critical habitat for the Main Hawaiian Islands insular DPS of false killer whales (83 FR 35062; July 24, 2018). Additionally, Baird

et al.

(2015) identified waters throughout the MHI as a BIA for the small and resident Main Hawaiian Islands insular stock of false killer whales (Table 3). As described in detail below, a take reduction plan was finalized in 2012 to address high rates of false killer whale mortality and serious injury in Hawai'i-based longline fisheries. Please see Caretta

et al.

(2018) for additional information on the Hawaiian Islands Stock Complex (including the MHI Insular stock, NWHI stock, and Hawai'i pelagic stock), and Caretta

et al.

(2011) and (2012) for additional information on the American Samoa and Palmyra Atoll stocks, respectively.

Hawaiian monk seal

—The majority of the Hawaiian monk seal population can be found around the NWHI, but a small and growing population lives around the MHIs. As summarized in Carretta

et al.

(2014, 2012, and citations herein), Hawaiian monk seals are distributed predominantly in six NWHI subpopulations at French Frigate Shoals, Laysan and Lisianski Islands, Pearl and Hermes Reef, and Midway and Kure Atoll. They also occur at Necker and Nihoa Islands, which are the southernmost islands in the NWHI. Genetic variation among NWHI monk seals is extremely low and may reflect both a long-term history at low population levels and more recent human influences (Schultz

et al.

2008). On average, 10-15 percent of the seals migrate among the NWHI subpopulations. Thus, the NWHI subpopulations are not isolated, though the different island subpopulations have exhibited considerable demographic independence. Observed interchange of individuals among the NWHI and MHI regions is uncommon, and genetic stock structure analysis supports management of the species as a single stock. Please see Caretta

et al.

(2019) for additional information on this species.

Take Reduction Planning

—Take reduction plans are designed to help recover and prevent the depletion of strategic marine mammal stocks that interact with certain U.S. commercial fisheries, as required by Section 118 of the MMPA. The immediate goal of a take reduction plan is to reduce, within six months of its implementation, the M/SI of marine mammals incidental to commercial fishing to less than the PBR level. The long-term goal is to reduce, within five years of its implementation, the M/SI of marine mammals incidental to commercial fishing to insignificant levels, approaching a zero serious injury and mortality rate, taking into account the economics of the fishery, the availability of existing technology, and

existing state or regional fishery management plans. Take reduction teams are convened to develop these plans.

For marine mammals off Hawaii, there is currently one take reduction plan in effect (False Killer Whale Take Reduction Plan). The goal of this plan is to reduce M/SI of false killer whales in Hawaii-based deep-set and shallow-set longline fisheries; the plan addresses only the Hawai'i Insular and Hawai'i Pelagic stocks of false killer whale. A team was convened in 2010 and a final plan produced in 2012 (77 FR 71260; November 29, 2012). The most recent five-year averages of M/SI for these stocks are below PBR. More information is available online at:

www.fisheries.noaa.gov/national/marine-mammal-protection/false-killer-whale-take-reduction.

PIFSC has requested the authorization of incidental M/SI for false killer whale; however, this take is expected to potentially occur only for the Hawai'i Pelagic stock or for false killer whales belonging to unspecified stocks and occurring in high seas waters (see “Estimated Take” later in this document). PIFSC longline research would not occur within the ranges of other designated stocks of false killer whale.

Regulatory measures required by the plan include gear requirements, longline prohibited areas, training and certification in marine mammal handling and release, captains' supervision of marine mammal handling and release, and posting of NMFS-approved placards on longline vessels. On July 18, 2018, NMFS issued a temporary rule (83 FR 33848) to close one of the prohibited areas to deep-set longline fishing for the remainder of the calendar year, because a bycatch trigger established per the regulations implementing the plan was met. PIFSC does not conduct research with longline gear within any of the exclusion zones established by the plan, and PIFSC longline gear adheres to all relevant requirements placed on commercial gear. PIFSC is not conducting commercial fishing as described by the MMPA, but PIFSC is adhering to these commercial fishing restrictions nevertheless. There are no take reduction plans currently in effect for fisheries in American Samoa, the Marianas, or other locations considered herein.

Unusual Mortality Events (UME)

—A UME is defined under the MMPA as “a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response.” Based on records from 1991 to the present, there have not been any formally recognized UMEs in the Pacific Islands. However, some migratory whales may have been impacted by UMEs occurring in Alaska. For more information on UMEs, please visit:

www.fisheries.noaa.gov/national/marine-life-distress/marine-mammal-unusual-mortality-events.

Biologically Important Areas

In 2015, NOAA's Cetacean Density and Distribution Mapping Working Group identified Biologically Important Areas (BIAs) for 24 cetacean species, stocks, or populations in seven regions (US East Coast, Gulf of Mexico, West Coast, Hawaiian Islands, Gulf of Alaska, Aleutian Islands and Bering Sea, and Arctic) within U.S. waters through an expert elicitation process. BIAs are reproductive areas, feeding areas, migratory corridors, and areas in which small and resident populations are concentrated. BIAs are region-, species-, and time-specific. A description of the types of BIAs found within PIFSC fishery research areas follows:

Reproductive Areas:

Areas and months within which a particular species or population selectively mates, gives birth, or is found with neonates or other sensitive age classes.

Feeding Areas:

Areas and months within which a particular species or population selectively feeds. These may either be found consistently in space and time, or may be associated with ephemeral features that are less predictable but can be delineated and are generally located within a larger identifiable area.

Migratory Corridors:

Areas and months within which a substantial portion of a species or population is known to migrate; the corridor is typically delimited on one or both sides by land or ice.

Small and Resident Population:

Areas and months within which small and resident populations occupying a limited geographic extent exist.

