# Takes of Marine Mammals During Specified Activities; Confined Blasting Operations by the U.S. Army Corps of Engineers During the Port of Miami Construction Project in Miami, FL

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URL: https://www.frixlaw.com/law-library/documents/fr%3A2012-19460

## Record

- **Collection:** Federal Register
- **Document type:** Notice
- **Published:** August 15, 2012
- **Citation:** 77 FR 49278

## Text

DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XA628
Takes of Marine Mammals During Specified Activities; Confined Blasting Operations by the U.S. Army Corps of Engineers During the Port of Miami Construction Project in Miami, FL

AGENCY:

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

ACTION:

Notice; issuance of an Incidental Take Authorization (ITA).

SUMMARY:

In accordance with the Marine Mammal Protection Act (MMPA) regulation, notification is hereby given that NMFS has issued an Incidental Harassment Authorization (IHA) to the U.S. Army Corps of Engineers (ACOE) take small numbers of marine mammals, by Level B harassment, incidental to confined blasting operations in the Port of Miami in Miami, Florida.

DATES:

Effective March 15, 2013 through March 14, 2014.

ADDRESSES:

A copy of the IHA and the application are available by writing to P. Michael Payne, Chief, Permits and Conservation Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910 or by telephoning the contacts listed here.

An electronic copy of the IHA application containing a list of the references used in this document may be obtained by writing to the above address, telephoning the contact listed here (see
FOR FURTHER INFORMATION CONTACT
) or visiting the internet at:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.

This project was previously evaluated by the ACOE under an Environmental Impact Statement (EIS) and a Record of Decision (ROD) for the project was signed on May 22, 2006, which is also available at the same internet address. Documents cited in this notice may be viewed, by appointment, during regular business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT:

Howard Goldstein or Jolie Harrison, Office of Protected Resources, NMFS, 301-427-8401.

SUPPLEMENTARY INFORMATION:

Background

Section 101(a)(5)(D) of the MMPA (16 U.S.C. 1361 (a)(5)(D)) directs the Secretary of Commerce (Secretary) to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals of a species or population stock, by United States citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.

Authorization for the incidental taking of small numbers of marine mammals shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s), and will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses (where relevant). The authorization must set forth the permissible methods of taking, other means of effecting the least practicable adverse impact on the species or stock and its habitat, and requirements pertaining to the mitigation, monitoring and reporting of such takings. 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.”

Section 101(a)(5)(D) of the MMPA established an expedited process by which citizens of the United States can apply for an authorization to incidentally take small numbers of marine mammals by harassment. Section 101(a)(5)(D) of the MMPA establishes a 45-day time limit for NMFS' review of an application followed by a 30-day public notice and comment period on any proposed authorizations for the incidental harassment of small number of marine mammals. Within 45 days of the close of the public comment period, NMFS must either issue or deny the authorization.

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].

16 U.S.C. 1362(18).

Summary of Request

On May 17, 2011, NMFS received a letter from the ACOE, requesting an IHA. The requested IHA would authorize the take, by Level B (behavioral) harassment, of small numbers of Atlantic bottlenose dolphins (
Tursiops truncatus
) incidental to confined blasting operations in the Miami Harbor, Port of Miami, in Miami-Dade County, Florida. The IHA application was considered adequate and complete on September 9, 2011. The ACOE plans to conduct four components as part of the project in Miami Harbor (see Figure 1 of the ACOE's IHA application for a map and more details). These components are:

(1) The widening of Cut 1 and deepening of Cut 1 and Cut 2;

(2) Adding a turn widener and deepening at the southern intersection of Cut 3 within Fisherman's Channel;

(3) Widening and deepening the Fisher Island Turning Basin; and

(4) Expanding the Federal Channel and Port of Miami berthing areas in Fisherman's Channel and the Lummus Island Turning Basin.

The construction will likely be completed using a combination of mechanical dredge (
i.e.,
a clamshell or backhoe), cutterhead dredge, and rock pre-treatment by confined blasting. The dredging will remove approximately 5,000,000 cubic yards (3,822,774.3 cubic meters [m
3
]) of material from the harbor. Material removed from the dredging will be placed in Miami Harbor Ocean Dredged Material Disposal Site, or used to construct seagrass and reef mitigation projects.

The confined blasting is planned to take place beginning during the fall/winter of 2012 (November, 2012), and is expected to take up to 24 months in Miami, Florida. Additional information on the construction project is contained in the application, which is available upon request (see
ADDRESSES
). Confined blasting means that the shots would be “confined” in the rock with stemming that prevents the explosive energy from going upward from the hole into the water column, and forces it to go laterally into the surrounding rock. In confined blasting, each charge is placed in a hole drilled in the rock approximately 5 to 10 feet deep; depending on how much rock needs to be broken and the intended project depth. The hole is then capped with an inert material, such as crushed rock. A charge is the total weight of the explosives to be detonated during a blast. This can also be broken down into the weight of the individual delays. This process is referred to as “stemming the

hole” (see Figure 6 and 7 of the ACOE's application).

Description of the Specified Activities

The ACOE plans to deepen and widen the Federal channels at Miami Harbor, Port of Miami, in Miami-Dade County, Florida. The recommended plan (Alternative 2 of the Environmental Impact Statement [EIS]) includes four components:

(1) Widen the seaward portion of Cut 1 from 500 to 800 feet (ft) (152.4 to 243.8 meters [m]) and deepen Cut 1 and Cut 2 from a project depth of −44 to −52 ft (13.4 to 15.9 m);

(2) Add a turn widener at the southern intersection of Cut 3 within Fisherman's Channel and deepen to a project depth of −50 ft (−15.2 m);

(3) Increase the Fisher Island Turning Basin from 1,200 to 1,500 ft (365.8 to 457.2 m), truncate the northeast section of the turning basin to minimize seagrass impacts, and deepen from −42 ft (−12.8 m) to a project depth of −50 ft; and

(4) Expand the Federal Channel and Port of Miami berthing areas in Fisherman's Channel and in the eastern end of the Lummus Island Turning Basin (LITB) by 60 ft (18.3 m) to the south for a total of a 160 ft (48.8 m) wide berthing area and will be deepened from −42 ft to a project depth of −50 ft. The Federal Channel will be widened 40 ft (12.2 m) to the south, for a 100 ft (30.5 m) total width increase in Fisherman's Channel. This component (referred to as Component 5 in the ACOE's IHA application) will deepen Fisherman's Channel and the LITB from −42 ft to a project depth of −50 ft. See Figure 1 of ACOE's IHA application for a map of the project's components.

Disposal of the estimated five million cubic yards of dredged material would occur at up to three disposal sites (seagrass mitigation area, offshore artificial reef mitigation areas, and the Miami Offshore Dredged Material Disposal Site). This project was previously evaluated under an Environmental Impact Statement (EIS) titled “Miami Harbor Miami-Dade County, Florida Navigation Study, Final General Reevaluation Report and Environmental Impact Statement,” prepared under the National Environmental Policy Act, and a Record of Decision for the project was signed on May 22, 2006. The original proposed project included six components, two of which (components four and six) have been removed. The EIS provides a detailed explanation of project location as well as all aspects of project implementation. It is also available online for public review at:
http://www.saj.usace.army.mil/Divisions/Planning/Branches/Environmental/DOCS/OnLine/Dade/MiamiHarbor/NAV_STUDY_VOL-1_MIAMI.pdf.

To achieve the deepening of the Miami Harbor from the existing depth of −45 ft (−13.7 m) to project depth of −52 ft, pretreatment of some of the rock areas may be required using confined underwater blasting, where standard construction methods are unsuccessful due to the hardness of the rock. The ACOE has used two criteria to determine which areas are most likely to need confined blasting for the Miami Harbor expansion: (1) Areas documented by core borings to contain hard and/or massive rock; and (2) areas previously blasted in the harbor during the 2005 confined blasting and dredging project.

The duration of the confined blasting is dependent upon a number of factors including hardness of rock, how close the drill holes are placed, and the type of dredging equipment that will be used to remove the pretreated rock. Without this information, an exact estimate of how many confined “blast days” will be required for the project cannot be determined. The harbor deepening project at Miami Harbor in 2005 to 2006 estimated between 200 to 250 days of confined blasting with one shot per day (a blast day) to pre-treat the rock associated with that project; however, the contractor completed the project in 38 days with 40 confined blasts. A shot, or blast, is an explosion made up of a group of blast holes set in a pattern referred to as a blast array that are detonated all at once or in a staggered manner with delays between them. A blast hole is the hole drilled into the bottom substrate that will be filled with explosives, capped with stemming, and detonated.

The upcoming expansion at Miami Harbor scheduled to begin in fall/winter of 2012 currently estimates a maximum of 600 blast days for the entire multi-year project footprint. The ACOE estimates a maximum number of 313 blast days for the duration of this IHA (
i.e.,
365 days in a year minus 52 Sundays [no confined blasting is allowed on Sundays due to local ordinances]). A blast day is defined as one confined blast event/day. A blast event is made up of all the actions during a shot, this includes the Notice of Project Team and Local Authorities, which occurs two hours before the blast is detonated, through the end of the protected species watch, which last 30 minutes after the blast detonation. A typical blast timeline consists of: Notice to Project Team and Local Authorities (T minus 2 hours), protected species watch begins (T minus 1 hour), Notice to Mariners (channel closes, T minus 15 minutes), fish scare (T minus 1 minute), blast detonation, all clear signal (T plus 5 minutes), protected species watch ends (T plus 30 minutes), and delay capsule—if an animal is observed in either the danger or safety zones, the blast is delayed to monitor the animal until it leaves, on its own volition, from both the danger and safety zones (can occur between T minus 1 hour and detonation). There may be more than one confined blast event in a calendar day. While confined blasting events will occur only during daylight hours, typically six days a week. Other operations associated with the action (
i.e.,
dredging activities) will take place 24 hours a day, typically seven days a week. Confined blasting activities normally will not take place on Sundays due to local ordinances. The contractor may drill the blast array (
i.e.,
to physically drill the holes in the substrate to be removed in the pattern designed by the blasting engineer to remove the rock in the manner he/she needs to achieve the needed results) at night and then blast after at least two hours after sunrise (1 hour, plus one hour of monitoring). After detonation of the first explosive array, a second array may be drilled and detonated before the one-hour before sunset prohibition is triggered. An explosive array is the pattern of blast holes drilled into the bottom substrate that will be fractured by the blast detonation.

At this time, the ACOE has not selected a contractor and thus does not have a contractor-developed confined blasting plan from the contractor specifically identifying the number of holes that will be drilled, the amount of explosives that will be used for each hole, the number of confined blasts per day (usually no more than two per a day) or the number of days the construction is anticipated to take to complete. The ACOE is required to have all authorizations and permits completed (including the possession of an IHA) prior to the request for proposal and advertising the contract, per the Competition in Contracting Act, and the Federal Acquisition Regulations. While the ACOE does not have contract bids at this time, it is possible to make reasonable estimates of the bounds based on previous similar projects that have been conducted by the ACOE here and at other locations. NMFS supports the use of the worst-case scenarios to estimate confined blasting activities and associated potential impacts.

Drill holes are small in diameter (typically 2 to 4 in [5.1 to 10.2 cm] in diameter) and only 5 to 10 ft (1.5 to 3.1

m) deep, drilling activities take place for a short time duration, with no more than three holes being drilled at the same time (based on the current drill-rigs available in the industry that range from one to three drills). During the 2005 confined blasting event, dolphins were seen near the drill barge during drilling events and the ACOE did not observe avoidance behavior. No measurements associated with noise from drilling small blast holes have been recorded. The ACOE does not expect incidental harassment from drilling operations and is not requesting take associated with this activity.

Although the ACOE does not have a specific contractor-provided confined blasting plan, the ACOE developed plans and specifications for the project that direct the contractor to do certain things in certain ways and are basing these plans and specifications on the previous deepening project in Miami Harbor (construction was conducted in 2005 to 2006).

The previous ACOE project in Miami Harbor required a maximum weight of explosives used in each delay of 376 pounds (lb) (170.6 kilograms [kg]) and the contractors blasted once or twice daily from June 25 to August 25, 2005, for a total of 40 individual blasts in 38 days of confined blasting. The 2005 project, which utilized confined blasting, was limited to Fisherman's Channel and the Dodge-Lummus Island Turning Basin (see Figure 2 of ACOE's IHA application, which shows the confined blasting footprint for the 2005 project), whereas the project described in the ACOE's application includes Fisherman's Channel, Dodge-Lummus Island Turning Basin, Fisher Island Turning Basin, and Inner and Outer Entrance Channel. This larger area will result in more confined blasting for this project than was completed in 2005, as it includes areas not previously blasted in 2005.

