Injurious Wildlife Species; Listing 10 Freshwater Fish and 1 Crayfish

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DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 16 RIN 1018-AY69 [Docket No. FWS-HQ-FAC-2013-0095; FXFR13360900000-156-FF09F14000] Injurious Wildlife Species; Listing 10 Freshwater Fish and 1 Crayfish AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule.

SUMMARY:

The U.S. Fish and Wildlife Service (Service) proposes to amend its regulations to add to the list of injurious fish the following freshwater fish species: Crucian carp ( Carassius carassius ), Eurasian minnow ( Phoxinus phoxinus ), Prussian carp ( Carassius gibelio ), roach ( Rutilus rutilus ), stone moroko ( Pseudorasbora parva ), Nile perch ( Lates niloticus ), Amur sleeper ( Perccottus glenii ), European perch ( Perca fluviatilis ), zander ( Sander lucioperca ), and wels catfish ( Silurus glanis ). In addition, the Service also proposes to amend its regulations to add the freshwater crayfish species common yabby ( Cherax destructor ) to the list of injurious crustaceans. These listings would prohibit the importation of any live animal, gamete, viable egg, or hybrid of these 10 fish and 1 crayfish into the United States, except as specifically authorized. These listings would also prohibit the interstate transportation of any live animal, gamete, viable egg, or hybrid of these 10 fish and 1 crayfish between the States, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States, except as specifically authorized. As proposed, these species are injurious to human beings, to the interests of agriculture, or to wildlife or the wildlife resources of the United States, and the listing will prevent the purposeful or accidental introduction and subsequent establishment of these 10 fish and 1 crayfish into ecosystems of the United States. We are also making available for public review and comment the associated draft environmental assessment and draft economic analysis for this action

ts of agriculture, or to wildlife or the wildlife resources of the United States, and the listing will prevent the purposeful or accidental introduction and subsequent establishment of these 10 fish and 1 crayfish into ecosystems of the United States. We are also making available for public review and comment the associated draft environmental assessment and draft economic analysis for this action.

DATES:

Comments will be considered if received on or before December 29, 2015.

ADDRESSES:

You may submit comments by one of the following methods:

• Federal eRulemaking Portal: http://www.regulations.gov . In the Search box, enter the docket number for the proposed rule, which is FWS-HQ-FAC-2013-0095. Click on “Comment Now!” to submit a comment. Please ensure that you have found the correct rulemaking before submitting your comment.

• U.S. mail or hand delivery: Public Comments Processing, Attn: FWS-HQ-FAC-2013-0095; U.S. Fish and Wildlife Service Headquarters, MS: BPHC, 5275 Leesburg Pike, Falls Church, VA 22041-3803.

Comments will not be accepted by email or faxes. All comments will be posted on http://www.regulations.gov . This generally means that any personal information provided will be posted (see Public Comments, below, for more information).

FOR FURTHER INFORMATION CONTACT:

Susan Jewell, U.S. Fish and Wildlife Service, MS-FAC, 5275 Leesburg Pike, Falls Church, VA 22041-3803; 703-358-2416. If a telecommunications device for the deaf (TDD) is required, please call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

ormation Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

The U.S. Fish and Wildlife Service (Service) proposes to amend its regulations to add to the list of injurious fish the following nonnative freshwater fish species: Crucian carp, Eurasian minnow, Prussian carp, roach, stone moroko, Nile perch, Amur sleeper, European perch, zander, and wels catfish. In addition, the Service proposes to amend its regulations to add the common yabby, a nonnative freshwater crayfish species, to the list of injurious crustaceans. These listings would prohibit the importation of any live animal, gamete, viable egg, or hybrid of these 10 fish and 1 crayfish (11 species) into the United States, except as specifically authorized. These listings would also prohibit the interstate transportation of any live animal, gamete, viable egg, or hybrid of these 10 fish and 1 crayfish, except as specifically authorized. If the proposed rule is made final, importation and interstate transportation of any live animal, gamete, viable egg, or hybrid of these 10 fish and 1 crayfish could be authorized only by permit for scientific, medical, educational, or zoological purposes, or without a permit by Federal agencies solely for their own use. This action is necessary to protect human beings and the interests of agriculture, wildlife, or wildlife resources from the purposeful or accidental introduction and subsequent establishment of these 11 species into ecosystems of the United States.

The need for the proposed action to add 11 nonnative species to the list of injurious wildlife under the Lacey Act developed from the Service's concern that, through our rapid screen process, these 11 species were categorized as “high risk” for invasiveness. All 11 species have a high climate match in parts of the United States, a history of invasiveness outside their native ranges, and, except for one fish species in one lake, are not currently found in U.S. ecosystems

f injurious wildlife under the Lacey Act developed from the Service's concern that, through our rapid screen process, these 11 species were categorized as “high risk” for invasiveness. All 11 species have a high climate match in parts of the United States, a history of invasiveness outside their native ranges, and, except for one fish species in one lake, are not currently found in U.S. ecosystems. Nine of the freshwater fish species (Amur sleeper, crucian carp, Eurasian minnow, European perch, Prussian carp, roach, stone moroko, wels catfish, and zander) have been introduced to and established populations within Europe and Asia, where they have spread and are causing harm. The Nile perch has been introduced to and become invasive in central Africa. The freshwater crayfish, the common yabby, has been introduced to western Australia and to Europe where it has established invasive populations. Most of these species were originally introduced for aquaculture, recreational fishing, or ornamental purposes. Two of these fish species (the Eurasian minnow and stone moroko) were accidently introduced when they were unintentionally transported in shipments with desirable fish species stocked for aquaculture or fisheries management.

A species does not have to be currently imported or present in the United States for the Service to list it as injurious. The objective of this listing is to utilize the Lacey Act's major strength by prohibiting importation and interstate transportation and thus preventing the species' likely introduction and establishment in the wild and likely injuriousness to human beings, the interests of agriculture, or to wildlife or wildlife resources. Based on our evaluation of the injurious nature of all 11 species, the Service seeks to prevent these introductions and establishment within the United States, consistent with the Lacey Act.

We evaluated the 10 fish and 1 crayfish species using the Service's Injurious Wildlife Evaluation Criteria

y injuriousness to human beings, the interests of agriculture, or to wildlife or wildlife resources. Based on our evaluation of the injurious nature of all 11 species, the Service seeks to prevent these introductions and establishment within the United States, consistent with the Lacey Act.

We evaluated the 10 fish and 1 crayfish species using the Service's Injurious Wildlife Evaluation Criteria. The criteria include the likelihood and magnitude of release or escape, of survival and establishment upon release or escape, and of spread from origin of release or escape. The criteria also examine the effect on wildlife resources and ecosystems (such as through hybridizing, competition for food or habitat, predation on native species, and pathogen transfer), on endangered and threatened species and their respective habitats, and on human beings, forestry, horticulture, and agriculture. Additionally, criteria evaluate the likelihood and magnitude of wildlife or

Each of these 11 species has a well-documented history of invasiveness outside of its native range, but not in the United States. When released into the environment, these species have survived and established, expanded their nonnative range, preyed on native wildlife species, and competed with native species for food and habitat. Since it would be difficult to eradicate, manage, or control the spread of these 11 species; it would be difficult to rehabilitate or recover habitats disturbed by these species; and because introduction of these 11 species would negatively affect agriculture, human beings, and native wildlife or wildlife resources, the Service is proposing to amend its regulations to add these 11 species as injurious under the Lacey Act. This listing would prohibit the importation and interstate transportation of any live animal, gamete, viable egg, or hybrid in the United States, except as specifically authorized.

This proposed rule is not significant under Executive Order (E.O.) 12866. E.O

wildlife or wildlife resources, the Service is proposing to amend its regulations to add these 11 species as injurious under the Lacey Act. This listing would prohibit the importation and interstate transportation of any live animal, gamete, viable egg, or hybrid in the United States, except as specifically authorized.

This proposed rule is not significant under Executive Order (E.O.) 12866. E.O. 12866 Regulatory Planning and Review (Panetta 1993) and the subsequent document, Economic Analysis of Federal Regulations under E.O. 12866 (U.S. Office of Management and Budget 1996) require the Service to ensure that proper consideration is given to the effect of this proposed action on the business community and economy. With respect to the regulations under consideration, analysis that comports with the Circular A-4 would include a full description and estimation of the economic benefits and cost associated with the implementation of the regulations. The economic effects to three groups would be addressed: (1) Producers; (2) consumers; and (3) society. Of the 11 species, only one population of one species (zander) is found in the wild in the United States. Of the 11 species, 1 species (yabby) is in the aquarium trade in the United States; 3 species (crucian carp, Nile perch, and wels catfish) have been imported in small numbers since 2011; and 7 species are not in U.S. trade. Therefore, the economic effect in the United States is negligible or nil. The draft economic analysis that the Service prepared supports this conclusion (USFWS Draft Economic Analysis 2015).

Background

The regulations contained in 50 CFR part 16 implement the Lacey Act (the Act; 18 U.S.C. 42, as amended)

fish) have been imported in small numbers since 2011; and 7 species are not in U.S. trade. Therefore, the economic effect in the United States is negligible or nil. The draft economic analysis that the Service prepared supports this conclusion (USFWS Draft Economic Analysis 2015).