The delineation of BIAs does not have direct or immediate regulatory consequences. Rather, the BIA assessment is intended to provide the best available science to help inform analyses and planning for applicants, and to support regulatory and management decisions under existing authorities, and to support the reduction of anthropogenic impacts on cetaceans and to achieve conservation and protection goals. In addition, the BIAs and associated information may be used to identify information gaps and prioritize future research and modeling efforts to better understand cetaceans, their habitat, and ecosystems. Table 4 provides a list of BIAs found within PIFSC fisheries research areas (Baird

et al.,

2015).

Table 4—Biologically Important Areas Within PIFSC Research Areas

BIA name

Species

BIA type

Time of year

Size (km

2

)

HAWAIIAN ARCHIPELAGO RESEARCH AREA (HARA)

Kure Atoll and Midway Atoll

Spinner dolphin

Small and resident

Year-round

4,630

Pearl and Hermes Reef

Spinner dolphin

Small and resident

Year-round

2,099

Kauai and Ni'ihau

Spinner dolphin

Small and resident

Year-round

7,226

Ni'ihau and Kauai

Bottlenose dolphin

Small and resident

Year-round

2,764

Kauai, Ni'ihau, Maui, Hawai'i Islands

Humpback whale

Reproduction

February-March

5,846

Oahu and 4-Islands Area

Spinner dolphin

Small and resident

Year-round

14,616

Oahu

Bottlenose dolphin

Small and resident

Year-round

3,802

Oahu

Pantropical spotted dolphin

Small and resident

Year-round

1,048

Hawai'i Island to Ni'ihau Island

False killer whale

Small and resident

Year-round

5,430

4-Islands Area

Bottlenose dolphin

Small and resident

Year-round

10,622

Maui and Lanai

Pantropical spotted dolphin

Small and resident

Year-round

699

Hawai'i Island

Cuvier's beaked whale

Small and resident

Year-round

23,583

Hawai'i Island

Blainville's beaked whale

Small and resident

Year-round

7,442

Hawai'i Island

Bottlenose dolphin

Small and resident

Year-round

4,732

Hawai'i Island

Melon-headed whale

Small and resident

Year-round

1,753

Hawai'i Island

Short-finned pilot whale

Small and resident

Year-round

2,968

Hawai'i Island

Rough-toothed dolphin

Small and resident

Year-round

7,175

Hawai'i Island

Spinner dolphin

Small and resident

Year-round

9,469

Hawai'i Island

Pantropical spotted dolphin

Small and resident

Year-round

5,505

Hawai'i Island

Pygmy killer whale

Small and resident

Year-round

2,265

Hawai'i Island

Dwarf sperm whale

Small and resident

Year-round

2,675

Marine Mammal Hearing

Hearing is the most important sensory modality for marine mammals underwater, and exposure to anthropogenic sound can have deleterious effects. To appropriately assess the potential effects of exposure to sound, it is necessary to understand the frequency ranges marine mammals are able to hear. Current data indicate that not all marine mammal species have equal hearing capabilities (

e.g.,

Richardson

et al.,

1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall

et al.

(2007) recommended that marine mammals be divided into functional hearing groups based on directly measured or estimated hearing ranges on the basis of available behavioral response data, audiograms derived using auditory evoked potential techniques, anatomical modeling, and other data. Note that no direct measurements of hearing ability have been successfully completed for mysticetes (

i.e.,

low-frequency cetaceans).

Subsequently, NMFS (2018) described generalized hearing ranges for these marine mammal hearing groups. Generalized hearing ranges were chosen based on the approximately 65 dB threshold from the normalized composite audiograms, with an exception for lower limits for low-frequency cetaceans where the result was deemed to be biologically implausible and the lower bound of the low-frequency cetacean hearing range from Southall

et al.

(2007) retained. Marine mammal hearing groups and their associated hearing ranges are provided in Table 5.

Table 5—Marine Mammal Hearing Groups (NMFS, 2018)

Hearing group

Generalized hearing range *

Low-frequency (LF) cetaceans (baleen whales)

7 Hz to 35 kHz.

Mid-frequency (MF) cetaceans (dolphins, toothed whales, beaked whales, bottlenose whales)

150 Hz to 160 kHz.

High-frequency (HF) cetaceans (true porpoises,

Kogia,

river dolphins, cephalorhynchid,

Lagenorhynchus cruciger

&

L. australis

)

275 Hz to 160 kHz.

Phocid pinnipeds (PW) (underwater) (true seals)

50 Hz to 86 kHz.

Otariid pinnipeds (OW) (underwater) (sea lions and fur seals)

60 Hz to 39 kHz.

* Represents the generalized hearing range for the entire group as a composite (

i.e.,

all species within the group), where individual species' hearing ranges are typically not as broad. Generalized hearing range chosen based on ~65 dB threshold from normalized composite audiogram, with the exception for lower limits for LF cetaceans (Southall

et al.,

2007) and PW pinniped (approximation).

For more detail concerning these groups and associated frequency ranges, please see NMFS (2018) for a review of available information. Twenty-six marine mammal species (25 cetacean species and one phocid pinniped) have the potential to co-occur with PIFSC research activities—please refer to Table 3. Of the 25 cetacean species that may be present, six are classified as low-frequency cetaceans, 17 are classified as mid-frequency cetaceans, and two are classified as high-frequency cetaceans.

Potential Effects of the Specified Activity on Marine Mammals and Their Habitat

This section includes a summary and discussion of the ways that components of the specified activity (

e.g.,

gear deployment, use of active acoustic sources, visual disturbance) may impact marine mammals and their habitat. The “Estimated Take” section later in this document includes a quantitative analysis of the number of individuals that are expected to be taken by this activity. The “Negligible Impact Analysis and Determination” section considers the content of this section and the material it references, the “Estimated Take” section, and the “Proposed Mitigation” section, to draw conclusions regarding the likely impacts of these activities on the reproductive success or survivorship of individuals and how those impacts on individuals are likely to impact marine mammal species or stocks. In the following discussion, we consider potential effects to marine mammals from ship strike, physical interaction with the gear types described previously, use of active acoustic sources, and visual disturbance of pinnipeds.