A copy of the
Federal Register
notice of issuance for the IHA from 2003 (68 FR 32016, May 29, 2003), the IHA renewal from 2005 (70 FR 21174, April 25, 2005), and the final biological monitoring report from the ACOE's Miami Harbor Phase II project (completed in 2006) is attached to the ACOE's application and available on NMFS's Web site at:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.
For the new construction at Miami Harbor, the ACOE expects the project may take multiple years, and the ACOE will seek subsequent renewals of this IHA after issuance, with sufficient time to prevent any delay to the project.

For the deepening at Miami Harbor, the ACOE has consulted with blasting industry experts and believes, based on the rock hardness and composition at Miami Harbor, a maximum charge weight per delay of 450 lbs (204.1 kg) should be expected. The minimum charge weight will be 10 lbs (4.5 kg). A delay is a period of time (in milliseconds) between small detonations that are part of the total charge weight of the entire detonation.

The focus of the confined blasting work at the Miami Harbor is to pre-treat the massive limestone formation that makes up the base of Miami Harbor prior to removal by a dredge utilizing confined blasting, meaning the explosive shots would be “confined” in the rock. Typically, each blast array is set up in a square or rectangle area divided into rows and columns (see Figures 3, 4, and 5 in the ACOE's IHA application). A typical blast array is 10 holes long by 4 holes wide with holes being spaced 40 ft (12.2 m) apart covering an area of 4,000 ft
2
(371.6 m
2
). Blast arrays near bulkheads can be long-linear feature of one-hole wide by 8 or 10 holes long (see Figure 4 of the IHA application).

In confined blasting, each charge is placed in a hole drilled in the rock approximately 5 to 10 ft (1.5 to 3.0 m) deep; depending on how much rock needs to be broken and the intended project depth. The hole is then capped with an inert material, such as crushed rock. This process is referred to as “stemming the hole” (see Figure 6 and 7 of ACOE's IHA application; each bag as shown contains approximate volume of material used per discharge). The ACOE used this technique previously at the Miami Harbor Phase II project in 2005. NMFS issued an IHA for that operation on May 22, 2003 (68 FR 32016, May 29, 2003) and renewed the IHA on April 19, 2005 (70 FR 21174, April 25, 2005).

For the Port of Miami expansion project (Miami Harbor Phase II) that used confined blasting as a pre-treatment technique, the stemming material was angular crushed rock. (Stemming is the process of filling each borehole with crushed rock after the explosive charge has been placed. After the blasting charge has been set, then the chain of explosives within the rock is detonated. A chain of explosives refers to all of the detonations within the blast array, without regard to how many holes are in the array. They will detonate within milliseconds of each other. Stemming reduces the strength of the outward pressure wave produced by blasts.) The optimum size of stemming material is material that has an average diameter of approximately 0.05 times the diameter of the blast-hole. The selected material must be angular to perform properly (Konya, 2003). For the ACOE's project, specifications will be prepared by the geotechnical branch of the Jacksonville District.

The specifications for any construction utilizing the confined blasting for the deepening of Miami Harbor will have similar stemming requirements as those that were used for the Miami Harbor Phase II project in 2005 to 2006. The length of stemming material would vary based on the length of the hole drilled, however a minimum of two 2-ft (0.6 m) walls will be included in the project specific specifications. Studies have shown that stemmed blasts have up to a 60 to 90 percent decrease in the strength of the pressure wave released, compared to open water blasts of the same charge weight (Nedwell and Thandavamoorthy, 1992; Hempen
et al.,
2005; Hempen
et al.,
2007). However, unlike open water (unconfined) blasts (see Figure 8 of ACOE's IHA application), very little peer-reviewed research exists on the effects that confined blasting can have on marine animals near the blast (Keevin
et al.,
1999). The visual evidence from a typical confined blast is shown in Figure 9 of ACOE's IHA application.

In confined blasting, the detonation is conveyed from the drill barge to the primer and the charge itself by Primacord and Detaline. These are used to safely fire the blast from a distance to ensure human safety from the blast. The Primacord and Detaline used on this project have a specific grain weight, and they burn like a fuse. They are not electronic. The time delay from activation to detonation of the charge is less than one second.

To estimate the maximum poundage of explosives that may be utilized for this project, the ACOE has reviewed previous confined blasting projects, including San Juan Harbor, Puerto Rico in 2000, and Miami Harbor, Florida in 2005. Additional data was also reviewed from the New York Harbor deepening project (ACOE, 2004 and Keevin
et al.,
2005) and the Wilmington Harbor project (Settle
et al.,
2002). The San Juan Harbor and 2005 Miami Harbor projects are most similar to the existing project in general environment, hardness/massiveness of rock, and species composition. The San Juan Harbor project's heaviest confined blast event using explosives was 375 lbs (170.1 kg) per delay and in Miami it was 376 lbs (170.6 kg) per delay. Based on discussion with the ACOE's geotechnical engineers, it is expected

that the maximum weight of delays for Miami Harbor will be larger since the rock is deeper, and expected to be harder and massive, in comparison to the previous two blasting projects.

Based upon industry standards and ACOE Safety & Health Regulations, the confined blasting program will follow these operating guidelines:

• The weight of explosives to be used in each confined blast will be limited to the lowest poundage of explosives that can adequately break the rock.

• Drill patterns (
i.e.,
holes in the array) are restricted to a minimum of 8 ft (2.4 m) separation from a loaded hole.

• Hours of confined blasting are restricted from two hours after sunrise to one hour before sunset to allow for adequate observation of the project area for marine mammals.

• Selection of explosive products and their practical application method must address vibration and air blast (overpressure) control for protection of existing structures and marine wildlife.

• Loaded blast holes will be individually delayed to reduce the maximum lbs per delay at point detonation, which in turn will reduce the mortality radius.

• The blast design will consider matching the energy in the “work effort” of the borehole to the rock mass or target for minimizing excess energy vented into the water column or hydraulic shock.

• Delay timing adjustments with a minimum of 8 milliseconds (ms) between delay detonations to stagger the blast pressures and prevent cumulative addition of pressures in the water.

Test Blast Program

Prior to implementing a construction blasting program, a test blast program will be completed. The test blast program will have all the same protective monitoring and mitigation measures in place for protected species as blasting operations for construction purposes. The purpose of the test blast program is to demonstrate and/or confirm the following:

• Drill boat capabilities and production rates;

• Ideal drill pattern for typical boreholes;

• Acceptable rock breakage for excavation;

• Tolerable vibration level emitted;

• Directional vibration; and

• Calibration of the environment.

The test blast program begins with a single range of individually delayed holes and progresses up to the maximum production blast intended for use. The test blast program will take place in the project area and will count toward the pre-treatment of material, since the blasts of the test blast program will be cracking rock. Each test blast is designed to establish limits of vibration and air blast overpressure, with acceptable rock breakage for excavation. The final test event simulates the maximum explosive detonation as to size, overlying water depth, charge configuration, charge separation, initiation methods, and loading conditions anticipated for the typical production blast.

The results of the test blast program will be formatted in a regression analysis with other pertinent information and conclusions reached. This will be the basis for developing a completely engineered procedure for the construction blasting plan.

During the test blast program, the following data will be used to develop a regression analysis:

• Distance;

• Pounds per delay;

• Peak particles velocities (Threshold Limit Value [TVL]);

• Frequencies (TVL);

• Peak vector sum; and

• Air blast, overpressure.

As part of the development of the protected species monitoring and mitigation protocols, which will be incorporated into the plans and specification for the project, ACOE will continue to coordinate with the resource agencies and non-governmental organizations (NGOs) to address concerns and potential impacts associated with the use of blasting as a construction technique.

Additional details regarding the confined blasting and dredging project can be found in the ACOE's IHA application and EIS. The EIS can also be found online at:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.

Description of the Dates, Duration, and Specified Geographic Region

At this time the ACOE has not yet awarded a contract or given a Notice to Proceed (NTP) with a specific date for the initiation of construction activities within the Port of Miami. However, the ACOE requested that the first IHA be issued by the end of July, 2012, with an effective date of March 15, 2013, to allow for the advertisement of the contract for construction in September, 2012; award the contract and provide the NTP to the selected in February, 2012 to the selected contractor, resulting in construction work beginning in March 15, 2013. After receiving NTP, the contractor will have 45 days to begin dredging activities, but blasting activities shall not begin until after March 15, 2013. The construction activities are expected to take up to 26 months and at this time, it is possible that confined blasting could take place at any time during construction. The ACOE also notes that multiple IHAs (up to three) will be needed and requested for this project due to the project duration.

The confined blasting activities will be limited to waters shallower than 60 ft. (18.3 m) and located entirely on the continental shelf and will not take place seaward of the outer reef. The specified geographic area of the construction will be within the boundaries of the Port of Miami, in Miami, Florida (see Figure 11 of the ACOE's IHA application). The Port of Miami is an island facility consisting of 518 upland acres and is located in the northern portion of Biscayne Bay in South Florida. The City of Miami is located on the west side of the Biscayne Bay; the City of Miami Beach is located on an island on the northeast side of Biscayne Bay, opposite of Miami. Both cities are located in Miami-Dade County, Florida, and are connected by several causeways crossing the bay. The Port of Miami is the southernmost major port on the Atlantic Coast. The Port of Miami's landside facilities are located on Dodge-Lummus Island, which has a GPS location 25°46′05″ North 80°09′40″ West. See Figure 11 of the ACOE's IHA application for more information on the location of the project area in the Port of Miami.

Comments and Responses

A notice of preliminary determinations and proposed IHA for the ACOE confined blasting operations was published in the
Federal Register
on November 18, 2011 (76 FR 71517). During the 30 day public comment period, NMFS received combined comments from the Sierra Club Miami Group, Biscayne Bay Waterkeeper, and Kent Harrison Robbins (Robbins
et al.
), as well as comments from the Marine Mammal Commission (Commission). The comments are posted online at:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm.
Following are their substantive comments and NMFS' responses:

Comment 1:
Robbins
et al.
states that the ACOE's request for an IHA does not comply with the regulatory and legal standards for issuance of an IHA because the project proposes 600 days of confined blasting with an average of one or two blasting periods per day. To authorize an IHA for a project longer than a one-year period undermines the purpose of the authorization because the cumulative and continued effects of the

confined blasts on the resident and transient bottlenose dolphin populations known to both the Biscayne Bay and Atlantic Shelf areas cannot be properly assessed by the limited scope of an IHA analysis, which can consider impact not to exceed one year.

Response:
The commenter incorrectly states the project will have 600 days of blasting. The ACOE estimates a maximum number of 313 blast days for the duration of this IHA (
i.e.,
365 days in a year minus 52 Sundays [normally no confined blasting is allowed on Sundays due to local ordinances]), with no more than one confined blast event at a time and no more than two confined blast events per a single day. A calendar day is 24 hours. A blast day/blast event (
i.e.,
approximately 1 hour 30 minutes in length) is the series of events beginning one hour before the detonation through 30 minutes after the detonation. There may be more than one blast day/blast event per calendar day, they will not occur simultaneously.

50 CFR 216.107 states that IHAs will be valid for a period of time not to exceed one year but may be renewed for additional periods of time not to exceed one year for each reauthorization; therefore, the promulgation of regulations and the subsequent issuance of Letters of Authorization (LOAs) to the ACOE for the confined blasting operations in the Port of Miami is not necessary or required.

NMFS considered cumulative effects of the confined blasting on the resident and transient bottlenose dolphin populations (
i.e.,
Biscayne Bay and Western North Atlantic Central Florida Coastal stocks) in the action area as part of its NEPA analysis and prepared an “Environmental Assessment for Issuance of an Incidental Harassment Authorization for U.S. Army Corps of Engineers Confined Blasting Operations During the Port of Miami Construction Project in Miami, Florida,” which analyzes the project's purpose and need, alternatives, affected environment, and environmental effects for the action prior to making a determination on the issuance of the IHA. NMFS also considered these cumulative effects before making its negligible impact determination for issuance of the IHA to the ACOE. NMFS' EA and ACOE's FEIS adequately address the cumulative effects of relatively short-term confined blasting operations in relation to long-term noise and events from other past, present and reasonably foreseeable future anthropogenic sources, such as dredging, construction and demolition activities, shipping, commercial fishing, recreational fishing and boating, military readiness activities, and other human activities in the action area. These other activities are considered to be long-term and continuous.