Background

The regulations contained in 50 CFR part 16 implement the Lacey Act (the Act; 18 U.S.C. 42, as amended). Under the terms of the Act, the Secretary of the Interior is authorized to prescribe by regulation those wild mammals, wild birds, fish, mollusks, crustaceans, amphibians, reptiles, and the offspring or eggs of any of the foregoing that are injurious to human beings, to the interests of agriculture, horticulture, forestry, or to wildlife or the wildlife resources of the United States. The lists of injurious wildlife species are found in title 50 of the Code of Federal Regulations (CFR) at §§ 16.11 through 16.15.

The purpose of listing the crucian carp, Eurasian minnow, Prussian carp, roach, stone moroko, Nile perch, Amur sleeper, European perch, zander, and wels catfish and the common yabby (hereafter “11 species”) as injurious wildlife is to prevent the harm that these species could cause to the interests of agriculture, human beings, wildlife, and wildlife resources through their accidental or intentional introduction and establishment into the wild in the United States.

The Service evaluated each of the 11 species individually and determined them to be injurious. Therefore, for these 11 species, their importation into, or transportation between, the States, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States of live animals, gametes, viable eggs, or hybrids, except by permit for zoological, educational, medical, or scientific purposes (in accordance with permit regulations 50 CFR 16.22), or by Federal agencies without a permit solely for their own use, upon filing a written declaration with the District Director of Customs and the U.S

of Puerto Rico, or any territory or possession of the United States of live animals, gametes, viable eggs, or hybrids, except by permit for zoological, educational, medical, or scientific purposes (in accordance with permit regulations 50 CFR 16.22), or by Federal agencies without a permit solely for their own use, upon filing a written declaration with the District Director of Customs and the U.S. Fish and Wildlife Service Inspector at the port of entry. The rule would not prohibit intrastate transport of the listed fish or crayfish species. Any regulations pertaining to the transport or use of these species within a particular State would continue to be the responsibility of that State.

How the 11 Species Were Selected for Consideration as Injurious Species

While the Service recognizes that not all nonnative species become invasive, it is important to have some understanding of the risk that nonnative species pose to the United States. Therefore, the Service utilizes a rapid screening process to provide a prediction of the invasive potential of nonnative species. Rapid screens categorize risk as either high, low, or uncertain and have been produced for hundreds of foreign aquatic fish and invertebrates for use by the Service and other entities. Each rapid screen is summarized in an Ecological Risk Screening Summary (ERSS; see “Rapid Screening” for explanation regarding how these summaries were done). The Service selected 11 species with a rapid screen result of “high risk” to consider for listing as injurious. These 11 species have a high climate match (see Rapid Screening) in parts of the United States, a history of invasiveness outside of their native range (see Need for the Proposed Rule ), are not yet found in U.S. ecosystems (except for one), and have a high degree of certainty regarding these results. Other species meet these criteria and will be considered in subsequent rules

xed with and introduced with shipments of fish stocked for other intended purposes. Consistent with 18 U.S.C. 42, the Service aims to prevent the introduction and establishment of all 11 species within the United States due to concerns regarding the potential injurious effects of the 11 species on human beings, the interests of agriculture, or to wildlife or wildlife resources of the United States.

Need for the Proposed Rule

The threat posed by these 11 species is evident in their history of invasiveness in other countries and have a high risk of establishment as demonstrated by a high climate match within the United States. Invasive species means “an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health” (Executive Order 13112 on Invasive Species, 1999). A history of invasiveness means that a species has been introduced (either intentionally or unintentionally) to an area or areas where it is not native and has subsequently been scientifically documented to have caused harm to the environment.

Based on the results of rapid screening assessments and our injurious wildlife evaluation, we anticipate that these 11 species would become invasive if they are introduced and become established in waters of the United States. All of these species have wide distribution ranges (where they are native and where they are invasive), suggesting they are highly adaptable and tolerant of new environments and opportunistic when expanding from their native range. Under the Act, the Service has the ability to prevent the introduction of injurious wildlife that poses a threat to the United States. Preventing injurious wildlife from entering the United States is widely considered the most economically effective and efficient management approach for avoiding the adverse ecological effects and economic costs often caused by invasive species.

their native range. Under the Act, the Service has the ability to prevent the introduction of injurious wildlife that poses a threat to the United States. Preventing injurious wildlife from entering the United States is widely considered the most economically effective and efficient management approach for avoiding the adverse ecological effects and economic costs often caused by invasive species..

Listing Process

The Service promulgates regulations under the Act in accordance with the Administrative Procedure Act (APA; 5 U.S.C. 551 et seq. ). We are publishing a proposed rule for public notice and comment. We also solicit peer review under Office of Management and Budget (OMB) guidelines “Final Information Quality Bulletin for Peer Review” (OMB 2004). We also make available to the public an economic analysis (including analysis of potential effects on small businesses) if appropriate. We also follow National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq. ) requirements, which may include preparing an environmental assessment or environmental impact statement, also available to the public. For this proposed rule, we prepared a draft economic analysis and a draft environmental assessment.

This proposed rule is based on an evaluation using the Service's Injurious Wildlife Evaluation Criteria (see Injurious Wildlife Evaluation Criteria, below, for more information). We use these criteria to evaluate whether a species does or does not qualify as injurious under the Act. These criteria include the likelihood and magnitude of release or escape, of survival and establishment upon release or escape, and of spread from origin of release or escape. These criteria also examine the impact on wildlife resources and ecosystems (such as through hybridizing, competition for food or habitat, predation on native species, and pathogen transfer), on endangered and threatened species and their respective habitats, and on human beings, forestry, horticulture, and agriculture

ishment upon release or escape, and of spread from origin of release or escape. These criteria also examine the impact on wildlife resources and ecosystems (such as through hybridizing, competition for food or habitat, predation on native species, and pathogen transfer), on endangered and threatened species and their respective habitats, and on human beings, forestry, horticulture, and agriculture. Additionally, criteria evaluate the likelihood and magnitude of wildlife or habitat damages resulting from measures to control the proposed species. The analysis using these criteria serves as a basis for the Service's regulatory decision regarding injurious wildlife species listings. The objective of such a listing would be to prohibit importation and interstate transportation and thus prevent the species' likely introduction and establishment in the wild, thereby preventing injurious effects consistent with 18 U.S.C. 42.

We are evaluating each of the 11 species individually and will list only those species that we determine to be injurious. If a determination is made to not finalize a listing, the Service will publish notice in the Federal Register announcing that it is withdrawing the proposed rule with respect to any such species. If a determination is made to finalize the listing of a species as injurious after evaluating the comments we receive during this proposed rule's comment period, a final rule would be published. The final rule would contain responses to comments we receive on the proposed rule, state the final decision, and provide the justification for that decision. If listed, species determined to be injurious will be identified in the Code of Federal Regulations.

Introduction Pathways for the 11 Species

to be injurious will be identified in the Code of Federal Regulations.

Introduction Pathways for the 11 Species

The primary potential pathways for the 11 species into the United States are through commercial trade in the live animal industry, including aquaculture, recreational fishing, bait, and ornamental display. Some could arrive unintentionally in water used to carry other aquatic species. Aquatic species may be imported into many designated ports of entry, including Miami, Los Angeles, Baltimore, Dallas-Fort Worth, Detroit, Chicago, and San Francisco. Once imported, these species may be transported throughout the country for aquaculture, recreational and commercial fishing, aquaculture, bait, display, and other possible uses.

Aquaculture is the farming of aquatic organisms, such as fish, crustaceans, mollusks, and plants for food, pets, stocking for fishing, and other purposes. Aquaculture usually occurs in a controlled setting where the water is contained, as a pond or in a tank, and is separate from lakes, ponds, rivers, and other natural waters. The controlled setting allows the aquaculturist to maintain proper conditions for each species being raised, which promotes optimal feeding and provides protection from predation and disease. However, Bartley (2011) states that aquaculture is the primary reason for the deliberate movement of aquatic species outside of their range, and Casal (2006) states that many countries are turning to aquaculture for human consumption, and that has led to the introduction and establishment of these species in local ecosystems. Although the farmed species are normally safely contained, outdoor aquaculture ponds have often flooded from major rainfall events and merged with neighboring natural waters, allowing the farmed species to escape by swimming or floating to nearby watersheds

are turning to aquaculture for human consumption, and that has led to the introduction and establishment of these species in local ecosystems. Although the farmed species are normally safely contained, outdoor aquaculture ponds have often flooded from major rainfall events and merged with neighboring natural waters, allowing the farmed species to escape by swimming or floating to nearby watersheds. Once a species enters a watershed, it has the potential to establish and spread throughout the watershed, which then increases the risk of spread to neighboring watersheds through further flooding. Other pathways for aquaculture species to enter natural waters include intentional stocking programs, and through unintentional stocking when the species is inadvertently included in a shipment with an intended species for stocking (Bartley 2011), release of unwanted ornamental fish, and release of live bait by fishermen.