Ship Strike

Vessel collisions with marine mammals, or ship strikes, can result in death or serious injury of the animal. Wounds resulting from ship strike may include massive trauma, hemorrhaging, broken bones, or propeller lacerations (Knowlton and Kraus, 2001). An animal at the surface may be struck directly by a vessel, a surfacing animal may hit the bottom of a vessel, or an animal just below the surface may be cut by a vessel's propeller. Animals may survive superficial strikes. These interactions are typically associated with large whales, which on occasion, are fatally struck by large commercial ships. Although smaller cetaceans or pinnipeds are more maneuverable in relation to large vessels than are large whales, they may also be susceptible to ship strike. The severity of injuries typically depends on the size and speed of the vessel, with the probability of death or serious injury increasing as vessel speed increases (Knowlton and Kraus, 2001; Laist

et al.,

2001; Vanderlaan and Taggart, 2007; Conn and Silber, 2013). Impact forces increase with speed, as does the probability of a strike at a given distance due to reduced detection and reaction time (Silber

et al.,

2010; Gende

et al.,

2011).

Pace and Silber (2005) found that the probability of death or serious injury by ship strike increased rapidly with increasing vessel speed. Specifically, the predicted probability of serious

injury or death increased from 45 to 75 percent as vessel speed increased from 10 to 14 kt, and exceeded 90 percent at 17 kt. Higher speeds during collisions result in greater force of impact, but higher speeds also appear to increase the chance of severe injuries or death through increased likelihood of collision by pulling whales toward the vessel (Clyne, 1999; Knowlton

et al.,

1995). In a separate study, Vanderlaan and Taggart (2007) analyzed the probability of lethal mortality of large whales at a given speed, showing that the greatest rate of change in the probability of a lethal injury to a large whale as a function of vessel speed occurs between 8.6 and 15 kt. The chances of a lethal injury decline from approximately 80 percent at 15 kt to approximately 20 percent at 8.6 kt. At speeds below 11.8 kt, the chances of lethal injury drop below fifty percent, while the probability asymptotically increases toward one hundred percent above 15 kt.

In an effort to reduce the number and severity of strikes of the endangered North Atlantic right whale (

Eubalaena glacialis

), NMFS implemented speed restrictions in 2008 (73 FR 60173; October 10, 2008). These restrictions require that vessels greater than or equal to 65 ft (19.8 m) in length travel at less than or equal to 10 kt near key port entrances and in certain areas of right whale aggregation along the U.S. eastern seaboard. Conn and Silber (2013) estimated that these restrictions reduced total ship strike mortality risk levels by 80 to 90 percent.

For vessels used in PIFSC research activities, transit speeds average 10 kt (but vary from 6-14 kt), while vessel speed during active sampling with towed gear is typically only 2-4 kt. At sampling speeds, both the possibility of striking a marine mammal and the possibility of a strike resulting in serious injury or mortality are discountable. Ship strikes, as analyzed in the studies cited above, generally involve commercial shipping, which is much more common in both space and time than is research activity. Jensen and Silber (2004) summarized ship strikes of large whales worldwide from 1975-2003 and found that most collisions occurred in the open ocean and involved large vessels (

e.g.,

commercial shipping). Commercial fishing vessels, which are similar in size to some of the ships used by PIFSC, were responsible for three percent of recorded collisions, while only one such incident (0.75 percent of recorded ship strikes) was reported for a research vessel during that time period.

It is possible for ship strikes to occur while traveling at slow speeds. For example, a hydrographic survey vessel traveling at low speed (5.5 kt) while conducting mapping surveys off the central California coast struck and killed a blue whale in 2009. The State of California determined that the whale had suddenly and unexpectedly surfaced beneath the hull, with the result that the propeller severed the whale's vertebrae, and that this was an unavoidable event. The strike represents the only such incident in approximately 540,000 hours of similar coastal mapping activity (

p

= 1.9 × 10

−6

; 95% CI = 0−5.5 × 10

−6

; NMFS, 2013). In addition, a research vessel reported a fatal strike in 2011 of a dolphin in the Atlantic, demonstrating that it is possible for strikes involving smaller cetaceans or pinnipeds to occur. In that case, the incident report indicated that an animal apparently was struck by the vessel's propeller as it was intentionally swimming near the vessel. While indicative of the type of unusual events that cannot be ruled out, neither of these instances represents a circumstance that would be considered reasonably foreseeable or that would be considered preventable.

Although the likelihood of vessels associated with research surveys striking a marine mammal are low, this rule requires a robust ship strike avoidance protocol (see “Proposed Mitigation”), which we believe eliminates any foreseeable risk of ship strike. We anticipate that vessel collisions involving PIFSC research vessels, while not impossible, represent unlikely, unpredictable events. Furthermore, PIFSC has never reported a ship strike associated with fisheries research activities conducted or funded by the PIFSC. Given the proposed mitigation measures such as the presence of bridge crew watching for obstacles at all times (including marine mammals), the presence of marine mammal observers on some surveys, (see “Proposed Mitigation”) as well as the small number of research cruises relative to commercial ship traffic, we believe that the possibility of ship strike is discountable. Moreover, given the relatively slow speeds at which PIFSC research vessels travel during sampling activities and during transit, even if a marine mammal is struck, it would not likely result in serious injury or mortality (Knowlton and Kraus, 2001; Laist

et al.,

2001; Vanderlaan and Taggart, 2007; Conn and Silber, 2013). No incidental take resulting from ship strike is anticipated.