Comment 2:
Robbins
et al.
states that relative to the 2005/2006 Port of Miami safety zone calculations, the current application does not reflect the significant blasting area and duration of the project as well as the high maximum weight which will be employed in this project. In addition, the ACOE has not addressed how it will ensure that stemming the blast hole will be more effective in this round of blasting, especially when considering the specific nature of the blast area which is in a channel, which may carry sound and pressure farther and/or in a more concentrated route. Robbins
et al.
states that there should be improved methods for stemming blast holes. Studies such as Jordan (2007) and Hempen & Keevin (2007) have shown that the practice of confined blasting such as those done at the Port of Miami in 2005 significantly reduces the pressure wave released as compared to open water discharges of the same weight. However, if the protocol of stemming the holes to benefit the marine community is not properly executed, these mitigation methods are not creating the positive changes that are so critical to reducing the take number of fish, sea turtles, and manatees. The blast area is also in an extremely sensitive part of Biscayne Bay, sharing a boundary with a critical wildlife area frequented by bottlenose dolphin.

Response:
The ACOE's IHA application clearly defines the Miami Harbor Deepening Project's action area and expected project duration. Protective zone (danger, exclusion, safety, and watch) calculations will be relatively applied in comparison to 2005/2006 Port of Miami safety zone calculations. The term “relative” means that the calculations utilized to determine the danger, exclusion, safety, and watch zones that are being used are based upon the actual charge weights that will be utilized for this effort—which may be as high as 450 lbs per delay (as compared to 376 lbs per delay in the 2005/2006 confined blasting in the Port of Miami), which consequently will result in larger protective zones. For instance, the calculated area of the danger zone for the largest blast conducted in 2005/2006 was 11,059,023.62 ft
2
(1,027,416.91 m
2
), representing 0.09% of the total area of Biscayne Bay, and the calculated area of the danger zone for the largest confined blast proposed for this effort is 12,466,026.04 ft
2
(1,158,131.72 m
2
), representing 0.10% of the total area of Biscayne Bay. This is a difference of 1,407,002.42 ft
2
(130,714.802 m
2
), or an increase in the total impact area of 0.01% of the total area of Biscayne Bay, or 12% increase in impact area specific to the confined blast.

Regarding the effectiveness of the stemming, Section 3.5.5 of the ACOE's project confined blasting specification (02 10 00) state:

3.5.5 Stemming

All blast holes shall be stemmed. The Blaster or Blasting Specialist shall determine the thickness of stemming using blasting industry conventional stemming calculation. The minimum stemming shall be 2 ft (0.61 m) thick. Stemming shall be placed in the blast hole in a zone encompassed by competent rock. Measures shall be taken to prevent bridging of explosive materials and stemming within the hole. Stemming shall be clean, angular to subangular, hard stone chips without fines having an approximate diameter of
3/8
to
1/2
in (0.95 to 1.27 cm). A barrier shall be placed between the stemming and explosive product, if necessary, to prevent the stemming from settling into the explosive product. Anything contradicting the effectiveness of stemming shall not extend through the stemming.

The specifications clearly direct the contractor to utilize and employ blasting industry standards and specifically requires the contractor to place the blast hole in a zone encompassed by competent rock to minimize the potential rifling (when a hole is not well confined). The ACOE's Master Blaster reviews all proposed contractor blasting plans to ensure compliance with the project specifications.

NMFS uses the best scientific evidence available in its environmental analysis and the development of monitoring and mitigation measures required in the IHA issued to the ACOE. In the IHA, NMFS requires the ACOE to implement mitigation measures (
e.g.,
limiting the weight of explosives; capping explosives in loaded holes; minimum separation distance of loaded holes; staggering detonations; restricting hours when blasting can occur; calculating, establishing, and monitoring danger, exclusion, safety, and watch zones, etc.) during confined blasting operations that are expected to reduce the potential for incidental take and ensure the activity will have the least practicable impact on marine mammals and their habitat.

The ACOE has previously noted in the project environmental coordination documents (project FEIS and Biological Assessments) and continues to recognize that the project area is adjacent to the Bill Sadowski Critical Wildlife Area. NMFS' IHA requires the ACOE to implement monitoring and mitigation measures so that the confined

blasting operations will have the least practicable impact on bottlenose dolphins in the action area.

Comment 3:
Robbins
et al.
states that as there is no evidence presented that drilling and dredging activities themselves do not increase harassment, these activities should be further tested. The only construction activity restricted to daylight hours is the blasting and all other work is permissible through the night when there will be no watch plan in place or possible, so it is unclear the amount of harm that these activities will cause. The extended nature of this project will also adversely impact the habitat of the bottlenose dolphin, sea turtles, and other marine mammals because the project is dredging approximately 415 acres of bay bottom, coral reef, and sea grass beds (and not including damage to outer shelf reef systems from barge anchoring chains) and FDEP is only requiring a total of 14 acres of seagrass mitigation and 9.78 of artificial reef mitigation.

Response:
The ACOE has agreed to collect sound recordings of drilling operations during the confined blasting operations at Miami Harbor to help the ACOE and NMFS better characterize the noise associated with drilling activities at confined blasting projects throughout the U.S. The ACOE has conducted interviews with Protected Species Observers (PSOs) having more than 25 years of experience monitoring blasting activities. These individuals have stated that no avoidance behavior from any marine mammal species in many parts of the country, including bottlenose dolphins, has been observed in association with drilling activities associated with confined underwater blasting.

The ACOE conducts dredging operations 24 hours a day throughout the U.S. and, to date, utilizes the same types of dredging equipment planned to be used for the blasting and dredging operations as part of the Miami Harbor Deeping Project. The ACOE's Jacksonville District Local Master Guide Specification (Section 01 57 20) covers the requirements for environmental protection during construction activities, which includes monitoring and mitigation measures for dredging operations. This document can be found online at:
www.saj.usace.army.mil/Divisions/Engineering/DOCS/CADD/docsect/01_57_20.pdf.
Neither the ACOE, nor NMFS, has determined that dredging operations, in previously dredged and maintained navigation channels, has the potential to result in the incidental take of cetaceans.

Habitat loss associated with the project is limited primarily to an existing and maintained Federal channel that is 0.07% of the total area of Biscayne Bay, which is habitat area for the Biscayne Bay stock of bottlenose dolphins, and 0.0009% of the 20 m (65.6) isobar off the coast of Florida, which is habitat area for the Western North Atlantic Central Florida Coastal stock of bottlenose dolphin. The ACOE also conducted consultations with NMFS Southeast Regional Office (SERO) under the ESA and Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA) regarding designated critical habitat of ESA-listed species and essential fish habitat (EFH).

The IHA issued to ACOE provides monitoring and mitigation requirements that will protect marine mammals from injury, serious injury, or mortality. The ACOE is required to comply with the IHA's requirements. Under the MMPA, IHAs must include means of effecting the least practicable impact on marine mammal species and their habitat (
i.e.,
impacts to seagrass, hardbottom or coral habitats). Monitoring and mitigation measures are designed to comply with this requirement.

Comment 4:
Robbins
et al.
states that the ACOE is seeking, and NMFS has noticed, a legally-defective IHA by authorizing harassment of marine mammal species arising from activities expected to last for more than one year. NMFS cannot issue an IHA for the proposed blasting operations, as they are part of the overall Port of Miami blasting and dredging project, and the substantial number of takes that will occur over the period of many years involved in the project can only be authorized through LOA regulations under section 101(a)(5)(A)(i), 16 U.S.C. 1371(a)(5)(A)(i). For this reason, NMFS must deny the IHA application, and a comprehensive analysis and due process required under rulemaking, consistent with a request for a Letter of Authorization, should be required.

Response:
NMFS disagrees with the commenter's statement. The ACOE requested an IHA in its adequate and complete application, and does not need to pursue the promulgation of regulations and subsequent LOAs by NMFS under section 101(a)(5)(A) of the MMPA for this specified activity. 50 CFR 216.107 states that except for activities that have the potential to result in serious injury or mortality, which must be authorized under § 216.105, IHAs may be issued, following a 30-day public review period, to allow activities that may result in only the incidental harassment of a small number of marine mammals. IHAs are valid for a period of time not to exceed one year but may be renewed for additional periods of time not to exceed one year for each reauthorization; therefore, the promulgation of regulations and the subsequent issuance of LOAs to the ACOE for the confined blasting operations in the Port of Miami is not necessary or required.

Comment 5:
The proposed safety zone surrounding the blasting operations is [in]sufficient and detrimental to several marine mammals covered by the IHA.

Response:
The safety zone is calculated to be twice the area of the danger zone, and pressure measurements collected during in situ pressure monitoring, have shown that blast pressures return to background at the outer edge of the danger zone. Additionally, both the safety and danger zones are based on unconfined, open water blasts (which is not the case here) and the safety zones were developed by the U.S. Navy to protect naval divers working with military ordinance during warfare to ensure that divers are not injured or killed. Also, the exclusion zone is larger than the area where the ACOE has determined that Level B harassment will occur, so if the monitoring and mitigation measures implemented are successful as expected, and no detonation occurs when an animal is inside the exclusion zone, no take by Level B harassment is likely to occur.

The ACOE's specified activity only authorizes the use of confined blasting, which results in a 60 to 90 percent reduction in the strength of the pressure wave released (Hempen
et al.,
2007; Hempen
et al.,
2005; Nedwell and Thandavamoorthy, 1992) when compared to an unconfined, open water blast like those seen in other military readiness activities using explosive ordinance. It is therefore unclear how these mitigation measures and protective zones are detrimental to bottlenose dolphins in the action area. The bottlenose dolphin is the only species of marine mammal managed under NMFS jurisdiction that is expected to occur in the action area. The commenter refers to “marine mammal species” to be included in the IHA, however, only the Biscayne Bay and Western North Atlantic Central Florida Coastal stocks of bottlenose dolphins are covered by the IHA. The West Indian (Florida) manatee, which may also be found in the action area, is managed under the jurisdiction of the U.S. Fish and Wildlife Service (USFWS).

Comment 6:
Robbins
et al.
states that the Biscayne Bay stock of bottlenose dolphins is apparently isolated within the Biscayne Bay community and from any other dolphin populations, thus,

Biscayne Bay is a distinct habitat for these bottlenose dolphins that are at risk.

Response:
The available data do not support the commenter's belief that the Biscayne Bay stock of bottlenose dolphins is apparently isolated within Biscayne Bay and from any other dolphin populations. NMFS stock assessment report (2009) states that the range of the Biscayne Bay stock of bottlenose dolphins (
i.e.,
Haulover Inlet [north] and Card Sound bridge [south] boundaries) corresponds to the extent of confirmed home ranges of bottlenose dolphins observed residing in Biscayne Bay by a long-term photographic identification (photo-ID) study conducted by the NMFS SEFSC (Litz, 2007; SEFSC unpublished data), however, there have been few surveys outside of this range. These boundaries are subject to change upon further study of bottlenose dolphin home ranges within the Biscayne Bay estuarine system and comparison to an extant photo-ID catalog from Florida Bay to the south.

NMFS has to consider other information, not just the stock assessment reports, to provide a complete picture of marine mammals in the action area. There are at least five openings from the Atlantic Ocean into Biscayne Bay where bottlenose dolphins from the Biscayne Bay stock can exit the Biscayne Bay system. From the north they are: Haulover Inlet, Government Cut, Norris Cut, Bear Cut, and the Safety Valve. Additionally the Atlantic Intracoastal Waterway allows animals from Biscayne Bay to transit north into the Indian River Lagoon Estuarine System (IRLES) and South into Florida Bay. Contillo
et al.
(2011) documented that dolphins from Biscayne Bay have been observed in Florida Bay and dolphins from Florida Bay have been observed in Biscayne Bay on at least 20 occasions since 1999. Additionally, Biscayne Bay dolphins have been documented exiting the bay and been seen outside of Biscayne Bay in nearshore coastal waters off of Miami-Dade County, and animals documented as belonging to the coastal stock have been documented in Biscayne Bay on numerous occasions (Contillo, pers. comm., 2011). In the NMFS stock assessment report (2009), NMFS states that at least one dolphin was “confirmed to be of the offshore morphotype by genetic testing and therefore not a Biscayne Bay resident.” These data document that the Biscayne Bay stock of bottlenose dolphins (while likely are residents) are not isolated within Biscayne Bay, can and do exit Biscayne Bay, and that bottlenose dolphins from outside the stock enter Biscayne Bay and can mix with the Biscayne Bay stock.