Stocking for recreational fishing is a common pathway for invasive species when an aquatic species is released into a water body where it is not native. Often it takes repeated releases before the fish (or other animal) becomes established. The type of species that are typically selected and released for recreational fishing are predatory, grow quickly and to large sizes, reproduce abundantly, and are adaptable to many habitat conditions (Fuller et al. 1999). These are often the traits that also contribute to the species becoming invasive (Copp et al. 2005c; Kolar and Lodge 2001, 2002). Live aquatic species, such as fish and crayfish, are frequently used as bait for recreational and commercial fishing. Generally, bait et al. (2012) reported that 65 and 69 percent of Maryland anglers using fishes and crayfishes, respectively, released their unused bait, and that a nonnative, potentially invasive species imported into the State as bait is likely to be released into the wild. Often, these individuals survive, establish, and cause harm to that waterbody (Fuller et al. 1999; Kilian et al. 2012)

hing. Generally, bait et al. (2012) reported that 65 and 69 percent of Maryland anglers using fishes and crayfishes, respectively, released their unused bait, and that a nonnative, potentially invasive species imported into the State as bait is likely to be released into the wild. Often, these individuals survive, establish, and cause harm to that waterbody (Fuller et al. 1999; Kilian et al. 2012). Litvak and Mandrak (1993) found that 41 percent of anglers released live bait after use. Their survey found nearly all the anglers who released their bait thought they were doing a good thing for the environment. When the authors examined the purchase location and the angling destination, they concluded that 18 of the 28 species found in the dealers' bait tanks may have been used outside their native range. Therefore, it is not surprising that so many species are introduced in this manner; Ontario, Canada alone has more than 65 legal baitfish species, many of which are not native to some or all of Ontario (Cudmore and Mandrak 2005). Ludwig and Leitch (1996) concluded that the probability of at least 1,000 bait release events from the Mississippi Basin to the Hudson Bay Basin in one year is close to 1 (a certainty).

Ornamental aquatic species are species kept in aquaria and aquatic gardens for display for entertainment or public education. The most sought-after species frequently are not native to the display area. Ornamental species may accidentally escape from outdoor ponds into neighboring waterbodies (Andrews 1990; Fuller et al. 1999; Gherardi 2011b). They may also be released outdoors intentionally when owners no longer wish to maintain them, despite laws in most States prohibiting release into the wild. The first tropical freshwater fish became available in trade in the United States in the early 1900s (Duggan 2011), and there is currently a large variety of freshwater and saltwater fish in the ornamental trade. The trade in ornamental crayfish species is more recent but is growing rapidly (Gherardi 2011b)

onger wish to maintain them, despite laws in most States prohibiting release into the wild. The first tropical freshwater fish became available in trade in the United States in the early 1900s (Duggan 2011), and there is currently a large variety of freshwater and saltwater fish in the ornamental trade. The trade in ornamental crayfish species is more recent but is growing rapidly (Gherardi 2011b).

The invasive range of many of the species in this proposed rule has expanded through intentional release for commercial and recreational fishing (European perch, Nile perch, Prussian carp, roach, wels catfish, zander, and common yabby), as bait (Eurasian minnow, roach, common yabby), and as ornamental fish (Amur sleeper, stone moroko), and unintentionally (Amur sleeper, crucian carp, Eurasian minnow, and stone moroko) with shipments of other aquatic species. All 11 species have proven that they are capable of naturally dispersing through waterways.

More importantly, the main factors influencing the chances of these 11 species establishing in the wild would be the propagule pressure, defined as the frequency of release events (propagule number) and numbers of individuals released (propagule size) (Williamson 1996; Colautti and MacIsaac 2004; Duncan 2011). This increases the odds of both genders being released and finding mates and of those individuals being healthy and vigorous. After a sufficient number of unintentional or intentional releases, a species may establish in those regions suitable for its survival and reproduction. Thus, allowing the importation and unregulated interstate transport of these 11 species subsequently increases the risk of any of these species becoming established within the United States.

An additional factor contributing to an invasive species' successful establishment is a documented history of these same species successfully establishing elsewhere outside of their native ranges

production. Thus, allowing the importation and unregulated interstate transport of these 11 species subsequently increases the risk of any of these species becoming established within the United States.

An additional factor contributing to an invasive species' successful establishment is a documented history of these same species successfully establishing elsewhere outside of their native ranges. All 11 species have been introduced, become established, and been documented as causing harm in countries outside of their native ranges. For example, the stone moroko's native range includes southern and central Japan, Taiwan, Korea, China, and the Amur River basin (Copp et al. 2010). Since the stone moroko's original introduction to Romania in the early 1960s, this species has invaded nearly every European country and additional regions of Asia (Welcomme 1988; Copp et al. 2010; Froese and Pauly 2014). Thus, a high climate and habitat match between the species' native range and its introduced range has contributed significantly to its successful establishment.

As mentioned above, a species does not have to be currently imported or present in the United States for the Service to list it as injurious. The objective of this listing is to utilize the Act's major strength to prohibit importation and interstate transportation and thus prevent the species' likely introduction and establishment in the wild and likely harm to human beings, the interests of agriculture, or wildlife or wildlife resources, thereby preventing injurious effects consistent with the Lacey Act.

Public Comments

The Service is soliciting substantive public comments and supporting data on the draft environmental assessment, the draft economic analysis, and this proposed rule to add the 11 species to the list of injurious wildlife under the Act. This proposed rule and supporting materials will be available on http://www.regulations.gov under Docket No. FWS-HQ-FAC-2013-0095

the Lacey Act.

Public Comments

Comments and materials concerning this rule may be submitted by one of the methods listed in ADDRESSES . Comments sent by email or fax or to an address not listed in ADDRESSES will not be accepted.

We will post your entire comment—including your personal identifying information—on http://www.regulations.gov . If your written comments provide personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that this information will not be published.

Those comments and materials that we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public review at http://www.regulations.gov under Docket No. FWS-HQ-FAC-2013-0095, or by appointment, during normal business hours at U.S. Fish and Wildlife Service Headquarters (see FOR FURTHER INFORMATION CONTACT ).

We are soliciting public comments and supporting data to gain additional information, and we specifically seek comment regarding the crucian carp, Eurasian minnow, Prussian carp, roach, stone moroko, Nile perch, Amur sleeper, European perch, zander, and wels catfish and the common yabby on the following questions:

(1) What regulations does your State or Territory have pertaining to the use, possession, sale, transport, or production of any of the 11 species in this proposed rule? What are relevant Federal, State, or local rules that may duplicate, overlap, or conflict with the proposed Federal regulation?

r sleeper, European perch, zander, and wels catfish and the common yabby on the following questions:

(2) Are any of the 11 species currently found in the wild in any of the States or Territories? If so, which species and where?

(3) Are any of the 11 species currently in production for wholesale or retail sale, and in which States?

(4) What would it cost to eradicate individuals or populations of any of the 11 species, or similar species, if found in the United States? What methods are effective?

(5) What State-protected species would be adversely affected by the introduction of any of the 11 species?

(6) What provisions in the proposed rule should the Service consider with

(7) How could the proposed rule be modified to reduce any costs or burdens for small entities consistent with the Service's requirements?

(8) Should we include or not include hybrids of the species analyzed in this proposed rule, and would the hybrids be likely to possess the same biological characteristics as the parent species?

Species Information

We obtained our information on a species' biology, history of invasiveness, and climate matching from a variety of sources, including the U.S. Geological Survey Nonindigenous Aquatic Species (NAS) database, Centre for Agricultural Bioscience International's Invasive Species Compendium (CABI ISC), ERSS reports, and primary literature. We queried the NAS database ( http://nas.er.usgs.gov/ ) to confirm that 10 of the 11 species are not currently established in U.S. ecosystems. The zander is established in a lake in North Dakota (Fuller 2009)

eological Survey Nonindigenous Aquatic Species (NAS) database, Centre for Agricultural Bioscience International's Invasive Species Compendium (CABI ISC), ERSS reports, and primary literature. We queried the NAS database ( http://nas.er.usgs.gov/ ) to confirm that 10 of the 11 species are not currently established in U.S. ecosystems. The zander is established in a lake in North Dakota (Fuller 2009). The CABI ISC ( http://www.cabi.org/isc/ ) is a constantly developing, encyclopedic resource containing datasheets on more than 1,500 invasive species and animal diseases. The Service contracted with CABI for many of the species-specific datasheets that we used in preparation of this proposed rule. The datasheets were prepared by world experts on the species, and each datasheet was reviewed by expert peer reviewers. The datasheets served as sources of compiled information that allowed us to prepare this proposed rule efficiently.

Crucian Carp (Carassius carassius)

The crucian carp was first described and cataloged by Linnaeus in 1758, and is part of the order Cypriniformes and family Cyprinidae. The family Cyprinidae, or the carp and minnow family, is a large and diverse group that includes 2,963 freshwater species (Froese and Pauly 2014).

Native Range and Habitat

The crucian carp inhabits a temperate climate (Riehl and Baensch 1991). The native range includes much of north and central Europe, extending from the North Sea and Baltic Sea basins across northern France and Germany to the Alps and through the Danube River basin and eastward to Siberia (Godard and Copp 2012). The species inhabits freshwater lakes, ponds, rivers, and ditches (Godard and Copp 2012). This species can survive in water with low dissolved oxygen levels, including aquatic environments with greatly reduced oxygen (hypoxic) or largely devoid of dissolved oxygen (anoxic) (Godard and Copp 2012)

Germany to the Alps and through the Danube River basin and eastward to Siberia (Godard and Copp 2012). The species inhabits freshwater lakes, ponds, rivers, and ditches (Godard and Copp 2012). This species can survive in water with low dissolved oxygen levels, including aquatic environments with greatly reduced oxygen (hypoxic) or largely devoid of dissolved oxygen (anoxic) (Godard and Copp 2012).