Research Gear

The types of research gear used by PIFSC were described previously under “Detailed Description of Activity.” Here, we broadly categorize the gear as either (1) extremely unlikely to result in marine mammal interactions, or (2) gear that may result in marine mammal interactions. Former category is not considered further, while those in the latter category is discussed below. Marine mammal interaction is most likely for trawls and longlines.

Trawl nets and longlines deployed by PIFSC are similar to gear used in various commercial fisheries. There are documented occurrences of and potential for marine mammal interaction with these gear types via physical contact such as capture or entanglement. Read

et al.

(2006) estimated marine mammal bycatch in U.S. fisheries from 1990-99 and derived an estimate of global marine mammal bycatch by expanding U.S. bycatch estimates using data on fleet composition from the United Nations Food and Agriculture Organization (FAO). Although most U.S. bycatch for both cetaceans (84 percent) and pinnipeds (98 percent) occurred in gillnets (a type of gear not used by PIFSC), global marine mammal bycatch in trawls and longlines is likely substantial given that total global bycatch may be hundreds of thousands of individuals per year (Read

et al.,

2006). In addition, global bycatch via longline has likely increased, as longlines are currently the most common method of capturing swordfish and tuna since the U.N. banned the use of high seas driftnets over 2.5 km long in 1991 (high seas driftnets were previously often 40-60 km long) (Read, 2008; FAO, 2001).

Marine mammals are intelligent and inquisitive—when their pursuit of prey coincides with human pursuit of the same resources, physical interaction with fishing gear may occur (

e.g.,

Beverton, 1985). Fishermen and marine mammals are both drawn to areas of high prey density, and certain fishing activities may further attract marine mammals by providing food (

e.g.,

bait, captured fish, bycatch discards) or by otherwise making it easier for animals to feed on a concentrated food source. Similarly, near-surface foraging opportunities may present an advantage for marine mammals by negating the need for energetically expensive deep foraging dives (Hamer and Goldsworthy, 2006). Trawling, for example, can make available previously unexploited food resources by gathering prey that may otherwise be too fast or deep for normal

predation, or may concentrate calories in an otherwise patchy landscape (Fertl and Leatherwood, 1997). Pilot whales, which are generally considered to be teuthophagous (

i.e.,

feeding primarily on squid), were commonly observed in association with Atlantic mackerel (

Scomber scombrus

) trawl fisheries from 1977-88 in the northeast U.S. EEZ (Waring

et al.,

1990). Not surprisingly, stomach contents of captured whales contained high proportions of mackerel (68 percent of non-trace food items), indicating that the ready availability of a novel, concentrated, high-calorie prey item resulted in changed dietary composition (Read, 1994).

These interactions can result in injury or death for the animal(s) involved and/or damage to fishing gear. Coastal animals, including various pinnipeds, bottlenose dolphins, and harbor porpoises, are perhaps the most vulnerable to these interactions with set or passive fishing gear (

e.g.,

gillnets, traps) the most likely culprit (

e.g.,

Beverton, 1985; Barlow

et al.,

1994; Read

et al.,

2006; Byrd

et al.,

2014; Lewison

et al.,

2014). However, interactions with trawls and longlines may also occur and therefore also warrant mitigation measures (NMFS, 2017). Although all marine mammal species have some risk for interaction with fishing gear (

e.g.,

Northridge, 1984), the extent of interactions is likely dependent on the biology, ecology, and behavior of the species involved and the type, location, and nature of the fishery.

Trawl Nets

—As described previously, trawl nets are towed nets (

i.e.,

active fishing) consisting of a cone-shaped net with a codend or bag for collecting the fish and can be designed to fish at the bottom, surface, or any other depth in the water column. Here we refer to bottom trawls and pelagic trawls (midwater or surface,

i.e.,

any net not designed to tend the bottom while fishing). Trawl nets can capture or entangle marine mammals. This may occur in bottom trawls, presumably when marine mammals feed on fish caught therein, and in pelagic trawls which may or may not be coincident with marine mammals feeding (Northridge, 1984).

Capture or entanglement may occur whenever marine mammals are swimming near the gear, intentionally (

e.g.,

foraging) or unintentionally (

e.g.,

migrating), and any animal captured in a net is at significant risk of drowning unless quickly freed. Netting and tow lines (also called lazy lines) may also entangle around the a marine mammal's head, body, flukes, pectoral fins, or dorsal fin. Interaction that does not result in the immediate death of the animal by drowning can cause injury (

i.e.,

Level A harassment) or serious injury. Constricting lines wrapped around the animal can immobilize the animal or injure by cutting into or through blubber, muscles and bone (

i.e.,

penetrating injuries) or constricting blood flow to or severing appendages. Immobilization of the animal, if it does not result in immediate drowning, can cause internal injuries from prolonged stress and/or severe struggling and/or impede the animal's ability to feed (resulting in starvation or reduced fitness) (Andersen

et al.,

2008).

Marine mammal interactions with trawl nets, through capture or entanglement, are well-documented. Dolphins are known to attend operating nets in order to either benefit from disturbance of the bottom or to prey on discards or fish within the net. For example, Leatherwood (1975) reported that the most frequently observed feeding pattern for bottlenose dolphins in the Gulf of Mexico involved herds following working shrimp trawlers, apparently feeding on organisms stirred up from the benthos. Bearzi and di Sciara (1997) opportunistically investigated working trawlers in the Adriatic Sea from 1990-94 and found that ten percent were accompanied by foraging bottlenose dolphins. Pelagic trawls appear to have greater potential to capture cetaceans, because the nets may be towed at faster speeds, these trawls are more likely to target species that are important prey for marine mammals (

e.g.,

squid, mackerel), and because pelagic trawls often fish in deeper waters with potential for a more diverse assemblage of species (Hall

et al.,

2000).