Comment 7:
Robbins
et al.
states that the northern portion of Biscayne Bay, which is geographically distinct from the southern portion of Biscayne Bay, is no longer polluted contrary to the allegations in the ACOE's IHA application and NMFS' notice of preliminary determinations and a proposed IHA. The corridor for the proposed 600 days of twice-a-day explosive blasting is located along the east-west Government Cut and Miami Harbor Channel bay corridor, which is the geographical divide between the northern and southern portions of Biscayne Bay. While there may have been a time decades ago when there were serious problems of industrial and municipal pollution of the northern portion of Biscayne Bay, that is not the current conditions of northern Biscayne Bay. Much of the municipal pollution and industrial effluent into Biscayne Bay and its tributaries has been eliminated over the prior decades due to strict code enforcement and the construction of deep well storage filtration systems as part of comprehensive plans adopted by the localities. It is a healthy estuarine habitat for dolphins and other sea mammals in the northern bay. Not noted in the ACOE IHA application and NMFS' notice of preliminary determinations and a proposed IHA is the enhancement of the northern Biscayne Bay estuary by the replanting of mangroves and the creation of Oleta River Florida Park. Thus, the suggestion that the northern portion of Biscayne Bay is unhealthy due to municipal and industrial pollution is not true. The northern portion of Biscayne Bay constitutes a significant wildlife habitat that supports marine mammals and other wildlife.

Response:
The commenter is referring to the citation by NMFS in its stock assessment report (2009) for the Biscayne Bay stock of bottlenose dolphins that states “the northern portion of Biscayne Bay is surrounded by the cities of Miami and Miami Beach and is therefore heavily influenced by industrial and municipal pollution sources (Bialczak
et al.,
2001).” Litz (2007) found that tissue samples collected for genetic and persistent organic pollutants (POP) analysis from dolphins in Biscayne Bay, male dolphins with home ranges in the northern portion of Biscayne Bay had polychlorinated biphenyl (PCB) levels five times higher than their counterparts with southern home ranges. This trend continued for dichlorodiphyltrichloroethane (DDT) (twice as high); chlordanes (four times higher); polybrominated diphenyl ethers (PBDE) (three times higher), and other pesticides (three times higher). The same trend was also observed in female dolphins when northern vs. southern animals' POP levels were compared. While it can be agreed that water quality in Biscayne Bay is better than it has been previously, high levels of POP, commonly associated with land-based pollution sources, remain higher in north Biscayne Bay then in the remainder of the Biscayne Bay system and continue to impact marine species inhabiting that part of Biscayne Bay.

Additionally, the commenter incorrectly states the project will have 600 days of blasting. The ACOE estimates a maximum number of 313 blast days for the duration of this IHA (
i.e.,
365 days in a year minus 52 Sundays [normally no confined blasting is allowed on Sundays due to local ordinances]), with no more than one confined blast event at a time and no more than two confined blast events per a single day. A calendar day is 24 hours. A blast day/blast event (
i.e.,
approximately 1 hour 30 minutes in length) is the series of events beginning one hour before the detonation through 30 minutes after the detonation. There may be more than one blast day/blast event per calendar day, they will not occur simultaneously.

Comment 8:
Robbins
et al.
states that the proposed level of take analysis is faulty. While Level A harassment causing tympanic membrane (TM) rupture with correlated permanent hearing impairment is intended to be avoided, NMFS admits that it is “unknown at this time” as the farthest distance at which a dolphin would be exposed to an energy flux density (EFD) from an explosive which would cause Level A harassment (76 FR 71525). What this means is that the explosive detonations proposed may result in permanent hearing impairment and Level A harassment. Nonetheless, without this knowledge, the ACOE proposes allowing detonations. Without rational basis, the NMFS notice addresses Level B harassment without discussing why the dolphins should be permitted to be exposed to possible Level A harassment including permanent hearing loss.

NMFS also acknowledges that the Level B harassment definition also includes noise exposures below TTS that may result in behavioral modifications to resident animals. Without any scientific basis, the NMFS notice concludes that the behavioral modification criteria would not apply

“because there will be only two blasting events a day” and each blast event will be multiple (440 in a matrix) within a few microseconds.

The ACOE's IHA application and NMFS'
Federal Register
notice do not correctly consider the impact of the blasting twice a day for 600 days on the behavior of the dolphins. Indeed, under the criteria for Level B harassment, “behavioral disruption” must be considered when TTS occurs. Under the harassment criteria for NMFS, Level B harassment includes behavioral disruption associated with TTS. As a result of a misconstruction of the dual criteria for harassment, the ACOE and NMFS do not consider the behavioral impact of the explosives and the proposed 600 days of twice-a-day blasting. Instead, it conclusively determines that twice a day blasting is not “multiple detonations” and, therefore, does not consider the third criteria of Level B harassment, sub-TTS impact with behavioral disruption, and utterly ignores the dual criteria of Level B harassment with TTS, which requires consideration of associated behavioral modification.

Response:
The commenter incorrectly states the project will have 600 days of blasting. The ACOE estimates a maximum number of 313 blast days for the duration of this IHA (
i.e.,
365 days in a year minus 52 Sundays [normally no confined blasting is allowed on Sundays due to local ordinances]), with no more than one confined blast event at a time and no more than two confined blast events per a single day. A calendar day is 24 hours. A blast day/blast event (
i.e.,
approximately 1 hour 30 minutes in length) is the series of events beginning one hour before the detonation through 30 minutes after the detonation. There may be more than one blast day/blast event per calendar day, but they will not occur simultaneously.

NMFS disagrees with the commenter that the proposed level of take analysis is faulty in the ACOE's IHA application and NMFS's notice of preliminary determinations and proposed IHA (76 FR 71517, November 18, 2011). The IHA issued to the ACOE for the confined blasting operations in the Port of Miami only authorizes the incidental take of bottlenose dolphins by Level B harassment; no incidental takes by Level A harassment (injury), serious injury, or mortality are anticipated or authorized.

Because for ACOE's confined blasting activities all of the holes in the delay will explode within a few seconds at most (the blast array will be timed with a minimum eight milliseconds delay between detonations to stagger the blast pressures and prevent cumulative addition of pressures in the water), and a maximum of only two confined blasting events will occur in a day separated by a minimum of four to six hours (worst case scenario). NMFS applies the explosive TTS threshold which then allows us to estimate the number of animals that may incur TTS and account for any associated behavioral disruption.

The multiple detonations threshold was designed for specified activities like gunnery exercises where tens, to hundreds, to thousands of individual explosions continue over minutes to hours that would clearly have the potential to cause behavioral harassment associated at levels lower than those that result in TTS. The Level B harassment (behavioral) threshold criteria of 177 dB re 1 μPa
2
s would not apply to the ACOE's activity because there will only be a maximum of two blasting events a day (minimum four to six hours apart), and the multiple (staggered) detonations are within a few milliseconds of each other and do not last more than a few seconds in total duration per a blasting event.

Also, the exclusion zone is larger than the area where the ACOE has determined that Level B harassment will occur, so if the monitoring and mitigation measures are successful as expected, and no duration occurs when an animal is inside the exclusion zone, no take by Level B harassment is likely to occur.

The primary potential impact to the Atlantic bottlenose dolphins occurring in the Port of Miami action area from the detonations is Level B harassment (in the form of TTS and any associated behavioral disruption resulting) incidental to noise generated by confined explosives. In addition, NMFS believes that the monitoring and mitigation measures required by the IHA will further limit incidental take to Level B harassment and have the least practicable impact on marine mammal species or stocks in the action area.

Comment 9:
Robbins
et al.
states that the blasting and resulting behavioral modification may sever the distinct Biscayne Bay bottlenose dolphin stock between the northern and southern parts of Biscayne Bay. The issue of behavioral modification is significant and, without any scientific analysis, is not considered by the ACOE's IHA application or NMFS'
Federal Register
notice. Biscayne Bay is a single identified habitat for a distinct genetic stock of bottlenose dolphins. It is transected by a corridor of about four miles (mi) (6.4 kilometers [km]). Half that corridor constitutes the blasting area. That corridor physically divides the northern and southern half of Biscayne Bay. The northern portion of Biscayne Bay, which is substantially a shallow grass covered environment where 69 of the 229 resident bottlenose dolphins have been found to reside, is unlike the southern portion of Biscayne Bay, which is a wide gulf of substantial width and breadth. Access to the narrow northern portion of Biscayne Bay is limited to passages below two bridges, one immediately adjacent to the blasting corridor. The only other means of egress from the northern portion of Biscayne Bay is below a bridge, at Bakers Haulover, cut approximately 9 mi (14.5 km) north, which provides access to the coastal waters adjacent to beaches without surrounding mangrove or other estuarine conditions in which the distinct Biscayne Bay dolphin community has been found to reside. The Biscayne Bay stock, which is genetically distinct from the coastal stock of dolphins, does not breed with the dolphins along the coast. Essentially, the blasting may create a significant acoustical barrier between the northern and southern portions of Biscayne Bay.

It has not been studied or determined whether the current bottlenose dolphins that reside in the northern portion of Biscayne Bay would be stressed by their isolation from the remainder of their resident community or would alternatively abandon their habitat in the northern portion of Biscayne Bay where 30% of the identified individuals currently reside. There is not consideration of data or presentation of scientific analysis that established the 600 days of blasting would not disrupt the behavioral patterns of the community of dolphins which reside in both the northern and southern areas of Biscayne Bay. Given the known intelligence of the dolphins, and their sensitive hearing, it is necessary for the applicant to establish with data and analysis that the blasting would not disrupt the natural behavioral patterns of the community of bottlenose dolphins in Biscayne Bay. No such analysis was presented in the ACOE's IHA application or in the NMFS
Federal Register
notice. How the blasting would disturb the Biscayne Bay stock by causing the disruption of their traversing across the blasting area as well as their breeding and feeding and related activities needs to be studied thoroughly before any incidental take from blasting is considered.

The ACOE and NMFS admit that they are “unable to determine how the temporary modification of the action area by the proposed construction and blasting will impact the two stocks of

dolphins expected to be present in the Port of Miami” (76 FR 71526, November 18, 2011). That statement suggests that the NMFS
Federal Register
notice does not recognize a significant distinction of the geographical location of the blasting that will impact the two different stocks (estuarine bay vs. coastal) in different ways. The impact to the coastal stock may very well be occasional because the blast area merely juts into the ocean coastal area, but the impact on the estuarine bay stock will be ongoing and will not be temporary. The disruption of the Biscayne Bay stock will be during the entire term of the 600 days of blasting and, if long term behavioral modification has occurred, for perhaps years thereafter. The NMFS' use of the word “temporary” is disingenuous given the 600 days of blasting and many more days of construction. The NMFS
Federal Register
notice acknowledges that the proposed construction and blasting” may delay or detour their movements (76 FR 71526), but does not consider that as to traversing from north to south or vice-versa, an acoustical barrier will be created and dolphins, especially cows with nursing and young calves, may avoid the dangers of the area rather than place their young at risk. The effectual trapping of the dolphins in the northern portion of Biscayne Bay will not cause their slaughter, but may change their natural behavior.

Response:
The commenter incorrectly states the project will have 600 days of blasting. The ACOE estimates a maximum number of 313 blast days for the duration of this IHA (
i.e.,
365 days in a year minus 52 Sundays [normally no confined blasting is allowed on Sundays due to local ordinances]), with no more than one confined blast event at a time and no more than two confined blast events per a single day. A calendar day is 24 hours. A blast day/blast event (
i.e.,
approximately 1 hour 30 minutes in length) is the series of events beginning one hour before the detonation through 30 minutes after the detonation. There may be more than one blast day/blast event per calendar day, they will not occur simultaneously.