Nonnative Range and Habitat

Crucian carp have been widely introduced to and established in Croatia, Greece, southern France (Holčík 1991; Godard and Copp 2012), Italy, and England (Kottelat and Freyhof 2007), Spain, Belgium, Israel, Switzerland, Chile, India, Sri Lanka, Philippines (Holčík 1991; Froese and Pauly 2014), and Turkey (Innal and Erk'akan 2006). In the United States, crucian carp may have been established within Chicago (Illinois) lakes and lagoons in the early 1900s (Meek and Hildebrand 1910; Schofield et al. 2005), but apparently died out because currently no such population exists (Welcomme 1988; Schofield et al. 2005; Schofield et al. 2013).

Several other fish species, including the Prussian carp, a brown variety of goldfish ( Carassius auratus ), and the common carp ( Cyprinus carpio ), have been misidentified as crucian carp (Godard and Copp 2012). Crucian carp may have been accidently introduced to some regions in misidentified shipments of ornamental fish (Wheeler 2000; Hickley and Chare 2004). However, no known populations of crucian carp currently exist in the United States.

Biology

Crucian carp generally range from 20 to 45 centimeters (cm) (8 to 18 inches (in)) long with a maximum of 50 cm (19.5 in) (Godard and Copp 2012). Specimens have been reported to weigh up to 3 kilograms (kg) (6.6 pounds (lb)) (Froese and Pauly 2014). These fish have an olive-gray back that transitions into brassy green along the sides and brown on the body (Godard and Copp 2012)

States.

Biology

Crucian carp can live up to 10 years (Kottelat and Freyhof 2007) and reach sexual maturity at one and a half years but may not begin spawning until their third year (Godard and Copp 2012). Crucian carp are batch spawners (release multiple batches of eggs per season) and may spawn one to three times per year (Aho and Holopainen 2000, Godard and Copp 2012).

Crucian carp feed during the day and night on plankton, benthic (bottom-dwelling) invertebrates, plant materials, and detritus (organic material) (Kottelat and Freyhof 2007).

Crucian carp can harbor the fish disease spring viraemia of carp (SVC) (Ahne et al. 2002) and several parasitic infections ( Dactylogyrus gill flukes disease, Trichodinosis, skin flukes, false fungal infection, and turbidity of the skin) (Froese and Pauly 2014). SVC is a disease that, when found, is required to be reported to the Office International des Epizooties (OIE) (World Organisation of Animal Health) (Ahne et al. 2002). The SVC virus infects carp species but may be transmitted to other fish species. The virus is shed with fecal matter and urine, and often infects through waterborne transmission (Ahne et al. 2002). Additionally, SVC may result in significant morbidity and mortality with an approximate 70 percent fatality among juvenile fish and 30 percent fatality in adult fish (Ahne et al. 2002). Thus, the spread of SVC may have serious effects on native fish stocks. OIE-notifiable diseases affect animal health internationally.

OIE-notifiable diseases meet certain criteria for consequences, spread, and diagnosis

nally, SVC may result in significant morbidity and mortality with an approximate 70 percent fatality among juvenile fish and 30 percent fatality in adult fish (Ahne et al. 2002). Thus, the spread of SVC may have serious effects on native fish stocks. OIE-notifiable diseases affect animal health internationally.

OIE-notifiable diseases meet certain criteria for consequences, spread, and diagnosis. For the consequences criteria, the disease must have either been documented as causing significant production losses on a national or multinational (zonal or regional) level, or have scientific evidence that indicates that the diseases will cause significant morbidity or mortality in wild aquatic animal populations, or be an agent of public health concern. For the spread criteria, the disease's infectious etiology (cause) must be known or an infectious agent is strongly associated with the disease (with etiology unknown). In addition for the spread criteria, there must be a likelihood of international spread (via live animals and animal products) and the disease must not be widespread (several countries or regions of countries without specific disease). For the diagnosis criteria, there must be a standardized, proven diagnostic test for disease detection (OIE 2012). These internationally-accepted standards, including those that document the consequences (harm) of certain diseases, offer supporting evidence of injuriousness.

Invasiveness

This species demonstrates many of the strongest traits for invasiveness. The crucian carp is capable of securing and ingesting a wide range of food, has a broad native range, and is highly adaptable to different environments (Godard and Copp 2012). Crucian carp can increase turbidity (cloudiness of water) in lakes, rivers, and streams with soft bottom sediments while scavenging along the substrate

Eurasian Minnow (Phoxinus phoxinus)

The Eurasian minnow was first described and cataloged by Linnaeus in 1758, and belongs to the order Cypriniformes and family Cyprinidae (ITIS 2014). Although Eurasian minnow is the preferred common name, this fish species is also referred to as the European minnow.

Native Range and Habitat

The Eurasian minnow inhabits a temperate climate, and the native range includes much of Eurasia within the basins of the Atlantic, North and Baltic Seas, and the Arctic and the northern Pacific Oceans (Froese and Pauly 2014).

Eurasian minnows can be found in a variety of habitats ranging from brackish (estuarine; slightly salty) to freshwater streams, rivers, ponds, and lakes located within the coastal zone to the mountains (Sandlund 2008). In Norway, they are found at elevations up to 2,000 m (6,562 ft). These minnows prefer shallow lakes or slow-flowing streams and rivers with stony substrate (Sandlund 2008).

Nonnative Range and Habitat

The Eurasian minnow's nonnative range includes parts of Sweden and Norway, United Kingdom, and Egypt (Sandlund 2008), as well as other drainages juxtaposed to native waterways. The Eurasian minnow was initially introduced as live bait, which was the main pathway of introduction throughout the 1900s (Sandlund 2008). The inadvertent inclusion of this minnow species in the transport water of brown trout ( Salmo trutta ) that were intentionally stocked into lakes for recreational angling has contributed to their spread (Sandlund 2008)

rainages juxtaposed to native waterways. The Eurasian minnow was initially introduced as live bait, which was the main pathway of introduction throughout the 1900s (Sandlund 2008). The inadvertent inclusion of this minnow species in the transport water of brown trout ( Salmo trutta ) that were intentionally stocked into lakes for recreational angling has contributed to their spread (Sandlund 2008). From these initial stockings, minnows have swum downstream and established in new waterways, and have spread to new waterways through tunnels constructed for hydropower development. These minnows have also been purposely introduced as food for brown trout and to control the Tune fly (in Simuliidae) (Sandlund 2008).

The Eurasian minnow is expanding its nonnative range by establishing populations in additional waterways bordering the native range. Waterways near where the minnow is already established are most at risk (Sandlund 2008).

Biology

The Eurasian minnow has a torpedo-shaped body measuring 6 to 10 cm (2.3 to 4 in) with a maximum of 15 cm (6 in). Size and growth rate are both highly dependent on population density and environmental factors (Lien 1981; Mills 1987, 1988; Sandlund 2008). These minnows have variable coloration but are often brownish-green on the back with a whitish stomach and brown and black blotches along the side (Sandlund 2008).

The Eurasian minnow's life-history traits (age, size at sexual maturity, growth rate, and life span) may be highly variable (Mills 1988). Populations residing in lower latitudes often have smaller body size and younger age of maturity than those populations in higher altitudes and latitudes (Mills 1988). Maturity ranges from less than 1 year to 6 years of age, with a lifespan as long as 13 to 15 years (Sandlund 2008). The Eurasian minnow spawns annually with an average fecundity between 200 to 1,000 eggs (Sandlund 2008).

This minnow usually cohabitates with salmonid fishes (Kottelat and Freyhof 2007)

d younger age of maturity than those populations in higher altitudes and latitudes (Mills 1988). Maturity ranges from less than 1 year to 6 years of age, with a lifespan as long as 13 to 15 years (Sandlund 2008). The Eurasian minnow spawns annually with an average fecundity between 200 to 1,000 eggs (Sandlund 2008).

This minnow usually cohabitates with salmonid fishes (Kottelat and Freyhof 2007). The Eurasian minnow feeds mostly on invertebrates (crustaceans and insect larvae) as well as some algal and plant material (Lien 1981).

Invasiveness

The Eurasian minnow demonstrates many of the strongest traits for invasiveness. The species is highly adaptable to new environments and is difficult to control (Sandlund 2008). The species can become established within varying freshwater systems, including lowland and high alpine areas, as well as in brackish water (Sandlund 2008). Introductions of the Eurasian minnow can cause major changes to nonnative ecosystems by affecting the benthic community (decreased invertebrate diversity) and disrupting trophic level structure (Sandlund 2008). This affects the ability of native fish to find food as well as disrupts native spawning. The Eurasian minnow has been shown to reduce recruitment of brown trout by predation (Sandlund 2008). Although brown trout are not native to the United States, they are closely related to our native trout and salmon, and thus Eurasian minnows could be expected to reduce the recruitment of native trout.