Globally, at least 17 cetacean species are known to feed in association with trawlers and trawl nets have killed individuals of at least 25 species, including several large whales, porpoises, and a variety of delphinids (Perez, 2006; Young and Iudicello, 2007; Karpouzli and Leaper, 2004; Hall

et al.,

2000; Fertl and Leatherwood, 1997; Northridge, 1991; Song

et al.,

2010). Trawls have killed at least eighteen species of seals and sea lions (Wickens, 1995; Perez, 2006; Zeeberg

et al.,

2006). Records of direct interaction between trawl nets and marine mammals (both cetaceans and pinnipeds) exist where trawling and animals co-occur. A lack of recorded interactions where animals are known to be present may indicate simply that trawling is absent or are an insignificant component of fisheries in that region or that interactions were not observed, recorded, or reported.

In evaluating risk relative to a specific fishery (or comparable research survey), one must consider the size of the net as well as frequency, timing, and location of deployment. These considerations inform determinations of whether marine mammal take is likely. Other NMFS science centers have records of marine mammal take from bottom, surface, and midwater trawl nets. However, PIFSC has no history of marine mammal take from trawl nets used during PIFSC fisheries and ecosystem surveys.

Longlines

—Longlines are a passive fishing technique of consisting of strings of baited hooks that are either anchored to the bottom (targeting groundfish), or are free-floating (targeting pelagic species). PIFSC does not utilize free-floating longlines. Any longline generally consists of a mainline from which leader lines (gangions) with baited hooks branch off at a specified interval. Bottom longlines may be of monofilament or multifilament natural or synthetic lines.

The longline is left to passively fish (

i.e,

soak) for a set period of time before the vessel returns to retrieve the gear. Two or more floats act as visual markers to facilitate gear retrieval. Longlines may also utilize radio beacons to assist gear detection. Radio beacons are particularly import for pelagic longlines that may drift a significant distance from the deployment location.

Marine mammals may be hooked or entangled in longline gear, with interactions potentially resulting in death due to drowning, strangulation, severing of carotid arteries or the esophagus, infection, an inability to evade predators, or starvation due to an inability to catch prey (Hofmeyr

et al.,

2002), although it is more likely that marine mammals will survive if they can reach the surface to breathe. Injuries, including serious injury, may consist of lacerations and puncture wounds. Animals may attempt to depredate on either bait or catch, with subsequent hooking, or may become accidentally entangled. As described for trawls, entanglement can lead to constricting lines wrapped around the animals and/or immobilization, and even if entangling materials are removed the wounds caused may continue to weaken the animal or allow further infection (Hofmeyr

et al.,

2002). Large whales may become entangled in a longline and then break free with a portion of gear trailing, resulting in alteration of swimming energetics due to drag and ultimate loss of fitness and potential mortality (Andersen

et al.,

2008). Weight of the gear can cause entangling lines to further constrict and further injure the animal. Hooking injuries and ingested gear are most

common in small cetaceans and pinnipeds, but have been observed in large cetaceans (

e.g.,

sperm whales). The severity of the injury depends on the species, whether ingested gear includes hooks, whether the gear works its way into the gastrointestinal (GI) tract, whether the gear penetrates the GI lining, and the location of the hooking (

e.g.,

embedded in the animal's stomach or other internal body parts) (Andersen

et al.,

2008). Bottom longlines pose less of a threat to marine mammals due to their deployment on the ocean bottom but can still result in entanglement in buoy lines or hooking as the line is either deployed or retrieved. The rate of interaction between longline fisheries and marine mammals depends on the degree of overlap between longline effort and species distribution, hook style and size, type of bait and target catch, and fishing practices (such as setting/hauling during the day or at night).

As was noted for trawl nets, many species of cetaceans and pinnipeds are documented to have been killed by longlines, including several large whales, porpoises, a variety of delphinids, seals, and sea lions (Perez, 2006; Young and Iudicello, 2007; Northridge, 1984, 1991; Wickens, 1995). Records of direct interaction between longlines and marine mammals (both cetaceans and pinnipeds) exist where longline fishing and animals co-occur. A lack of recorded interactions where animals are known to be present may indicate simply that longlining is absent or an insignificant component of fisheries in that region or that interactions were not observed, recorded, or reported.

In evaluating risk relative to a specific fishery (or research survey), one must consider the length of the line and number of hooks deployed as well as frequency, timing, and location of deployment. These considerations inform determinations of whether interaction with marine mammals is likely. PIFSC has not recorded marine mammal interactions or takes with any longline survey. While a lack of historical interactions does not in and of itself indicate that future interactions are unlikely, we believe that the historical record, considered in context with the frequency and timing of these activities, as well as mitigation measures employed indicate that future marine mammal interactions with these gears would be uncommon.

Other research gear

—PIFSC conducts a variety of instrument deployments and insular fish abundance surveys between 50m and 600m and bottomfish essential fish habitat (EFH) surveys between 100-400m (see Table 1.1 in PIFSC's application) using gear similar to that used in a variety of commercial fisheries. Thus such research gear has the potential for entangling marine mammals surfacing from dives. Such “instrument deployments” include aMOUSS, BotCam, BRUVS deployed from a vessel and connected to the surface with a line to a float or vessel; environmental sampling instruments deployed by line such as CTD; baited or unbaited bottom traps such as lobster traps and fish traps deployed from a vessel and connected to the surface with line to a float.