NMFS believes that the confined blasting is unlikely to result in behavioral modifications that may sever the Biscayne Bay stock of bottlenose dolphins between the northern and southern parts of Biscayne Bay. A review of data collected by NMFS SEFSC before, during, and after the 2005 confined blasting event shows no difference in home range usage of bottlenose dolphins from the Biscayne Bay stock. The ACOE and NMFS expect this same response for the future confined blasting associated with the Miami Harbor Deepening Project. The project area is a commercial port environment, and the bottlenose dolphins residing in or transiting through the vicinity of the Port of Miami are likely habituated to the presence of, and noise from, numerous vessel movements ranging from large commercial vessels to small recreational craft, as well as sea planes and helicopters operating from the vicinity of Rickenbacker Causeway and overflying the Bill Sadowski Critical Wildlife Area. This ongoing commercial and recreational use of the Port of Miami's channels far exceeds the potential impact of the confined blast events associated with the deepening project that have a duration of less than 60 seconds each (from the first fish scare to the end of the actual confined blast), and with no more than two confined blast events (separated by at least four hours) occurring in one calendar day. Blasting events take from the time beginning one hour before the detonation through 30 minutes after the detonation, including any delays due to protected species. This means that the maximum duration of noise and pressure associated with confined blasts will be 120 seconds in a calendar day, which is 0.14% of all of the time in a calendar day, assuming a worst case of two confined blast events in a calendar day that last up to 60 seconds each in duration, with confined blasts occurring no more than six days a week. The ACOE took the most conservative calculation for each blast to protect natural resources. Furthermore, bottlenose dolphins residing in Biscayne Bay can transit through the Port of Miami area from north to south in two locations inside Biscayne Bay—at the Intracoastal Waterway, on the west side of the Port of Miami, which is completely outside the project area (including the safety zone) and where Fisherman's Channel meets the main channel in Government Cut, Fisher Island Turning Basin. These two corridors allow animals wishing to avoid the project area a mechanism to transit north and south. The issue of the isolation of the Biscayne Bay stock of bottlenose dolphins has already been addressed in the response to Comment 6 and is hereby incorporated by reference.

Comment 10:
Robbins
et al.
states that the history of the ACOE's blasting operations at the Port of Miami indicates substantial impacts on dolphins. The lack of data and analysis is disturbing because during the prior blasting in 2005 at the Port of Miami, which lasted only 40 days, bottlenose dolphin in the exclusion zone were sighted 12 times involving a total of 30 individuals in the exclusion zone when those prior blasts were scheduled (76 FR 71532). In other words, in 30 percent of the dates in which blasting was scheduled, dolphins were sighted in the exclusion zone. Thus, given the radius, an even greater number would have been immediately adjacent and subject to sub-TTS impacts. Once the number of blasting events increases from 40 to 1,200, it is likely that a much greater number of dolphins will be adversely affected. The 30 multiple (from 40 to 1,200) of increased blasting events may likely result in 360 incidents of dolphin groups in the exclusion zone and many times that amount within the immediate area affected by sub-TTS noise. Using the same number of individuals per group as in 2005, results in a total of 900 individual dolphins traversing the exclusion zone during the 1,200 blasting events. Of course, these high numbers assume that the dolphins will not be avoiding the area after the repetitive blasting which is an assumption that the undersigned do not accept because behavioral modification may result in dolphins avoiding the area during the course of the blasting operations.

Response:
The commenter incorrectly states the project will have 600 days of blasting. The ACOE estimates a maximum number of 313 blast days for the duration of this IHA (
i.e.,
365 days in a year minus 52 Sundays [normally no confined blasting is allowed on Sundays due to local ordinances]), with no more than one confined blast event at a time and no more than two confined blast events per a single day. A calendar day is 24 hours. A blast day/blast event (
i.e.,
approximately 1 hour 30 minutes in length) is the series of events beginning one hour before the detonation through 30 minutes after the detonation. There may be more than one blast day/blast event per calendar day, they will not occur simultaneously.

NMFS and the ACOE disagree with the comment that the history of the ACOE's confined blasting operations at the Port of Miami indicates substantial impacts on bottlenose dolphins in the action area. Utilizing the correct number of confined blast days/events and the specification requirement that when bottlenose dolphins are observed in either the danger or exclusion zone (as demonstrated in Figure 10 of the ACOE's IHA application), confined blasting operations are delayed until the animals leave the area of their own volition. The assumptions in the commenter's analysis indicating that bottlenose dolphins observed in the

exclusion zone (which includes the danger zone within its boundaries) are adversely affected by the planned confined blasting is flawed. The detonations are delayed until the dolphins leave the exclusion zone, where pressure monitoring has demonstrated that pressures at the edge of the danger zone return to background levels (Hempen
et al.,
2007). By ensuring the animals have left the exclusion zone (an area larger than the danger zone) before the confined blast is detonated, the ACOE and NMFS believe that the project will have minimal impact on the stocks of bottlenose dolphins, since the animals outside the danger zone will not be subjected to pressures higher than the surrounding background environment. Also, the exclusion zone is larger than the area where the ACOE has determined that Level B harassment will occur, so if the monitoring and mitigation measures implemented are successful as expected, and no detonation occurs when an animal is inside the exclusion zone, no take by Level B harassment is likely to occur.

In contrast to the commenter's statement, the ACOE's 2005/2006 confined blasting and dredging project did not have any documented incidents of take by Level B harassment during the 40 confined blast days/events. One bottlenose dolphin was recorded as jumping after a confined blast detonation out of the 58 bottlenose dolphins observed in the project area during the blasting activities. However, this same dolphin was observed 30 minutes after the recorded jump, and behavior was documented as normal.

Comment 11:
Robbins
et al.
states that the take estimates in the ACOE's IHA application are faulty. The applicant assumes no behavioral modification in which the bottlenose dolphin avoids the blast area. By the applicant's admission contained in Table 4 of NMFS'
Federal Register
notice (76 FR 71352), the estimated take of bottlenose dolphins stock could be 0.162 per blasting event, and applying the 1,200 blasting events (two per day for 600 days), a total of 194 takes of bottlenose dolphins of the Biscayne Bay stock will occur. That means that 194 bottlenose dolphins (assuming that a single dolphin is subject to a take only once), then 84% of the Biscayne Bay stock will be subject to harassment. The analysis of the number of takes is faulty at 76 FR 71354. Because the ACOE IHA application is for only one year and does not consider the entire course of 600 blasts, nor does it consider the worst case in its own charts, it minimizes the impact, claiming only 12 of the Biscayne Bay stock of bottlenose dolphins will be taken (see 76 FR 71534). It is a disingenuous analysis and the percentages impacted are intentionally misleading. The NMFS
Federal Register
notice claims that “at worst [one year of blasting] may result, at worst in a temporary modification in behavior and/or low physiological effects (Level B harassment) of a small number of Atlantic bottlenose dolphins” (76 FR 71534). This conclusion is false and without the data and analysis to support it. Then, in the next sentence the NMFS
Federal Register
notice acknowledges that there may be “behavioral modifications” (76 FR 71534), but then claims that it will be just “temporary,” vacating the area immediately after the blasting “to avoid underwater acoustic disturbances,” however, there are no data and analysis to show that after days, weeks, and months of blasting, an intelligent mammal like a dolphin will not learn to avoid the area in its entirety, resulting in the splitting of the Biscayne Bay stock between the northern and southern portions of Biscayne Bay. “Behavioral reactions to noise exposure (such as disruption of critical life functions, displacement, or avoidance of important habitat) are more likely to be significant if they last more than one diel cycle or recur on subsequent days” (76 FR 71534). Does that not describe what is being proposed? Furthermore, the NMFS claims that the activities “will result in the incidental take of small numbers of marine mammals by Level B harassment only, and that the total taking from the blasting activities will have a negligible impact on the affected species or stocks of marine mammals” (76 FR 71534). This is utterly without support. As many as 84% of the Biscayne Bay stock of bottlenose dolphins would be impacted. Moreover, the functional severing of its habitat may affect behaviors from breeding to feeding to territorial behavior that have not been considered or analyzed.

Response:
The commenter incorrectly states the project will have 600 days of blasting. The ACOE estimates a maximum number of 313 blast days for the duration of this IHA (
i.e.,
365 days in a year minus 52 Sundays [normally no confined blasting is allowed on Sundays due to local ordinances]), with no more than one confined blast event at a time and no more than two confined blast events per a single day. A calendar day is 24 hours. A blast day/blast event (
i.e.,
approximately 1 hour 30 minutes in length) is the series of events beginning one hour before the detonation through 30 minutes after the detonation. There may be more than one blast day/blast event per calendar day, they will not occur simultaneously. NMFS and the ACOE disagree with the comment that the take estimates in the IHA application are faulty. Although the ACOE has calculated a total potential take of 45 bottlenose dolphins from the Biscayne Bay stock and 42 bottlenose dolphins from the Western North Atlantic Central Florida Coastal stock, these estimated take (87 total) were calculated without considering the implementation of monitoring and mitigation measures to protect marine mammals. By adding the layers of protection—(1) Confined blasting that reduces the pressure by up to 90%; (2) zones of protection based on open water detonations that give no credit for the pressure reduction previously mentioned; and (3) PSOs and aerial overflights; the ACOE and NMFS feel that these monitoring and mitigation measures reduce the potential for incidental take, and as a result the ACOE limited the take request (
i.e.,
a total of 22 bottlenose dolphins [12 from the Biscayne Bay stock and 10 from the Western North Atlantic Central Florida Coastal]) to the amounts cited in the
Federal Register
notice (76 FR 71517, November 18, 2011). See “Estimated Take by Incidental Harassment” section later in this document for more information on how the estimates of incidental takes of the two stocks of bottlenose dolphins were calculated.

Additionally, as previously stated in the response to Comment 9, bottlenose dolphins residing in or transiting through the vicinity of the Port of Miami are likely habituated to the presence and noise from commercial and recreational vessels, sea planes, and helicopters frequently in the action area, and have two locations within Biscayne Bay to transit between the northern and southern portions of the Biscayne Bay to avoid the ACOE's confined blasting and dredging operations, if necessary. Also, dolphins in the action area will have short exposure to the ACOE's confined blasting activities and it is unlikely that any particular animals would be in the small danger zone near the explosives long enough to be subjected to repeated exposures.

Comment 12:
Robbins
et al.
states that the ACOE's blasting area is immediately north and adjacent to the Bill Sadowski Critical Wildlife Area. The area adjacent to the Fisherman's Channel is a prime location to watch surfacing dolphins with their calves feeding during the hour before sunset. The proposed time of the blasts is one hour before sunset. The NMFS analysis of the incidental take does not consider the concentration

of marine mammals adjacent to and in the Bill Sadowski Critical Wildlife Area (76 FR 71532).

Response:
The ACOE is aware that the project borders the Bill Sadowski Critical Wildlife Area, however, a review of the NMFS SEFSC sighting data from 1990 to 2004 does not support the commenter's statement that the area adjacent to Fisherman's Channel has been identified as a prime habitat area for observing mother/calf pairs or groups in the hour before sunset. The data show the highest concentrations of dolphin sightings to be north of the Port of Miami near Baker's Haulover Inlet and south of Rickenbacker Causeway, west of Key Biscayne, neither of these areas are within the boundaries of the Bill Sadowski Critical Wildlife Area. This may be because the part of Biscayne Bay west of Key Biscayne and south of Rickenbacker Causeway may be quieter then the area immediately south of the Port of Miami. The commenters have provided no additional data to support their claim. Additionally, the ACOE's project specifications and NMFS' monitoring and mitigation measures in the IHA require that confined blast detonations be complete at least one hour before sunset, the ACOE does not say that this is when detonations occur.

Comment 13:
Robbins
et al.
states that the ACOE cannot obtain an IHA on the basis of its IHA application. The ACOE's project in the Port of Miami is expected to take up to 24 months and therefore requires development of regulations. The blasting and dredging project in the Port of Miami has been authorized in its entirety by the Federal and state governments (except for the MMPA incidental take authorization).

Despite clear statutory language, the ACOE and NMFS appear to take the position that the incidental take of marine mammals during the lengthy blasting and dredging phase could be covered under successive one-year IHAs. To the contrary, the specified activity of the deepening project in the Port of Miami can be considered for MMPA purposes only under regulations and the issuance of subsequent LOAs, as section 101(a)(5)(D) of the MMPA specifies that an IHA can be issued for “periods not more than one year.” The legislative history of the MMPA, case law, and NMFS' own practice in issuing IHAs and LOAs all point to the need for the ACOE to apply for a rule in this context.