In addition, Eurasian minnows are carriers of parasites and have increased the introduction of parasites to new areas. Such parasites affected native snails, mussels, and different insects within subalpine lakes in southern Norway following introduction of the Eurasian minnows (Sandlund 2008). Additionally, Zietara et al. (2008) used molecular methods to link the parasite Gyrodactylus aphyae from Eurasian minnows to the new hosts of Atlantic salmon ( Salmo salar ) and brown trout

duction of parasites to new areas. Such parasites affected native snails, mussels, and different insects within subalpine lakes in southern Norway following introduction of the Eurasian minnows (Sandlund 2008). Additionally, Zietara et al. (2008) used molecular methods to link the parasite Gyrodactylus aphyae from Eurasian minnows to the new hosts of Atlantic salmon ( Salmo salar ) and brown trout.

Prussian Carp (Carassius gibelio)

The Prussian carp was first described and catalogued by Bloch in 1782, and belongs to the order Cypriniformes and family Cyprinidae (ITIS 2014).

Native Range and Habitat

The Prussian carp inhabits a temperate climate (Baensch and Riehl 2004). The species is native to regions of central Europe and eastward to Siberia. It is also native to several Asian countries, including China, Georgia, Kyrgyzstan, Mongolia, Turkey, and Turkmenistan (Britton 2011). The Prussian carp resides in a variety of fresh stillwater bodies and rivers. This species also inhabits warm, shallow, eutrophic (high in nutrients) waters with submerged vegetation or regular flooding events (Kottelat and Freyhof 2007). This species can live in polluted waters with pollution and low oxygen concentrations (Britton 2011).

Nonnative Range and Habitat

The Prussian carp has been introduced to many countries within central and Western Europe. This species was first introduced to Belgium during the 1600s and is now prevalent in Belgian freshwater systems. The Prussian carp was also introduced to Belarus and Poland during 1940s for recreational fishing and aquaculture. This carp species has dispersed and expanded its range using the Vistula and Bug River basins (Britton 2011). During the mid to late 1970s, this carp species invaded the Czech Republic river system from the Danube River via the Morava River. Once in the river system, the fish expanded into tributary streams and connected watersheds

and Poland during 1940s for recreational fishing and aquaculture. This carp species has dispersed and expanded its range using the Vistula and Bug River basins (Britton 2011). During the mid to late 1970s, this carp species invaded the Czech Republic river system from the Danube River via the Morava River. Once in the river system, the fish expanded into tributary streams and connected watersheds. Throughout its nonnative range, this species has been stocked with common carp and misidentified as crucian carp (Britton 2011). From the original stocked site, the Prussian carp has dispersed both naturally (swimming) and with human involvement.

The Prussian carp's current nonnative range includes the Asian countries of et al. 2015). The species was recently found to be established in waterways in southern Alberta, Canada (Elgin et al. 2014).

Biology

The Prussian carp has a silvery-brown body with an average length of 20 cm (7.9 in) and reported maximum length of 35 cm (13.8 in) (Kottelat and Freyhof 2007, Froese and Pauly 2014). This species has a reported maximum weight of 3 kilograms (kg; 6.6 pounds (lb) (Froese and Pauly 201b).

The Prussian carp lives up to 10 years (Kottelat and Freyhof 2007). This species can reproduce in a way very rare among fish. Introduced populations often include, or are solely composed of, triploid females that can undergo natural gynogenesis, allowing them to reproduce from unfertilized eggs (Britton 2011). Thus, the eggs are viable without being fertilized by males.

The Prussian carp is a generalist omnivore and consumes a varied diet that includes plankton, benthic invertebrates, plant material, and detritus (Britton 2011).

The parasite Thelohanellus wuhanensis (Wang et al. 2001) and black spot disease (Posthodiplostomatosis) have been found to affect the Prussian carp (Markovíc et al. 2012).

Invasiveness

The Prussian carp is a highly invasive species in freshwater ecosystems throughout Europe and Asia

umes a varied diet that includes plankton, benthic invertebrates, plant material, and detritus (Britton 2011).

The parasite Thelohanellus wuhanensis (Wang et al. 2001) and black spot disease (Posthodiplostomatosis) have been found to affect the Prussian carp (Markovíc et al. 2012).

Invasiveness

The Prussian carp is a highly invasive species in freshwater ecosystems throughout Europe and Asia. This fish species grows rapidly and can reproduce from unfertilized eggs (Vetemaa et al. 2005). Prussian carp have been implicated in the decline in both the biodiversity and population of native fish (Vetemaa et al. 2005, Lusk et al. 2010). The presence of this fish species has been linked with increased water turbidity (Crivelli 1995), which in turn alters both the ecosystem's trophic level structure and nutrient availability.

Roach (Rutilus rutilus)

The roach was first described and cataloged by Linnaeus in 1758, and belongs to the order Cypriniformes and family Cyprinidae (ITIS 2014).

Native Range and Habitat

The roach inhabits temperate climates (Riehl and Baensch 1991). The species' native range includes regions of Europe and Asia. Within Europe, it is found north of the Pyrenees and Alps and eastward to the Ural River and Eya drainages (Caspian Sea basin) and within the Aegean Sea basin and watershed (Kottelat and Freyhof 2007). In Asia, the roach's native range extends from the Sea of Marmara basin and lower Sakarya Province (Turkey) to the Aral Sea basin and Siberia (Kottelat and Freyhof 2007).

This species often resides in nutrient-rich lakes, medium to large rivers, and backwaters. Within rivers, the roach is limited to areas with slow currents.

Nonnative Range and Habitat

um to large rivers, and backwaters. Within rivers, the roach is limited to areas with slow currents.

Nonnative Range and Habitat

This species has been introduced to several countries for recreational fishing. Once introduced, the roach has moved into new water bodies within the same country (Rocabayera and Veiga 2012). In 1889, the roach was brought from England to Ireland for use as bait fish. Some of these fish accidently escaped into Cork Blackwater system. After this initial introduction, this fish species was deliberately stocked in nearby lakes. The roach has continued its expansion throughout Ireland watersheds, and by 2000, had invaded every major river system within Ireland (Rocabayera and Veiga 2012).

This species has been reported as invasive in north and central Italy, where it was introduced for recreational fishing (Rocabayera and Veiga 2012). The roach was also introduced to Madagascar, Morocco, Cyprus, Portugal, the Azores, Spain, and Australia (Rocabayera and Veiga 2012).

Biology

The roach has an average body length of 25 cm (9.8 in) and reported maximum length of 50 cm (19.7 in) (Rocabayera and Veiga 2012). The maximum published weight is 1.84 kg (4 lb) (Froese and Pauly 2014).

The roach can live up to 14 years (Froese and Pauly 2013). Male fish are sexually mature at 2 to 3 years and female fish at 3 to 4 years. A whole roach population typically spawns within 5 to 10 days, with each female producing 700 to 77,000 eggs (Rocabayera and Veiga 2012). Eggs hatch approximately 12 days later (Kottelat and Freyhoff 2007).

The roach has a general, omnivorous diet, including benthic invertebrates, zooplankton, plants, and detritus (Rocabayera and Veiga 2012). Of the European cyprinids (carps, minnows, and their relatives), the roach is one of the most efficient molluscivores (Winfield and Winfield 1994)

to 77,000 eggs (Rocabayera and Veiga 2012). Eggs hatch approximately 12 days later (Kottelat and Freyhoff 2007).

Parasitic infections, including worm cataracts ( Diplostomum spathaceum ), black spot disease (diplostomiasis), and tapeworm ( Ligula intestinalis ), have all been found associated with the roach (Rocabayera and Veiga 2012), as has the pathogen bacterium Aeromonas salmonicida, which causes furunculosis (skin ulcers) in several fish species (Wiklund and Dalsgaard 1998).

Invasiveness

The main issues associated with invasive roach populations include competition with native fish species, hybridization with native fish species, and altered ecosystem nutrient cycling (Rocabayera and Veiga 2012). The roach is a highly adaptive species and adapts to a different habitat or diet to avoid predation or competition (Winfield and Winfield 1994).

The roach also has a high reproductive rate and spawns earlier than some other native fish (Volta and Jepsen 2008, Rocabayera and Veiga 2012). This allows larvae to have a competitive edge over native fish larvae (Volta and Jepsen 2008).

The roach can hybridize with other cyprinids, including rudd ( Scardinius erythrophthalmus ) and bream ( Abramis brama ), in places where it has invaded. The new species (roach-rudd cross and roach-bream cross) then compete for food and habitat resources with both the native fish (rudd, bream) and invasive fish (roach) (Rocabayera and Veiga 2012).

Within nutrient-rich lakes or ponds, large populations of roach create adverse nutrient cycling. High numbers of roach consume large amounts of zooplankton, which results in algal blooms, increased turbidity, and changes in nutrient availability and cycling (Rocabayera and Veiga 2012)

habitat resources with both the native fish (rudd, bream) and invasive fish (roach) (Rocabayera and Veiga 2012).

Stone Moroko (Pseudorasbora parva)

The stone moroko was first described and cataloged by Temminick and Schlegel in 1846 and belongs to the order Cypriniformes and family Cyprinidae (ITIS 2014). Although the preferred common name is the stone moroko, this fish species is also called the topmouth gudgeon (Froese and Pauly 2014).

Native Range and Habitat

The stone moroko inhabits a temperate climate (Baensch and Riehl 1993). Its native range is Asia, including southern and central Japan, Taiwan, Korea, China, and the Amur River basin. The stone moroko resides in freshwater lakes, ponds, rivers, streams, and irrigation canals (Copp 2007).