All other gears used in PIFSC fisheries research (

e.g.,

various plankton nets, CTDs, remotely operated vehicles (ROVs)) do not have the expected potential for marine mammal interactions. PIFSC has no record of marine mammal interaction or takes from these types of gear. Specifically, we consider CTDs, ROVs, small surface trawls, plankton nets, other small nets, camera traps, dredges, and vertically deployed or towed imaging systems to be no-impact gear types. Unlike trawl nets, seine nets, and longline gear, which are used in both scientific research and commercial fishing applications, these other gears are not considered similar or analogous to any commercial fishing gear and are not designed to capture any commercially salable species, or to collect any sort of sample in large quantities. They are not considered to have the potential to take marine mammals primarily because of their design or how they are deployed. For example, CTDs are typically deployed in a vertical cast on a cable and have no loose lines or other entanglement hazards. A Bongo net is typically deployed on a cable, whereas neuston nets (these may be plankton nets or small trawls) are often deployed in the upper one meter of the water column; either net type has very small size (

e.g.,

two bongo nets of 0.5 m

2

each or a neuston net of approximately 2 m

2

) and no trailing lines to present an entanglement risk. These other gear types are not considered further in this document.

Acoustic Effects

Detailed descriptions of the potential effects of PIFSC's use of acoustic sources are provided in other

Federal Register

notices for incidental take regulations issued to other NMFS Science Centers (

e.g.,

the “Acoustic Effects” section of the proposed rule for the taking of marine mammals incidental to NMFS Alaska Fisheries Science Center fisheries research (83 FR 37660; August 1, 2018) and the “Potential Effects of Underwater Sound” section of the proposed rule for the taking of marine mammals incidental to NMFS Southeast Fisheries Science Center research (84 FR 6603; February 27, 2019)). No significant new information is available, and those discussions provide the necessary adequate and relevant information regarding the potential effects of PIFSC's specified activity on marine mammals and their habitat. Therefore, we refer the reader to those documents rather than repeating the information here.

Exposure to sound through the use of active acoustic systems for research purposes may result in Level B harassment. However, as detailed in the previously referenced discussions, Level A harassment in the form of permanent threshold shift (PTS) is extremely unlikely to occur, and we consider such effects discountable. With specific reference to Level B harassment that may occur as a result of acoustic exposure, we note that the analytical methods described in the incidental take regulations for other NMFS Science Centers are retained here. However, the state of science with regard to our understanding of the likely potential effects of the use of systems like those used by PIFSC has advanced in recent years, as have readily available approaches to estimating the acoustic footprints of such sources, with the result that we view this analysis as highly conservative. Although more recent literature provides documentation of marine mammal responses to the use of these and similar acoustic systems (

e.g.,

Cholewiak

et al.,

2017; Quick

et al.,

2017; Varghese

et al.,

2020), the described responses do not generally comport with the degree of severity that should be associated with Level B harassment, as defined by the MMPA. We retain the analytical approach described in the incidental take regulations for other NMFS Science Centers for consistency with existing analyses and for purposes of efficiency here, and consider this acceptable because the approach provides a conservative estimate of potential incidents of Level B harassment (see “Estimated Take” section of this document). In summary, while we propose to authorize the amount of take by Level B harassment indicated in the “Estimated Take” section, and consider these potential takings at face value in our negligible impact analysis, it is uncertain whether use of these acoustic systems are likely to cause take at all, much less at the estimated levels.

Potential Effects of Visual Disturbance

Hawaiian monk seals occur in the HARA and WCPRA. Hawaiian monk seals use numerous sites in the MHI and the NWHI to haul out (

e.g.,

sandy beaches, rocky outcroppings, exposed reefs). Here, the physical presence and sounds of researchers walking by or passing nearby in small boats may disturb animals present. PIFSC expects some of these animals will exhibit a behavioral response to the visual stimuli (

e.g.,

including alert behavior, movement, vocalizing, or flushing). NMFS does not consider the lesser reactions (

e.g.,

alert behavior) to constitute harassment. These events are expected to be infrequent and cause only a temporary disturbance on the order of minutes. Monitoring results from other activities involving the disturbance of pinnipeds and relevant studies of pinniped populations that experience more regular vessel disturbance indicate that individually significant or population level impacts are unlikely to occur (

e.g.,

Henry and Hammil, 2001).

In areas where disturbance of haulouts due to periodic human activity (

e.g.,

researchers approaching on foot, passage of small vessels, maintenance activity) occurs, monitoring results have generally indicated that pinnipeds typically move or flush from the haulout in response to human presence or visual disturbance, although some individuals typically remain hauledout (

e.g.,

SCWA, 2012). Upon the occurrence of low-severity disturbance (

i.e.,

the approach of a vessel or person as opposed to an explosion or sonic boom), pinnipeds typically exhibit a continuum of responses, beginning with alert movements (

e.g.,

raising the head), which may then escalate to movement away from the stimulus and possible flushing into the water. Flushed pinnipeds typically re-occupy the haulout within minutes to hours of the stimulus (Acevedo-Gutierrez and Johnson 2007).

In a popular tourism area of the Pacific Northwest where human disturbances occurred frequently, past studies observed stable populations of seals over a twenty-year period (Calambokidis

et al.,

1991). Despite high levels of seasonal disturbance by tourists using both motorized and non-motorized vessels, Calambokidis

et al.

(1991) observed an increase in site use (pup rearing) and classified this area as one of the most important pupping sites for seals in the region. Another study observed an increase in seal vigilance when vessels passed the haulout site, but then vigilance relaxed within ten minutes of the vessels' passing (Fox, 2008). If vessels passed frequently within a short time period (

e.g.,

24 hours), a reduction in the total number of seals present was also observed (Fox, 2008).