NMFS must administer the MMPA for the “benefit of the protected species rather than for the benefit of commercial exploitation.”
Committee for Human Legislation
v.
Richardson,
540 F.2d 1141, 1148 (1976) (citing H.R. Rep. No. 92-707). And any decision “must be consistent with the MMPA immediate goal” of reducing take or serious injury to marine mammals to “insignificant levels approaching zero mortality and serious injury rate.”
Kokechik Fishermen's Ass'n
v.
Sec'y of Commerce,
839 F.2d 795, 801 (1988) (citing 16 U.S.C. 1371(a)(2)). Congress' intent was to “insist that the management of the animal populations be carried out with the interests of the animals as the prime consideration.” H.R. Rep. No. 92-707, at 18. Therefore, the Secretary of Commerce must first look at the “interest in maintaining healthy populations of marine mammals” when balancing competing interests. Id. At 802;
Committee for Humane Legislation,
v.
Richardson,
540 F.2d at 1151 n.39; see H.R. Rep. No.92-707, at 24 (1971) (The House Merchant Marine and Fisheries Committee intended to “build such a conservative bias into the [MMPA]”); 118 Cong. Rec. S. 15680 (daily ed. October 4, 1971) (statement of Sen. Packwood) (“Scientists generally will state that our level of knowledge of marine mammals is very low * * * Barring better and more information, it would therefore appear to be wise to adopt a cautious attitude toward the exploitation of marine mammals.”).

When these principles are applied, NMFS must adopt an interpretation of its section 101(a)(5) incidental take authority that recognizes the one-year limitation applied to IHAs and apply regulations (and subsequent LOA) requirements. Any other approach will fail to give sufficient protection to the many marine mammals that will be subjected to take and harassment in favor of expediting the development of the Port of Miami blasting and dredging project. NMFS cannot allow for such a result and must deny the ACOE's IHA application.

The choice of incidental take authorization is very important because it has consequences for the protection provided to marine mammals and the level of public involvement. An IHA will consider only the takes that occur over the course of one year to determine whether the impacts of the “specified activity” on marine mammals are negligible. An activity like the Port of Miami blasting and dredging operations will occur continuously over several years and will have greater impacts when considered in its entirety than it will for just a component of the activity conducted during a single year. To determine if there is a “negligible impact,” it is therefore necessary to consider the entire activity, not just a subset of the activity defined by one-year increments.

Response:
NMFS disagrees with the commenter's statement. The ACOE has requested an IHA in its adequate and complete application. 50 CFR 216.107 states that except for activities that have the potential to result in serious injury or mortality, which must be authorized under § 216.105, IHAs may be issued, following a 30-day public review period, to allowed activities that may result in only the incidental harassment of a small number of marine mammals. Each such IHA shall set forth permissible methods of taking by harassment; means of effecting the least practicable impact on the species, its habitat, and on the availability of the species for subsistence uses; and requirements for monitoring and reporting. IHAs will be valid for a period of time not to exceed one year but may be renewed for additional periods of time not to exceed one year for each reauthorization; therefore, the promulgation of regulations and the subsequent issuance of LOAs to the ACOE for the confined blasting operations in the Port of Miami is not necessary or required. NMFS has issued IHAs under section 101(a)(5)(D) of the MMPA for “periods not more than one year” and renewed IHAs, upon request for applicant's conducting specified activities that have the potential to result in the incidental harassment (Level A and/or Level B harassment) of small numbers of marine mammals. Specified activities that have the potential to result in serious injury or mortality of marine mammals must be authorized under 50 CFR 216.106. For additional information, please see the response to Comment 1.

Per requirements of 50 CFR 216.104, the ACOE included the necessary information for their activity in its submission to NMFS requesting an IHA. NMFS worked with the ACOE and requested additional information in its original IHA application to ensure and determine, based upon the best available scientific evidence, that it was adequate and complete. For the proposed IHA (76 FR 71517, November 18, 2011), NMFS invited information, suggestions, and comments from the public for a period not to exceed 30 days from the date of publication in the
Federal Register
. NMFS will involve the public on a proposed IHA, if or when the ACOE requests a renewal of the IHA for confined blasting operations as part of the Miami Harbor Deepening Project. The cumulative impacts of the ACOE's multiple year activities are considered and analyzed in the ACOE's FEIS and NMFS's EA.

Comment 14:
Robbins
et al.
states that the mitigation efforts are insufficient and detrimental to the bottlenose dolphin. The issue of necessity for blasting and the amount of blasting involved in the blasting and dredging project in the Port of Miami does not appear to have been revisited. Technological advances in dredging equipment that would reduce the amount of blasting needed would greatly minimize the adverse effects on all marine life in and around the project footprint. As this project takes place within an Aquatic Preserve, classified as an Outstanding Florida Water, adjacent to a critical wildlife area, and is considered habitat for over 12 endangered or threatened species of marine life, it is imperative the most updated and least impactful best management practices be employed, including the most recent machinery, scientific studies and mitigation practices.

Response:
As previously discussed in the response to Comment 5, it is unclear why the commenter believes that protective monitoring and mitigation measures proposed by the ACOE and required in the IHA issued by NMFS are detrimental to the bottlenose dolphins. NMFS has determined that the monitoring and mitigation measures required by the IHA will ensure the specified activity will have the least practicable impact on the stocks of bottlenose dolphins in the action area. The commenter contends that technological advances in dredging equipment would reduce the amount of blasting. During the feasibility and EIS process, ACOE reviewed all of the geotechnical data collected over the last 20 years. The ACOE's geotechnical engineers determined that the rock in Miami Harbor is both hard and massive, and will require pretreatment before removal with any dredging technology currently available.

The only methods available for pre-treatment of hard/massive rock are confined blasting and the use of a punch-barge or hydrohammer. As part of the feasibility and EIS process, the ACOE consulted with NMFS and the USFWS under section 7 of the ESA to determine the impacts of both methods on listed and protected species in the action area. NMFS and USFWS have both documented that the use of a punch-barge or hydrohammer, which would work during daylight hours, strikes the rock approximately once every 60 seconds for up to 720 hits in a 12 hour period. This would increase during periods of extended daylight. This constant pounding would serve to disrupt animal behavior in the area. Using the punch-barge would also extend the length of the project, thus increasing any potential impacts to all fish and wildlife resources in the action area. The ACOE believes that confined blasting to remove the rock in the Port of Miami has the least environmental impact of all available methods. Utilization of a punch-barge would result in pressure being released into the water like an unconfined blast, without a reduction in associated pressure wave, which can lead to impacts to marine mammals, and fish kill at levels much higher than confined underwater blasting. The ACOE removed punch-barging as a viable pre-treatment methodology, which leaves confined blasting as the only method to pre-treat rock prior to removal by conventional dredging methodologies.

NMFS' SERO issued a Biological Opinion (BiOp) on September 8, 2011, that analyzes the project's effects on staghorn coral (
Acropora cervicornis
). It is NMFS' biological opinion that the action, is likely to adversely affect staghorn coral, but is not likely to jeopardize its continued existence or destroy or adversely modify its designated critical habitat. Based upon NMFS SERO's analysis, NMFS no longer expects the project is likely to adversely affect Johnson's seagrass (
Halophila johnsonii
) or its designated critical habitat. NMFS has determined that the ESA-listed marine mammals (Blue, fin, sei, humpback, North Atlantic right, and sperm whales), smalltooth sawfish (
Pristis pectinata
), and leatherback sea turtles (
Dermochelys coriacea
) are not likely to be adversely affected by the action (NMFS, 2011). The USFWS concurred with the ACOE's determination that the construction activities related to the modification of Miami Harbor to accommodate the expansion of the Port of Miami may affect, but are not likely to adversely affect the West Indian manatee and the American crocodile since appropriate monitoring to minimize these effects will be incorporated into the project design. In addition, the effects of the action will not result in the adverse modification to designated critical habitat for the West Indian manatee if sufficient mitigation is provided for seagrass impacts (USFWS, 2003). See the Endangered Species Act section below for more information on endangered or threatened species.

Comment 16:
Robbins
et al.
states that NMFS should require improvement for zones and the monitoring program. Zone calculations should use the latest studies and incorporate all findings from prior blasting events and account for bathymetric data and the nature of the blast area (
i.e.,
channels). A report entitled “Blast emission criteria and detection methods for the safeguarding of marine mammals in a blast environment” by R. A. Godson, published in 2010, states the following criteria:

In order to provide an objective and quantitative assessment of the range and severity of any environmental effect from underwater blasting, it is necessary to be able to estimate the following parameters: The source level (
i.e.,
level of sound) generated by the explosives; the transmission loss, that is, the rate at which sound from the source is attenuated as it propagates underwater; the effect threshold, that is, the level of sound at which a particular effect, such as death, injury or avoidance of a species, occurs * * * (page 684).

The Safety Zone is the zone beyond which peak pressure levels from blasting are predicted to be lower than the 83 kPa criterion, creating no adverse effects on marine mammals * * * This criterion was originally established for estimating the impacts of large unconfined explosions and was introduced in order to provide a more conservative range * * * when explosive or the marine animal approaches the sea surface (for which cases the explosive energy is reduced but the peak pressure is not) (page 686).

The report further specifies the determination of the safety zone radius:

The Safety Zone is the zone beyond which peak pressure levels from blasting are predicted to be lower than the 83 kPa criterion, creating no adverse effects * * * The propagation of the peak pressure is very much dependent on the hydrography specific to the site, the water depth and the sound propagation underwater (page 686).

The ACOE's IHA application frequently cites its 2005 blasting activities as a point of reference for the proposed blasting activities in 2012. These projects do not warrant the comparison, especially for the incidental take of dolphins as the ACOE contends. The project footprint is far larger in the present project than in 2005. The maximum weight of explosives has increased from 376 lbs (76 FR 71519) to 450 lbs with averages of two blasts per day for an estimated 600 days of blasting. Although, in its proposed calculations, ACOE has increased the danger zone for dolphins by 500 ft, this is insufficient accommodation relative to the large increase in blast pressure due to increased weight and frequency of blasting. Further, the safety zone calculation has not changed from the past blasting event in the current application. As detailed above, the safety zone is a critical component to ensure marine mammal safety.

Despite an incident during a 2005 blast reported in the “Protected Marine

Species Watch Program Miami Harbor Deepening Project” by ECOES Consulting, Inc. for the ACOE, the ACOE has not altered its mitigation program based on these findings. As stated in the report, two dolphins located in the channel west of the blasting, stationary at approximately 2,400 ft, “were feeding and cavorting.” The exclusion zone calculation was 1,600 ft for the lower weight of explosives used that day (the exact weight used is not recorded in this report). The report continues to describe the channel area (where much of the proposed blasting will also occur):

The topography of the bottom of that area is very much shallow to the south, then an exceptionally steep drop off into the channel at 40+ ft ending at the bulkhead wall to the north. Westward, the channel continues and has a more gradual upward slope. At the time of the blast, one of the dolphins was at the surface in the shallows, which the other dolphin was underwater within the channel. The dolphin that was underwater showed a strong reaction to the blast. The animal jumped fully out of the water in a “breaching” fashion; behavior that had not been exhibited prior to the blast (ECOES, p. 18).

It is critical to note that based on the ACOE formula (which is proposed to remain the same in the current IHA application), the harassed dolphin was located 800 ft outside of the exclusion zone and still exhibited a strong adverse reaction to the blast described as “lower weight.” Considering the significant increase in weight maximum in the current project and the much increased frequency and duration of this project, it is clear that the mitigation and zone calculations are insufficient as proposed. In the ECOES report conclusion, the author also notes that the shallow channel and bathymetry of the project site, which remains the same (only expanded) in the current project has a great effect on the pressure and sound effect of the blasting agents: “This observation may be important to consider when formulating blast/watch plans for marine mammals in the future. It may be prudent to extend or contract the exclusion zone based on the bathymetry of the project site” (ECOES, p. 18).