Nonnative Range and Habitat

The stone moroko was introduced to Romania in the early 1960s with a et al. 2010). By 2000, this fish species had invaded nearly every other European country and additional countries in Asia (Copp 2007). This species was primarily introduced unintentionally with fish shipped purposefully. Secondary natural dispersal also occurred in most countries (Copp 2007).

Within Asia, the stone moroko has been introduced to Afghanistan, Armenia, Iran, Kazakhstan, Laos, Taiwan, Turkey, and Uzbekistan (Copp 2007). In Europe, this fish species' nonnative range includes Albania, Austria, Belgium, Bulgaria, Czech Republic, Denmark, France, Germany, Greece, Hungary, Italy, Lithuania, Moldova, Montenegro, Netherlands, Poland, Romania, Russia, Serbia, Slovakia, Spain, Sweden, Switzerland, Ukraine, and the United Kingdom (Copp 2007). The stone moroko has also been introduced to Algeria and Fiji (Copp 2007)

2007). In Europe, this fish species' nonnative range includes Albania, Austria, Belgium, Bulgaria, Czech Republic, Denmark, France, Germany, Greece, Hungary, Italy, Lithuania, Moldova, Montenegro, Netherlands, Poland, Romania, Russia, Serbia, Slovakia, Spain, Sweden, Switzerland, Ukraine, and the United Kingdom (Copp 2007). The stone moroko has also been introduced to Algeria and Fiji (Copp 2007).

Biology

The stone moroko is a small fish with an average body length of 8 cm (3.1 in), maximum reported length of 11 cm (4.3 in) (Froese and Pauly 2014g), and average body mass of 17 to 19 grams (g; 0.04 lb) (Witkowski 2011). This fish species is grayish black with a lighter belly and sides. Juveniles have a dark stripe along the side that disappears with maturity (Witkowski 2011).

This fish species can live up to 5 years (Froese and Pauly 2014). The stone moroko becomes sexually mature and begins spawning at 1 year (Witkowski 2011). Females release several dozen eggs per spawning event and spawn several times per year. The total number of eggs spawned per female ranges from a few hundred to a few thousand eggs (Witkowski 2011). Male fish aggressively guard eggs until hatching (Witkowski 2011).

The stone moroko maintains an omnivorous diet of small insects, fish, mollusks, planktonic crustaceans, fish eggs, algae (Froese and Pauly 2014g), and plants (Kottelat and Freyhof 2007).

The stone moroko is an unaffected carrier of the pathogenic parasite Sphaerothecum destruens (Gozlan et al. 2005, Pinder et al. 2005). This parasite is transferred to water from healthy stone morokos. Once in the water, this parasite has infected Chinook salmon ( Oncorhynchus tshawytscha ), Atlantic salmon, sunbleak ( Leucaspius delineatus ), and fathead minnows ( Pimephales promelas ) (Gozlan et al. 2005). Sphaerothecum destruens infects the internal organs, resulting in spawning failure, organ failure, and death (Gozlan et al. 2005)

parasite is transferred to water from healthy stone morokos. Once in the water, this parasite has infected Chinook salmon ( Oncorhynchus tshawytscha ), Atlantic salmon, sunbleak ( Leucaspius delineatus ), and fathead minnows ( Pimephales promelas ) (Gozlan et al. 2005). Sphaerothecum destruens infects the internal organs, resulting in spawning failure, organ failure, and death (Gozlan et al. 2005).

Invasiveness

The stone moroko has proven to be a highly invasive fish, establishing invasive populations in nearly every European country over a 40-year span (Copp 2007, Copp et al. 2010). This fish species has proven to be adaptive and tolerant of a variety of habitats, including those of poorer quality (Beyer et al. 2007). This species' invasiveness is further aided by multiple spawning events and the guarding of eggs by the male until hatching (Kottelat and Freyhof 2007).

In many areas of introduction and establishment (for example, United Kingdom, Italy, China, and Russia), the stone moroko has been linked to the decline of native freshwater fish populations (Copp 2007). The stone moroko has been found to dominate the fish community when it becomes established. Native fishes have exhibited decreased growth rate and reproduction, and they shifted their diet as a result of food competition (Britton et al. 2010b).

Additionally, this species is a vector of Sphaerothecum destruens, which is a documented pathogen of native salmonids (Gozlan et al. 2005, Gozlan et al. 2009, Andreou et al. 2011). Sphaerothecum destruens has caused mortalities in cultured North American salmon (Andreou et al. 2011)

Nile Perch (Lates niloticus)

The Nile perch was first described and cataloged by Linnaeus in 1758 and is in the order Perciformes and family Centropomidae (ITIS 2014). Although its preferred common name is the Nile perch, it is also referred to as the African snook and Victoria perch (Witte 2013)

erothecum destruens has caused mortalities in cultured North American salmon (Andreou et al. 2011)

Nile Perch (Lates niloticus)

Native Range and Habitat

The Nile perch inhabits a tropical climate with an optimal water temperature of 28 °C (82 °F) and an upper lethal temperature of 38 °C (100 °F) (Kitchell et al. 1997). The species' native distribution includes much of central, western, and eastern Africa. The species is common in the Nile, Chad, Senegal, Volta, and Zaire River basins and brackish Lake Mariout near Alexandria, Egypt (Witte 2013). Nile perch reside in brackish lakes and freshwater lakes, rivers, stream, reservoirs, and irrigation channels (Witte 2013).

Nonnative Range and Habitat

The Nile perch, which is not native to Lake Victoria in Africa, was first introduced to the lake in 1954 from nearby Lake Albert. This species was introduced on the Ugandan side and spread to the Kenyan side. A breeding population existed in the lake by 1962 (Witte 2013). Additional introductions of Nile perch occurred in 1962 and 1963, in Kenyan and Ugandan waters to promote a commercial fishery. The increase in Nile perch population was first noted in Kenyan waters in 1979, in Ugandan waters 2 to 3 years later, and in Tanzanian waters 4 to 5 years later (Witte 2013).

The Nile perch was also introduced to Lake Kyoga (1954 and 1955) to gauge the effects of Nile perch on fish populations similar to that of Lake Victoria. At the time of introduction, people were unaware that this species had already been introduced to Lake Victoria (Witte 2013). Since its initial introduction to Lakes Victoria and Kyoga, this fish species has been accidently and deliberately introduced to many of the neighboring lakes and waterways (Witte 2013)

to gauge the effects of Nile perch on fish populations similar to that of Lake Victoria. At the time of introduction, people were unaware that this species had already been introduced to Lake Victoria (Witte 2013). Since its initial introduction to Lakes Victoria and Kyoga, this fish species has been accidently and deliberately introduced to many of the neighboring lakes and waterways (Witte 2013). There are currently only a few lakes in the area without a Nile perch population (Witte 2013).

The Nile perch was also introduced into Cuba for aquaculture and sport in 1982 and 1983 (Welcomme 1988), but we have no information on the subsequent status.

Nile perch were stocked in Texas waters in 1978, 1979, and 1984 (88, 14, and 26 fish respectively in Victor Braunig Lake); in 1981 (68,119 in Coleto Creek Reservoir); and in 1983 (1,310 in Fairfield Lake) (Fuller et al. 1999, Texas Parks and Wildlife Department 2013a). These introductions were unsuccessful at establishing a self-sustaining population (Howells 1992, Howells 2001). The fish were unable to survive in the cold water temperatures (Howells 2001). Today, Nile perch are a prohibited exotic species in Texas (Texas Parks and Wildlife Department 2013b).

Biology

The Nile perch has a perch-like body with average body length of 100 cm (3.3 ft), maximum length of 200 cm (6.6 ft) (Ribbink 1987, Froese and Pauly 2013), and maximum weight of 200 kg (441 lb) (Ribbink 1987). The Nile perch is gray-blue on the dorsal side with gray-silver along the flank and ventral side (Witte 2013).

The age of sexual maturity varies with habitat location. Most male fish become sexually mature before females (1 to 2 years versus 1 to 4 years of age) (Witte 2013). This species spawns throughout the year with increased spawning during the rainy season (Witte 2013). The Nile perch produce 3 million to 15 million eggs per breeding cycle (Asila and Ogari 1988). This high fecundity

Nile perch less than 5 cm eat zooplankton (cladocerans and copepods) (Witte 2013)

fish become sexually mature before females (1 to 2 years versus 1 to 4 years of age) (Witte 2013). This species spawns throughout the year with increased spawning during the rainy season (Witte 2013). The Nile perch produce 3 million to 15 million eggs per breeding cycle (Asila and Ogari 1988). This high fecundity

Nile perch less than 5 cm eat zooplankton (cladocerans and copepods) (Witte 2013). Juvenile Nile perch (35 to 75 cm long) feed on invertebrates, primarily aquatic insects, crustaceans, and mollusks (Ribbink 1987). Adult Nile perch are piscivorous (fish eaters), they also consume large crustaceans ( Caridina and Macrobrachium shrimp) and insects (Witte 2013).

The Nile perch is host to a number of parasites capable of causing infections and diseases in other species, including sporozoa infections ( Hennegya sp.), Dolops infestation, Ergasilus disease, gonad nematodosis disease ( Philometra sp.), and Macrogyrodactylus and Diplectanum infestation (Paperna 1996, Froese and Pauly 2014f).