Level A harassment, serious injury, or mortality could likely only occur as a result of trampling in a stampede (a potentially dangerous occurrence in which large numbers of animals succumb to mass panic and rush away from a stimulus) or abandonment of pups. Pups could be present at times during PIFSC research effort, but PIFSC researchers take precautions to minimize disturbance and prevent any possibility of stampedes, including choosing travel routes as far away from hauledout pinnipeds as possible and by moving sample site locations to avoid consistent haulout areas. In addition, Hawaiian monk seals do not typically haul out in large groups where stampedes would be of concern.

Disturbance of pinnipeds caused by PIFSC survey activities would be expected to last for only short periods of time, separated by significant amounts of time in which no disturbance occurred. Because such disturbance is sporadic, rather than chronic, and of low intensity, individual marine mammals are unlikely to incur any detrimental impacts to vital rates or ability to forage and, thus, loss of fitness. Correspondingly, even local populations, much less the overall stock of animals, are extremely unlikely to accrue any significantly detrimental impacts.

Anticipated Effects on Marine Mammal Habitat

Effects to Prey

—In addition to direct, or operational, interactions between fishing gear and marine mammals, indirect (

i.e.,

biological or ecological) interactions occur as well, in which marine mammals and fisheries both utilize the same resource, potentially resulting in competition that may be mutually disadvantageous (

e.g.,

Northridge, 1984; Beddington

et al.,

1985; Wickens, 1995). Marine mammal prey varies by species, season, and location and, for some marine mammals, is not well documented. PIFSC fisheries research removals of species commonly utilized by marine mammals are relatively low. Prey of sei whales and blue whales are primarily zooplankton, which are targeted by PIFSC fisheries research with collection only on the order of liters, so the likelihood of research activities changing prey availability is low and impact negligible to none. Humpback whales do not feed within the PIFSC region of fisheries research, so there is no effect (Herman

et al.,

2007). PIFSC fisheries research activities may affect sperm whale prey (squid), but this is expected to be minor due to the insignificant amount of squid removed through fisheries research (

i.e.,

hundreds of pounds). There may be some minor overlap between the RAMP survey removals of a variety of reef fishes and the Insular Fish Abundance Estimation Comparison Surveys. By example, in the main Hawaiian Islands, the majority of sampling for these surveys is at the periphery of monk seal foraging habitat and is a tiny fraction of what is taken by monk seals or by apex predatory fish or non-commercial fisheries (Sprague

et al.

2013, Kobayashi and Kawamoto 1995). In the case of false killer whale consumption of tunas, mahi, and ono, there may be some minor overlap with fisheries research removals in the pelagic longline research. However, here the removal by PIFSC fisheries research, regardless of season and location is minor relative to that taken through commercial fisheries. For example, commercial fisheries catches for most pelagic species typically range from the hundreds to thousands of metric tons, whereas the catch in similar fisheries research activities would only occasionally range as high as hundreds to thousands of pounds in any particular year (see Sections 4.2.3 and 4.3.3 of the PIFSC EA for more information on fish catch during research surveys and commercial harvest).

Research catches are also distributed over a wide area because of the random sampling design covering large sample areas. Fish removals by research are therefore highly localized and unlikely to affect the spatial concentrations and availability of prey for any marine mammal species. The overall effect of research catches on marine mammals through competition for prey may therefore be considered insignificant for all species.

Acoustic Habitat

—Acoustic habitat is the soundscape—which encompasses all of the sound present in a particular location and time, as a whole—when considered from the perspective of the animals experiencing it. Animals produce sound for, or listen for sounds produced by, conspecifics (communication during feeding, mating, and other social activities), other animals (finding prey or avoiding predators), and the physical environment (finding suitable habitats, navigating). Together, sounds made by animals and the geophysical environment (

e.g.,

produced by earthquakes, lightning, wind, rain,

waves) make up the natural contributions to the total acoustics of a place. These acoustic conditions, termed acoustic habitat, are one attribute of an animal's total habitat.

Soundscapes are also defined by, and acoustic habitat influenced by, the total contribution of anthropogenic sound. This may include incidental emissions from sources such as vessel traffic, or may be intentionally introduced to the marine environment for data acquisition purposes (as in the PIFSC's use of active acoustic sources). Anthropogenic noise varies widely in its frequency content, duration, and loudness and these characteristics greatly influence the potential habitat-mediated effects to marine mammals (please also see the discussion on masking in the Acoustic Effects” section of the proposed rule for the taking of marine mammals incidental to NMFS Alaska Fisheries Science Center fisheries research (83 FR 37660; August 1, 2018)), which may range from local effects for brief periods of time to chronic effects over large areas and for long durations. Depending on the extent of effects to habitat, animals may alter their communications signals (thereby potentially expending additional energy) or miss acoustic cues (either conspecific or adventitious). For more detail on these concepts see,

e.g.,

Barber

et al.,

2010; Pijanowski

et al.,

2011; Francis and Barber, 2013; Lillis

et al.,

2014.

Problems arising from a failure to detect cues are more likely to occur when noise stimuli are chronic and overlap with biologically relevant cues used for communication, orientation, and predator/prey detection (Francis and Barber, 2013). As described above (“Acoustic Effects”), the signals emitted by PIFSC active acoustic sources are generally high frequency, of short duration, and transient. These factors mean that the signals will attenuate rapidly (not travel over great distances), may not be perceived or affect perception even when animals are in the vicinity, and would not be considered chronic in any given location. PIFSC use of these sources is widely dispersed in both space and time. In conjunction with the prior factors, this means that it is highly unlikely that PIFSC use of these sources would, on their own, have any appreciable effect on acoustic habitat. Sounds emitted by PIFSC vessels would be of lower frequency and continuous, but would also be widely dispersed in both space and time. PIFSC vessel traffic—including both sound from the vessel itself and from the active acoustic sources—is of very low density compared to commercial shipping traffic or commercial fishing vessels and would therefore represent an insignificant incremental increase in the total amount of anthropogenic sound input to the marine environment.