Response:
The commenter incorrectly states the project will have 600 days of blasting. The ACOE estimates a maximum number of 313 blast days for the duration of this IHA (
i.e.,
365 days in a year minus 52 Sundays [normally no confined blasting is allowed on Sundays due to local ordinances]), with no more than one confined blast event at a time and no more than two confined blast events per a single day. A calendar day is 24 hours. A blast day/blast event (
i.e.,
approximately 1 hour 30 minutes in length) is the series of events beginning one hour before the detonation through 30 minutes after the detonation. There may be more than one blast day/blast event per calendar day, they will not occur simultaneously.

The commenter recommends that NMFS and the ACOE adopt the model proposed in Godson (2010) and believes that Godson's report entitled “Blast emission criteria and detection methods for safeguarding of marine mammals in a blast environment” presents the most recent data available (
i.e.,
the best scientific evidence) concerning underwater blasting. This is incorrect. Godson states that his model is based on a “comprehensive review of different underwater blasting propagation models for a recent underwater blasting impacts assessment study” found in Godson (2005). This means he did not review the most recent pressure studies and models developed from the data collected after the Kill van Kull blasting was completed in 2004, particularly the data collected in 2005 at Miami Harbor and published in Hempen
et al.
(2007).

The Godson model utilizes an unconfined blast as is demonstrated by its use of −1.13 exponential in the model equation. The −1.13 exponential utilized in the blasting literature is the attenuation, or reduction, of the maximum pressure through water. This is not an accurate representation of the effects from the proposed confined blasting at Miami Harbor. Based on the in situ pressure measurements collected in 2005, the ACOE's blasting experts developed a similar model to assess the benefit of confinement of the blast, however, even with the knowledge that confinement of the detonation in rock significantly reduces the pressure wave (Hempen
et al.,
2007; Hempen
et al.,
2005; Nedwell and Thandavamoorthy, 1992), the ACOE opted not to give any credit to the reduction in maximum pressure. By opting not to incorporate the reduction in maximum pressure into the protective zone equations, the ACOE is being conservative and protective of marine mammals in and near the action area.

Comment 15:
The Commission recommends that NMFS issue the IHA, provided it requires the ACOE to conduct empirical sound propagation measurements during two detonation events per day using various delay weights and numbers of delays to verify that the danger and exclusion zones are sufficient to protect marine mammals from sound exposure levels, including the 182 and 177 dB re 1 Pa
2
s thresholds. If the zones are found to be too small, then NMFS and ACOE should adjust them accordingly. In addition, NMFS and the ACOE should use the distances to the relevant thresholds from those empirical measurements to estimate the number of takes for subsequent IHAs.

Response:
The ACOE is unable to collect data on empirical sound propagation measurements as recommended by the Commission because the area immediately south of Fisherman's Channel is bounded by shallow seagrass beds and encompassed by the Bill Sadowski Critical Wildlife Area. The shallow seagrass beds are found in waters so shallow that seagrasses are often exposed at low tides and motoring through the area would adversely impact the seagrass beds by dredging prop scars into the beds, resulting in previously unanticipated impacts. Additionally, Florida state law prohibits motorized vessels from entering this area.

To be able to collect the data requested by the Commission, the ACOE's contractor would have to lay out a network of hydrophones or pressure transducers before each blast, which requires entering the Bill Sadowski Critical Wildlife Area to lay the hydrophones or pressure transducers with a motorized vessel, and repeat the process to recover them after each blast, or it would require the ACOE to set up a network of vessels in the boundaries of the Bill Sadowski Critical Wildlife Area with a hydrophone or pressure transducer on each vessel. Hydrophone equipment systems have limitations gathering peak pressure data from blasting, and can be quickly overloaded if placed too close to the detonation; pressure transducers are better designed to measure blast pressures (Keevin, pers. comm.). Again, the vessels would have to enter the Bill Sadowski Critical Wildlife Area, which is in violation of the previously mentioned state law.

Comment 16:
The Commission recommends that NMFS issue the IHA, provided it requires the ACOE to suspend all activities if the authorized number of takes is reached.

Response:
NMFS concurs with the Commission's recommendation and has included a condition to this effect in the IHA. The taking by injury (Level A harassment), serious injury, or mortality of Atlantic bottlenose dolphins or any other species of marine mammal is prohibited and may result in the modification, suspension, or revocation of the IHA. If the ACOE exceeds the authorized number of takes, then the ACOE will notify NMFS and the IHA may be modified.

Description of Marine Mammals in the Area of the Specified Activity

Several cetacean species and a single species of sirenian are known to or could occur in the Miami Harbor action area and off the Southeast Atlantic coastline (see Table 1 below). Species listed as endangered under the U.S. Endangered Species Act (ESA), includes the humpback (
Megaptera novaeangliae
), sei (
Balaenoptera borealis
), fin (
Balaenoptera physalus
), blue (
Balaenoptera musculus
), North Atlantic right (
Eubalaena glacialis
), and sperm (
Physeter macrocephalus
) whale, and West Indian (Florida) manatee

(
Trichechus manatus

latirostris
). The marine mammals that occur in the Atlantic Ocean off the U.S. southeast coast belong to three taxonomic groups: mysticetes (baleen whales), odontocetes (toothed whales), and sirenians (the manatee). The West Indian manatee in Florida and U.S. waters is managed under the jurisdiction of the USFWS and therefore is not considered further in this analysis.

Table 1 below outlines the marine mammal species and their habitat in the region of the project area.

Table 1—The Habitat and Conservation Status of Marine Mammals Inhabiting the Project Area in the Atlantic Ocean off the U.S. Southeast Coast

Species
Habitat

ESA
1

MMPA
2

Mysticetes:

North Atlantic right whale (
Eubalaena glacialis
)

Coastal and shelf
EN
D

Humpback whale (
Megaptera novaeangliae
)

Pelagic, nearshore waters, and banks
EN
D

Bryde's whale (
Balaenoptera brydei
)

Pelagic and coastal
NL
NC

Minke whale (
Balaenoptera acutorostrata
)

Shelf, coastal, and pelagic
NL
NC

Blue whale (
Balaenoptera musculus
)

Pelagic and coastal
EN
D

Sei whale (
Balaenoptera borealis
)

Primarily offshore, pelagic
EN
D

Fin whale (
Balaenoptera physalus
)

Slope, mostly pelagic
EN
D

Odontocetes:

Sperm whale (
Physeter macrocephalus
)

Pelagic, deep seas
EN
D

Cuvier's beaked whale (
Ziphius cavirostris
)

Pelagic
NL
NC

Gervais' beaked whale (
Mesoplodon europaeus
)

Pelagic
NL
NC

True's beaked whale (
Mesoplodon mirus
)

Pelagic
NL
NC

Blainville's beaked whale (
Mesoplodon densirostris
)

Pelagic
NL
NC

Dwarf sperm whale (
Kogia sima
)

Offshore, pelagic
NL
NC

Pygmy sperm whale (
Kogia breviceps
)

Offshore, pelagic
NL
NC

Killer whale (
Orcinus orca
)

Widely distributed
NL EN (Southern Resident)
NC D (Southern Resident, AT1 Transient)

Short-finned pilot whale (
Globicephala macrorhynchus
)

Inshore and offshore
NL
NC

False killer whale (
Pseudorca crassidens
)

Pelagic
NL
NC

Mellon-headed whale (
Peponocephala electra
)

Pelagic
NL
NC

Pygmy killer whale (
Feresa attenuata
)

Pelagic
NL
NC

Risso's dolphin (
Grampus griseus
)

Pelagic, shelf
NL
NC

Bottlenose dolphin (
Tursiops truncatus
)

Offshore, Inshore, coastal, and estuaries
NL
NC S (Biscayne Bay and Central Florida Coastal stocks) D (Western North Atlantic Coastal)

Rough-toothed dolphins (
Steno bredanensis
)

Pelagic
NL
NC

Fraser's dolphin (
Lagenodelphis hosei
)

Pelagic
NL
NC

Striped dolphin (
Stenella coeruleoalba
)

Pelagic
NL
NC

Pantropical spotted dolphin (
Stenella attenuata
)

Pelagic
NL
NC D (Northeastern Offshore)

Atlantic spotted dolphin (
Stenella frontalis
)

Coastal to pelagic
NL
NC

Spinner dolphin (
Stenella longirostris
)

Mostly pelagic
NL
NC D (Eastern)

Clymene dolphin (
Stenella clymene
)

Pelagic
NL
NC

Sirenians:

West Indian (Florida) manatee (
Trichechus manatu
s
latirostris
)

Coastal, rivers, and estuaries
EN
D

1
U.S. Endangered Species Act: EN = Endangered, T = Threatened, NL = Not listed.

2
U.S. Marine Mammal Protection Act: D = Depleted, S = Strategic, NC = Not classified.

The one species of marine mammal under NMFS jurisdiction known to commonly occur in close proximity to the blasting area of the Port of Miami is the Atlantic bottlenose dolphin, specifically the stocks living near the Port of Miami within Biscayne Bay (the Biscayne Bay stock) or transiting the outer entrance channel (Western North Atlantic Central Florida Coastal stock).

Atlantic Bottlenose Dolphin

Atlantic bottlenose dolphins are distributed worldwide in tropical and temperate waters, and in U.S. waters occur in multiple complex stocks along

the U.S. Atlantic coast. The coastal morphotype of bottlenose dolphins is continuously distributed along the Atlantic coast south of Long Island, New York, to the Florida peninsula, including inshore waters of the bays, sounds, and estuaries. Except for animals residing within the Southern North Carolina and Northern North Carolina Estuarine Systems (
e.g.,
Waring
et al.,
2009), estuarine dolphins along the U.S. east coast have not been previously included in stock assessment reports. Several lines of evidence support a distinction between dolphins inhabiting coastal waters near the shore and those present in the inshore waters of the bays, sounds, and estuaries. Photo-ID and genetic studies support the existence of resident estuarine animals in several inshore areas of the southeastern United States (Caldwell, 2001; Gubbins, 2002; Zolman, 2002; Mazzoil
et al.,
2005; Litz, 2007), and similar patterns have been observed in bays and estuaries along the Gulf of Mexico coast (Well
et al.,
1987; Balmer
et al.,
2008). Recent genetic analyses using both mitochondrial DNA and nuclear microsatellite markers found significant differentiation between animals biopsied along the coast and those biopsied within the estuarine systems at the same latitude (NMFS, unpublished data). Similar results have been found off the west coast of Florida (Sellas
et al.,
2005).

Biscayne Bay Stock

Biscayne Bay is a shallow estuarine system located along the southeast coast of Florida in Miami-Dade County. The Bay is generally shallow (depths less than 5 m [16.4 ft]) and includes a diverse range of benthic communities including seagrass beds, soft coral and sponge communities, and mud flats. The northern portion of Biscayne Bay is surrounded by the cities of Miami and Miami Beach and is therefore heavily influenced by industrial and municipal pollution sources. The water flow in this portion of Biscayne Bay is very restricted due to the construction of dredged islands (Bialczak
et al.,
2001). In contrast, the central and southern portions of Biscayne Bay are less influenced by development and are better flushed. Water exchange with the Atlantic Ocean occurs through a broad area of grass flats and tidal channels termed the Safety Valve. Biscayne Bay extends south through Card Sound and Barnes Sound, and connects through smaller inlets to Florida Bay.

The Biscayne Bay stock of bottlenose dolphins is bounded by Haulover Inlet to the north and Card Sound Bridge to the south. This range corresponds to the extent of confirmed home ranges of bottlenose dolphins observed residing in Biscayne Bay by a long-term photo-ID study conducted by the Southeast Fisheries Science Center (Litz, 2007; SEFSC unpublished data). It is likely that the range of Biscayne Bay dolphins extends past these boundaries; however, there have been few surveys outside of this range. These boundaries are subject to change upon further study of dolphin home ranges within the Biscayne Bay estuarine system and comparison to an extant photo-ID catalog from Florida Bay to the south.

Dolphins residing within estuaries north of this stock along the southeastern coast of Florida are currently not included in a stock assessment report. There are insufficient data to determine whether animals in this region exhibit affiliation to the Biscayne Bay stock, the estuarine stock further to the north in the IRLES, or are simply transient animals associated with coastal stocks. There is relatively limited estuarine habitat along this coastline; however, the Intracoastal Waterway extends north along the coast to the IRLES. It should be noted that during 2003 to 2007, there were three stranded bottlenose dolphins in this region in enclosed waters. One of these had signs of human interaction from a boat strike and another was identified as an offshore morphotype of bottlenose dolphin.