Invasiveness

The Nile perch has been listed as one of the 100 “World's Worst” Invaders by the Global Invasive Species Database ( http://www.issg.org ) (Snoeks 2010, ISSG 2015). During the 1950s and 1960s, this fish was introduced to several East African lakes for commercial fishing. This fish is now prevalent in Lake Victoria and contributes to over 90 percent of demersal (bottom-dwelling) fish mass within this lake (Witte 2013). Since its introduction, native fish populations have declined or disappeared (Witte 2013). Approximately 200 native haplochromine cichlid species have become locally extinct due to predation and competition (Snoeks 2010, Witte 2013). Consequently, this has resulted in significant shifts to the trophic level structure and loss of biodiversity of this lake's ecosystem.

Amur Sleeper (Perccottus glenii)

The Amur sleeper was first described and cataloged by B.I. Dybowski in 1877, as part of the order Perciformes and family Odontobutidae (Bogutskaya and Naseka 2002, ITIS 2014)

predation and competition (Snoeks 2010, Witte 2013). Consequently, this has resulted in significant shifts to the trophic level structure and loss of biodiversity of this lake's ecosystem.

Amur Sleeper (Perccottus glenii)

The Amur sleeper was first described and cataloged by B.I. Dybowski in 1877, as part of the order Perciformes and family Odontobutidae (Bogutskaya and Naseka 2002, ITIS 2014). The Amur sleeper is the preferred common name of this freshwater fish, but this fish is also called the Chinese sleeper or rotan (Bogutskaya and Naseka 2002, Froese and Pauly 2014). In this proposed rule, we will refer to the species as the Amur sleeper.

Native Range and Habitat

The Amur sleeper inhabits a temperate climate (Baensch and Riehl 2004). The species' native distribution includes much of the freshwater regions of northeastern China and northern North Korea, the Far East of Russia (Reshetnikov 2004), and South Korea (Grabowska 2011). Within China, this species is predominately native to the lower to middle region of the Amur River watershed, including the Zeya, Sunguri, and Ussuri tributaries (Bogutskaya and Naseka 2002, Grabowska 2011) and Lake Khanka (Courtenay 2006). The Amur sleeper's range extends northward to the Tugur River (Siberia) (Grabowska 2011) and southward to the Sea of Japan (Bogutskaya and Naseka 2002, Grabowska 2011). To the west, the species does not occur in the Amur River upstream of Dzhalinda (Bogutskaya and Nasaka 2002).

The Amur sleeper inhabits freshwater lakes, ponds, canals, backwaters, flood plains, oxbow lakes, and marshes (Grabowska 2011). This fish is a poor swimmer, thriving in slow-moving waters with dense vegetation and muddy substrate and avoiding main river currents (Grabowska 2011). The Amur sleeper can live in poorly oxygenated water and can also survive in dried out or frozen water bodies by burrowing into and hibernating in the mud (Bogutskaya and Nasaka 2002, Grabowska 2011)

ins, oxbow lakes, and marshes (Grabowska 2011). This fish is a poor swimmer, thriving in slow-moving waters with dense vegetation and muddy substrate and avoiding main river currents (Grabowska 2011). The Amur sleeper can live in poorly oxygenated water and can also survive in dried out or frozen water bodies by burrowing into and hibernating in the mud (Bogutskaya and Nasaka 2002, Grabowska 2011).

Although the Amur sleeper is a freshwater fish, there are limited reports of it appearing in saltwater environments (Bogutskaya and Naseka 2002). These reports seem to occur with flood events and are likely a consequence of these fish being carried downstream into these saltwater environments (Bogutskaya and Naseka 2002).

Nonnative Range and Habitat

This species' first known introduction was in western Russia. In 1912, Russian naturalist I.L. Zalivskii brought four Amur sleepers to the Lisiy Nos settlement (St. Petersburg, Russia) (Reshetnikov 2004, Grabowska 2011). These four fish were held in aquaria until 1916, when they were released into a pond, where they subsequently established a population before naturally dispersing into nearby water bodies (Reshetnikov 2004, Grabowska 2011). In 1948, additional Amur sleepers were introduced to Moscow for use in ornamental ponds by members of an expedition (Bogutskaya and Naseka 2002, Reshetnikov 2004). These fish escaped the ponds they were stocked into and spread to nearby waters in the city of Moscow and Moscow Province (Reshetnikov 2004).

Additionally, Amur sleepers were introduced to new areas when they were unintentionally shipped to fish farms in fish stocks such as silver carp ( Hypophthalmichthys molitrix ) and grass carp ( Ctenopharyngodon idella ). From these initial introductions, the Amur sleepers were able to expand from their native range through escape, release, and transfer between fish farms (Reshetnikov 2004)

004).

The Amur sleeper is an invasive species in western Russia and 14 additional countries: Mongolia, Belarus, Ukraine, Lithuania, Latvia, Estonia, Poland, Hungary, Romania, Slovakia, Serbia, Bulgaria, Moldova, and Croatia (Froese and Pauly 2014, Grabowska 2011). The Amur sleeper is established within the Baikal, Baltic, and Volga water basins of Europe and Asia (Bogutskaya and Naseka 2002). The species' nonnative range extends northward to Lake Plestsy in Arkhangelsk province (Russia), southward to Bulgaria, and westward to the Kis-Balaton watershed in Hungary (Grabowska 2011).

Biology

The Amur sleeper is a small- to medium-sized fish with a maximum body length of 25 cm (9.8 in) (Grabowska 2011) and weight of 250 g (0.6 lb) (Reshetnikov 2003). As with other fish species, both body length and weight vary with food supply, and larger Amur sleeper specimens have been reported from the nonnative range (Bogutskaya and Naseka 2002).

Body shape is fusiform with two dorsal fins, short pelvic fins, and rounded caudal fin (Grabowska 2011). The Amur sleeper has dark coloration of greenish olive, brownish gray, or dark green with dark spots and pale yellow to blue-green flecks (Grabowska 2011). Males are not easily discerned from females except during breeding season. Breeding males are darker (almost black) with bright blue-green spots and also have inflated areas on the head (Grabowska 2011).

The Amur sleeper lifespan is from 7 to 10 years

sleeper has dark coloration of greenish olive, brownish gray, or dark green with dark spots and pale yellow to blue-green flecks (Grabowska 2011). Males are not easily discerned from females except during breeding season. Breeding males are darker (almost black) with bright blue-green spots and also have inflated areas on the head (Grabowska 2011).

The Amur sleeper lifespan is from 7 to 10 years. Within native ranges, the fish rarely lives more than 4 years, whereas in nonnative ranges, the fish generally lives longer (Bogutskaya and Naseka 2002, Grabowska 2011). The fish reaches maturity between 2 and 3 years of age (Grabowska 2011) and has at least two spawning events per year.

The number of eggs per spawning event varies with female size. In the Wloclawski Reservoir, which is outside of the Amur sleeper's native range, the females produced an average of 7,766 eggs per female (range 1,963 to 23,479 eggs) (Grabowska et al. 2011). Male Amur sleepers are active in prenatal care by guarding eggs and aggressively defending the nest (Bogutskaya and Naseka 2002, Grabowska et al. 2011).

The Amur sleeper is a voracious, generalist predator that eats invertebrates (such as freshwater crayfish, shrimp, mollusks, and insects), amphibian tadpoles, and small fish (Bogutskaya and Naseka 2002). Reshetnikov (2003) found that the Amur sleeper significantly reduced species diversity of fishes and amphibians where it was introduced. In some small water bodies, Amur sleepers considerably decrease the number of species of aquatic macroinvertebrates, amphibian larvae, and fish species (Reshetnikov 2003, Pauly 2014, Kottelat and Freyhof 2007).

The predators of Amur sleepers include pike, perch, snakeheads ( Channa spp.), and gulls (Laridae) (Bogutskaya and Naseka 2002). In their native range, it is believed that this species is primarily controlled by snakeheads. Eggs and juveniles are fed on by a variety of insects (Bogutskaya and Naseka 2002)

phibian larvae, and fish species (Reshetnikov 2003, Pauly 2014, Kottelat and Freyhof 2007).

The Amur sleeper reportedly has high parasitic burdens of more than 40 parasite species (Grabowska 2011). The host-specific parasites, including Nippotaenia mogurndae and Gyrodactylus perccotti, have been transported to new areas along with the introduced Amur sleeper (Košuthová et al. 2004, Grabowska 2011). The cestode (tapeworm) Nippotaenia mogurndae was first reported in Europe in the River Latorica in east Slovakia in 1998, after this same river was invaded by the Amur sleeper (Košuthová et al. 2004). This parasite may be able to infect other fish species (Košuthová et al. 2008). Thus, the potential for the Amur sleeper to function as a parasitic host could aid in the transmission of parasites to new environments and potentially to new species (Košuthová et al. 2008, Košuthová et al. 2009).