Physical Habitat

—PIFSC conducts some bottom trawling, which may physically damage seafloor habitat. In addition, PIFSC fishery research activities and funded fishery research activities use bottom contact fishing gear, including deep-set longline, lobster traps, and settlement traps. These fishing gears contact the seafloor and may cause physical damage but the impacts are localized and minimal as this type of gear is fixed in position rather than towed across the sea floor. Physical damage may include furrowing and smoothing of the seafloor as well as the displacement of rocks and boulders, and such damage can increase with multiple contacts in the same area (Schwinghamer

et al.,

1998; Kaiser

et al.,

2002; Malik and Mayer, 2007; NRC, 2002). The effects of bottom contact gear differ in each type of benthic environment. In sandy habitats with strong currents, the furrows created by mobile bottom contact gear quickly begin to erode because lighter weight sand at the edges of furrows can be easily moved by water back towards the center of the furrow (NRC, 2002). Duration of effects in these environments therefore tend to be very short because the terrain and associated organisms are accustomed to natural disturbance. By contrast, the physical features of more stable hard bottom habitats are less susceptible to disturbance, but once damaged or removed by fishing gear, the organisms that grow on gravel, cobbles, and boulders can take years to recover, especially in deeper water where there is less natural disturbance (NRC, 2002). However, the area of benthic habitat affected by PIFSC research each year would be a very small fraction of total area of benthic habitat in the four research areas and effects are not expected to occur in areas of particular importance.

Damage to seafloor habitat may also harm infauna and epifauna (

i.e.,

animals that live in or on the seafloor or on structures on the seafloor), including corals (Schwinghamer

et al.,

1998; Collie

et al.,

2000; Stevenson

et al.,

2004). In general, recovery from biological damage varies based on the type of fishing gear used, the type of seafloor surface (

i.e.,

mud, sand, gravel, mixed substrate), and the level of repeated disturbances. Recovery timelines of 1-18 months are expected. However, repeated disturbance of an area can prolong the recovery time (Stevenson

et al.,

2004), and recovery of corals may take significantly longer than 18 months.

The Deep Coral and Sponge Research Survey collect small pieces of coral for DNA samples, voucher specimens, and paleoclimate samples. The combined sampling of these studies amounts to about 5.5 pounds/year. Together, these coral samples comprise a small percentage of the total population of coral colonies (see Section 4.2.7 of the PIFSC EA). The RAMP Survey collects up to 500 samples per year of corals (including ESA-listed species), coral products, algae and algal products, and sessile invertebrates. The NMFS Pacific Islands Regional Office has issued a Biological Opinion concluding that PIFSC surveys are not likely to jeopardize the continued existence of any coral species taken.

As described in the preceding, the potential for PIFSC research to affect the availability of prey to marine mammals or to meaningfully impact the quality of physical or acoustic habitat is considered to be insignificant for all species. Effects to marine mammal habitat will not be discussed further in this document.

Estimated Take

This section provides an estimate of the number of incidental takes proposed for authorization. The estimated take informs NMFS' determination of whether the number of takes are “small” and the negligible impact determination.

Except with respect to certain activities not pertinent here, the MMPA defines “harassment” as: Any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild (Level A harassment); or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering (Level B harassment).

Take of marine mammals incidental to PIFSC research activities could occur as a result of (1) injury or mortality due to gear interaction (Level A harassment, serious injury, or mortality); (2) behavioral disturbance resulting from the use of active acoustic sources (Level B harassment only); or (3) behavioral disturbance of pinnipeds resulting from incidental approach of researchers and research vessels (Level B harassment only). Below we describe how the potential take is estimated.

Estimated Take Due to Gear Interaction

The use of historical interactions as a basis to estimate future take of marine mammals in fisheries research gear has been utilized in the LOA applications and rules of other NMFS Fisheries Science Centers (

e.g.,

Southwest (SWFSC), Northwest (NWFSC)). However, because PIFSC has no history of marine mammal take in any of the gear used during its fisheries and ecosystem research, additional factors must be considered. Instead, NMFS used information from commercial fisheries, other NMFS Fisheries Science Centers operations, and published take as described below.

NMFS believes it is appropriate to include estimates for future incidental takes of a number of species that have not been taken by PIFSC historically, but inhabit the same areas and show similar types of behaviors and vulnerabilities to gear used by other NMFS Fisheries Science Centers and used in commercial fisheries (based on the 2019 List of Fisheries (LOF), see

https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-protection-act-list-fisheries

). A number of factors were taken into account to determine whether a species may have a similar vulnerability to certain types of gear as species taken in commercial gear and research gear elsewhere (

e.g.,

distribution, density, abundance, behavior, feeding ecology, travel in groups, and common association with other species historically taken in commercial gear or other Fisheries Science Centers). While such take could potentially occur, NMFS believes that any occurrences would likely be rare given that no such take in PIFSC research has occurred (despite many years of the same or similar surveys occurring). Moreover, marine mammal behavioral and ecological characteristics reduce the risk of incidental take from research gear, and the required mitigation measures reduce the risk of incidental take.

As background to the process of determining which species not historically taken may have sufficient vulnerability to capture in PIFSC gear to justify inclusion in these proposed regulations, we note that the PIFSC is NMFS's research arm in the central and western Pacific Ocean and may be considered as a leading source of expert knowledge regarding marine mammals (

e.g.,

behavior, abundance, density) in the areas where they operate. The species for which the take request was formulated were selected by the PIFSC, and we have concurred with these decisions.

While PIFSC has not historically taken marine mammal species in its longline gear, it is well documented that some species potentially encountered during PIFSC surveys a

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