Bottlenose dolphins have been documented in Biscayne Bay since the 1950's (Moore, 1953). Live capture fisheries for bottlenose dolphins are known to have occurred throughout the southeastern U.S. and within Biscayne Bay during the 1950's and 1960's; however, it is unknown how many individuals may have been removed from the population during this period (Odell, 1979; Wells and Scott, 1999).

The Biscayne Bay bottlenose dolphin stock has been the subject of an ongoing photo-ID study conducted by the NMFS SEFSC since 1990. From 1990 to 1991, preliminary information was collected focusing on the central portion of Biscayne Bay. The survey was re-initiated in 1994, and it was expanded to include the northern portion of Biscayne Bay and south to the Card Sound Bridge in 1995 (SEFSC unpublished data; Litz, 2007). Through 2007, the photo-ID catalog included 229 unique individuals. Approximately 80% of these individuals may be long-term residents with multiple sightings over the 17 years of the study (SEFSC, unpublished data). Analyses of the sighting histories and associations of individuals from the Biscayne Bay segregated along a north/south gradient (Litz, 2007).

Remote biopsy samples of Biscayne Bay animals were collected between 2002 and 2004 for analyses of population genetic structure and persistent organic pollutant concentrations in blubber. Genetic structure was investigated using both mitochondrial DNA and nuclear (microsatellite) markers, and the data from Biscayne Bay were compared to data from Florida Bay dolphins to the south (Litz, 2007). Within Biscayne Bay, dolphins sighted primarily in the northern half of Biscayne Bay were significantly differentiated from those sighted primarily in the southern half at the microsatellite loci but not at the mitochondrial locus. There was not sufficient genetic information between these groups to indicate true population subdivision (Litz, 2007). However, genetic differentiation was found between the Biscayne Bay and Florida Bay dolphins in both markers (Litz, 2007). The observed genetic differences between resident animals in Biscayne Bay and those in an adjacent estuary combined with the high levels of sight fidelity observed, demonstrate that the resident Biscayne Bay bottlenose dolphins are a demographically distinct population stock.

The total number of bottlenose dolphins in the Biscayne Bay stock is unknown. During small boat surveys between 2003 and 2007, 157 unique individuals were identified using standard methods, however, this catalog size does not represent a valid estimate of population size because the residency patterns of dolphins in Biscayne Bay is not fully understood. Litz (2007) determined that 69 animals in Biscayne Bay have a northern home range. Based on Waring
et al.
(2010), the maximum population of animals that may be in the project area is equal to the total number of uniquely identified animals for the entire photo-ID study of Biscayne Bay—229 individuals. Present data are insufficient to calculate a minimum population estimate, and to determine the population trends, for the Biscayne Bay stock of bottlenose dolphins. The total human-caused mortality and serious injury for this stock is unknown and there is insufficient information available to determine whether the total fishery-related mortality and serious injury for this stock is insignificant and approaching zero mortality and serious injury rate. Documented human-caused mortalities in recreational fishing gear entanglement and ingestion of gear reinforce concern for this stock. Because the stock size is currently unknown, but likely small and relatively few

mortalities and serious injuries would exceed potential biological removal, NMFS considers this stock to be a strategic stock.

Western North Atlantic Central Florida Coastal Stock

On the Atlantic coast, Scott
et al.
(1988) hypothesized a single coastal migratory stock ranging seasonally from as far north as Long Island, to as far south as central Florida, citing stranding patterns during a high mortality event in 1987 to 1988 and observed density patterns. More recent studies demonstrate that the single coastal migratory stock hypothesis is incorrect, and there is instead a complex mosaic of stocks (McLellan
et al.,
2003; Rosel
et al.,
2009).

The coastal morphotype is morphologically and genetically distinct from the larger, more robust morphotype primarily occupying habitats further offshore (Hoelzel
et al.,
1998; Mead and Potter, 1995; Rosel
et al.,
2009). Aerial surveys conducted between 1978 and 1982 (CETAP, 1982) north of Cape Hatteras, North Carolina, identified two concentrations of bottlenose dolphins, one inshore of the 82 ft (25 m) isobath and the other offshore of the 164 ft (50 m) isobath. The lowest density of bottlenose dolphins was observed over the continental shelf, with higher densities along the coast and near the continental shelf edge. It was suggested, therefore, that north of Cape Hatteras, North Carolina, the coastal morphotype is restricted to waters less than 82 ft deep (Kenney, 1990). Similar patterns were observed during summer months in more recent aerial surveys (Garrison and Yeung, 2001; Garrison
et al.,
2003). However, south of Cape Hatteras during both winter and summer months, there was no clear longitudinal discontinuity in bottlenose dolphin sightings (Garrison and Yeung 2001; Garrison
et al.,
2003). To address the question of distribution of coastal and offshore morphotypes in waters south of Cape Hatteras, tissue samples were collected from large vessel surveys during the summers of 1998 and 1999, from systematic biopsy sampling efforts in nearshore waters from New Jersey to central Florida conducted in the summers of 2001 and 2002, and from winter biopsy collection effort in 2002 and 2003 in nearshore continental shelf waters of North Carolina and Georgia. Additional biopsy samples were collected in deeper continental shelf waters south of Cape Hatteras during the winter of 2002. Genetic analyses using mitochondrial DNA sequences of these biopsies identified individual animals to the coastal or offshore morphotype. Using the genetic results from all surveys combined, a logistic regression was used to model the probability that a particular bottlenose dolphin group was of the coastal morphotype as a function of environmental variables including depth, sea surface temperature, and distance from shore. These models were used to partition the bottlenose dolphin groups observed during aerial surveys between the two morphotypes (Garrison
et al.,
2003).

The genetic results and spatial patterns observed in aerial surveys indicate both regional and seasonal differences in the longitudinal distribution of the two morphotypes in coastal Atlantic waters. Generally, from biopsy samples collected, the coastal morphotype is found in nearshore waters, the offshore morphotype in deeper waters and a spatial overlap between the two morphotypes in intermediate waters. More information on the seasonal differences and genetic studies off of the Carolina's, Georgia, and Florida, differentiating morphotypes of bottlenose dolphins can be found online in the NMFS stock assessment reports.

In summary, the primary habitat of the coastal morphotype of bottlenose dolphin extends from Florida to New Jersey during summer months and in waters less than 65.6 ft (20 m) deep, including estuarine and inshore waters.

In addition to inhabiting coastal nearshore waters, the coastal morphotype of bottlenose dolphin also inhabits inshore estuarine waters along the U.S. east coast and Gulf of Mexico (Wells
et al.,
1987; Wells
et al.,
1996; Scott
et al.,
1990; Weller, 1998; Zolman, 2002; Speakman
et al.,
2006; Stolen
et al.,
2007; Balmer
et al.,
2008; Mazzoil
et al.,
2008). There are multiple lines of evidence supporting demographic separation between bottlenose dolphins residing within estuaries along the Atlantic coast. In Biscayne Bay, Florida, there is a similar community of bottlenose dolphins with evidence of year-round residents that are genetically distinct from animals residing in a nearby estuary in Florida Bay (Litz, 2007). A few published studies demonstrate that there are significant genetic distinctions and differences between animals in nearshore coastal waters and estuarine waters (Caldwell, 2001; Rosel
et al.,
2009). Despite evidence for genetic differentiation between estuarine and nearshore populations, the degree of spatial overlap between these populations remains unclear. Photo-ID studies within estuaries demonstrate seasonal immigration and emigration and the presence of transient animals (
e.g.,
Speakman
et al.,
2006). In addition, the degree of movement of resident estuarine animals into coastal waters on seasonal or shorter time scales is poorly understood. However, for the purposes of this analysis, bottlenose dolphins inhabiting primarily estuarine habitats are considered distinct from those inhabiting coastal habitats. Initially, a single stock of coastal morphotype bottlenose dolphins was thought to migrate seasonally between New Jersey (summer months) and central Florida based on seasonal patterns in strandings during a large scale mortality event occurring during 1987 to 1988 (Scott
et al.,
1988). However, re-analysis of stranding data (McLellan
et al.,
2003) and extensive analysis of genetic (Rosel
et al.,
2009), photo-ID (Zolman, 2002) and satellite telemetry (NMFS, unpublished data) data demonstrate a complex mosaic of coastal bottlenose dolphin stocks. Integrated analysis of these multiple lines of evidence suggests that there are five coastal stocks of bottlenose dolphins: the Northern Migratory and Southern Migratory stocks, a South Carolina/Georgia Coastal stock, a Northern Florida Coastal stock, and a Central Florida Coastal stock.

The spatial extent of these stocks, their potential seasonal movements, and their relationships with estuarine stocks are poorly understood. More information on the migratory movements and genetic analyses of bottlenose dolphins can be found online in the NMFS stock assessment reports.

The NMFS stock assessment report addresses the Central Florida Coastal stock, which is present in coastal Atlantic waters from 29.4° North south to the western end of Vaca Key (approximately 24.69° North to 81.11° West) where the stock boundary for the Florida Keys stock begins (see Figure 1 of the NMFS Stock Assessment Report). There has been little study of bottlenose dolphin stock structure in coastal waters of southern Florida; therefore the southern boundary of the Central Florida stock is uncertain. There is no obvious boundary defining the offshore extent of this stock. The combined genetic and logistic regression analysis (Garrison
et al.,
2003) indicated that in waters less than 32.8 ft (10 m) depth, 70% of the bottlenose dolphins were of the coastal morphotype. Between 32.8 ft and 65.6 ft depth, the percentage of animals of the coastal morphotype dropped precipitously, and at depths greater than 131.2 ft (40 m) nearly all (greater than 90%) animals were of the offshore morphotype. These spatial patterns may not apply in the Central Florida Coastal stock, as there is a

significant change in the bathymetric slope and a close approach of the Gulf Stream to the shoreline south of Cape Canaveral.

Aerial surveys to estimate the abundance of coastal bottlenose dolphins in the Atlantic were conducted during winter (January to February) and summer (July to August) of 2002. Abundance estimates for bottlenose dolphins in each stock were calculated using line-transect methods and distance analysis (Buckland
et al.,
2001). More information on the survey tracklines, design, effort, animals sighted, and methods for calculating estimated abundance can be found online in the NMFS stock assessment reports.

The estimated best and minimum population for the Central Florida Coastal Stock is 6,318 and 5,094 animals, respectively. There are insufficient data to determine the population trends for this stock. From 1995 to 2001, NMFS recognized only a single migratory stock of coastal bottlenose dolphins in the western North Atlantic, and the entire stock was listed as depleted. This stock structure was revised in 2002 to recognize both multiple stocks and seasonal management units and again in 2008 and 2010 to recognize resident estuarine stocks and migratory and resident coastal stocks. The total U.S. fishery-related mortality and serious injury for the Central Florida Coastal stock likely is less than 10% of the calculated PBR, and thus can be considered to be insignificant and approaching zero mortality and serious injury rate. However, there are commercial fisheries overlapping with this stock that have no observer coverage. This stock retains the depleted designation as a result of its origins from the originally delineated depleted coastal migratory stock. The species is not listed as threatened or endangered under the ESA, but this is a strategic stock due to the depleted listing under the MMPA.

Further information on the biology and local distribution of these species and others in the region can be found in ACOE's IHA application, which is available upon request (see
ADDRESSES
), and the NMFS Marine Mammal Stock Assessment Reports, which are available online at:
http://www.nmfs.noaa.gov/pr/species/
.

Potential Effects on Marine Mammals

In general, potential impacts to marine mammals from explosive detonations could include mortality, serious injury, as well as Level A harassment (injury) and Level B harassment. In the absence of mitigation, marine mammals could be killed or injured as a result of an explosive detonation due to the response of air cavities in the body, such as the lungs and bubbles in the intestines. Effects would be likely to be most severe in near surface waters where the reflected shock wave creates a region of negative pressure called “cavitation.”

A second potential possible cause of mortality (in the absence of mitigation) is the onset of extensive lung hemorrhage. Extensive lung hemorrhage is considered debilitating and potentially fatal. Suffocation caused by lung hemorrhage is likely to be the major cause of marine mammal death from underwater shock waves. The estimated range for the onset of extensive lung hemorrhage to marine mammals varies depending upon the animal's weight, with the smallest mammals having the greatest potential hazard range.

NMFS' criteria for determining potential for non

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2012-19460. Public record. Not legal advice.