Invasiveness

The Amur sleeper is considered one of the most widespread, invasive fish in European freshwater ecosystems within the last several decades (Copp et al. 2005a, Grabowska 2011, Reshetnikov and Ficetola 2011). Reshetnikov and Ficetola (2011) indicate that there are 13 expansion centers for this fish outside of its native range. Once this species has been introduced, it has proven to be capable of establishing sustainable populations (Reshetnikov 2004). Within the Vistula River (Poland), the Amur sleeper has averaged an annual expansion of its range by 88 kilometers (54.5 miles) per year (Grabowska 2011)

Reshetnikov and Ficetola (2011) indicate that there are 13 expansion centers for this fish outside of its native range. Once this species has been introduced, it has proven to be capable of establishing sustainable populations (Reshetnikov 2004). Within the Vistula River (Poland), the Amur sleeper has averaged an annual expansion of its range by 88 kilometers (54.5 miles) per year (Grabowska 2011). A recent study (Reshetnikov and Ficetola 2011) suggests many other regions of Europe and Asia, as well as northeastern United States and southeastern Canada, have suitable climates for the Amur sleeper and are at risk for an invasion.

The Amur sleeper demonstrates many of the strongest traits for invasiveness: It consumes a highly varied diet, is fast growing with a high reproductive potential, easily adapts to different environments, and has an expansive native range and proven history of increasing its nonnative range by itself and through human-mediated activities (Grabowska 2011). Where it is invasive, the Amur sleeper competes with native species for similar habitat and diet resources (Reshetnikov 2003, Kottelat and Freyhof 2007). This fish has also been associated with the decline in populations of the European mudminnow ( Umbra krameri ), crucian carp, and belica ( Leucaspius delineates ) (Grabowska 2011). This species hosts parasites that may be transmitted to native fish species when introduced outside of its native range (Košuthová et al. 2008, Košuthová et al. 2009).

European Perch (Perca fluviatilis)

The European perch was first described and cataloged by Linnaeus in 1758, and is part of the order Perciformes and family Percidae (ITIS 2014). European perch is the preferred common name, but this species may also be referred to as the Eurasian perch or redfin perch (Allen 2004, Froese and Pauly 2014).

Native Range and Habitat

The European perch inhabits a temperate climate (Riehl and Baensch 1991, Froese and Pauly 2014)

described and cataloged by Linnaeus in 1758, and is part of the order Perciformes and family Percidae (ITIS 2014). European perch is the preferred common name, but this species may also be referred to as the Eurasian perch or redfin perch (Allen 2004, Froese and Pauly 2014).

Native Range and Habitat

The European perch inhabits a temperate climate (Riehl and Baensch 1991, Froese and Pauly 2014). This species' native range extends throughout Europe and regions of Asia, including Afghanistan, Armenia, Azerbaijan, Georgia, Iran, Kazakhstan, Mongolia, Turkey, and Uzbekistan (Froese and Pauly 2014). The fish resides in a range of habitats that includes estuaries and freshwater lakes, ponds, rivers, and streams (Froese and Pauly 2014).

Nonnative Range and Habitat

The European perch has been intentionally introduced to several countries for recreational fishing, including Ireland (in the 1700s), Australia (in 1862), South Africa (in 1915), Morocco (in 1939), and Cyprus (in 1971) (FAO 2014, Froese and Pauly 2014). This species was introduced intentionally to Turkey for aquaculture (FAO 2004) and unintentionally to Algeria when it was included in the transport water with carp intentionally brought into the country (Kara 2012, Froese and Pauly 2014). European perch have also been introduced to China (in the 1970s), Italy (in 1860), New Zealand (in 1867), and Spain (no date) for unknown reasons (FAO 2014). In Australia, this species was first introduced as an effort to introduce wildlife familiar to European colonizers (Arthington and McKenzie 1997). The European perch was first introduced to Tasmania in 1862, Victoria in 1868, and to southwest Western Australia in 1892 and the early 1900s (Arthington and McKenzie 1997). This species has now invaded western Victoria, New South Wales, Tasmania, Western Australia, and South Australian Gulf Coast (NSW DPI 2013). In the 1980s, the European perch invaded the Murray River in southwestern Australia (Hutchison and Armstrong 1993)

introduced to Tasmania in 1862, Victoria in 1868, and to southwest Western Australia in 1892 and the early 1900s (Arthington and McKenzie 1997). This species has now invaded western Victoria, New South Wales, Tasmania, Western Australia, and South Australian Gulf Coast (NSW DPI 2013). In the 1980s, the European perch invaded the Murray River in southwestern Australia (Hutchison and Armstrong 1993).

Biology

The European perch has an average body length of 25 cm (10 in) with a maximum length of 60 cm (24 in) (Kottelat and Freyhof 2007, Froese and Pauly 2014j) and an average body weight of 1.2 kg (2.6 lb) with a maximum weight of 4.75 kg (10.5 lb) (Froese and Pauly 2014). European perch color varies with habitat. Fish in well-lit shallow habitats tend to be darker, whereas fish residing in poorly lit areas tend to be lighter. These fish may also absorb carotenoids (nutrients that cause color) from their diet (crustaceans), resulting in reddish-yellow color (Allen 2004). Male fish are not easily externally differentiated from female fish (Allen 2004).

The European perch lives up to 22 years (Froese and Pauly 2014), although the average is 6 years (Kottelat and Freyhof 2007). This fish may participate in short migrations prior to spawning in February through July, depending on latitude and altitude (Kottelat and Freyhof 2007). Female fish are sexually mature at 2 to 4 years and males at 1 to 2 years (Kottelat and Freyhof 2007).

The European perch is a generalist predator with a diet of zooplankton, macroinvertebrates (such as copepods and crustaceans), and small fish (Kottelat and Freyhof 2007, Froese and Pauly 2014).

The European perch can also carry the OIE-notifiable disease epizootic haematopoietic necrosis (EHN) virus Bidyanus bidyanus ) and Murray cod ( Maccullochella peelii )) are extremely susceptible to the virus and have had significant population declines over the past decades with the continued invasion of European perch (NSW DPI 2013)

small fish (Kottelat and Freyhof 2007, Froese and Pauly 2014).

Invasiveness

The European perch has been introduced to many new regions through fish stocking for recreational use. The nonnative range has also expanded as the fish has swum to new areas through connecting waterbodies (lakes, river, and streams within the same watershed). In New South Wales, Australia, these fish are a serious pest and are listed as Class 1 noxious species (NSW DPI 2013). These predatory fish have been blamed for the local extirpation of the mudminnow ( Galaxiella munda ) (Moore 2008, ISSG 2010) and depleted populations of native invertebrates and fish (Moore 2008). This species reportedly consumed 20,000 rainbow trout ( Oncorhynchus mykiss ) fry from an Australian reservoir in less than 3 days (NSW DPI 2013). The introduction of these fish in New Zealand and China has severely altered native freshwater communities (Closs et al. 2003). European perch form dense populations, forcing them to compete amongst each other for a reduced food supply. This results in stunted fish that are less appealing to the recreational fishery (NSW DPI 2013).

Zander (Sander lucioperca)

The zander was first described and catalogued by Linnaeus in 1758, and belongs to the order Perciformes and family Percidae (ITIS 2014). Although its preferred common name in the United States is the zander, this fish species is also called the pike-perch and European walleye (Godard and Copp 2011, Froese and Pauly 2014).

Native Range and Habitat

The zander's native range includes the Caspian Sea, Baltic Sea, Black Sea, Aral Sea, North Sea, and Aegean Sea basins

belongs to the order Perciformes and family Percidae (ITIS 2014). Although its preferred common name in the United States is the zander, this fish species is also called the pike-perch and European walleye (Godard and Copp 2011, Froese and Pauly 2014).

Native Range and Habitat

The zander's native range includes the Caspian Sea, Baltic Sea, Black Sea, Aral Sea, North Sea, and Aegean Sea basins. In Asia, this fish is native to Afghanistan, Armenia, Azerbaijan, Georgia, Iran, Kazakhstan, and Uzbekistan. In Europe, the zander is native to much of eastern Europe (Albania, Austria, Czech Republic, Estonia, Germany, Greece, Hungary, Latvia, Lithuania, Moldova, Poland, Romania, Russia, Serbia, Slovakia, Ukraine, and Serbia and Montenegro) and the Scandinavian Peninsula (Finland, Norway, and Sweden) (Godard and Copp 2011, Froese and Pauly 2014). The northernmost records of native populations are in Finland up to 64 °N (Larsen and Berg 2014).

The zander resides in brackish coastal estuaries and freshwater rivers, lakes, and reservoirs. The species prefers turbid, slightly eutrophic waters with high dissolved oxygen concentrations (Godard and Copp 2011). The zander can survive in salinities up to 20 parts per thousand (ppt), but prefers environments with salinities less than 12 ppt and requires less than 3 ppt for reproduction (Larsen and Berg 2014).

Nonnative Range and Habitat

The zander has been repeatedly introduced outside of its native range for recreational fishing and aquaculture and also to control cyprinids (Godard and Copp 2011, Larsen and Berg 2014). This species has been introduced to much of Europe, parts of Asia (China, Kyrgyzstan, and Turkey), and northern Africa (Algeria, Morocco, and Tunisia). Within Europe, the zander has been introduced to Belgium, Bulgaria, Croatia, Cyprus, Denmark, France, Italy, the Netherlands, Portugal, the Azores, Slovenia, Spain, Switzerland, and the United Kingdom (Godard and Copp 2011, Froese and Pauly 2014)

. This species has been introduced to much of Europe, parts of Asia (China, Kyrgyzstan, and Turkey), and northern Africa (Algeria, Morocco, and Tunisia). Within Europe, the zander has been introduced to Belgium, Bulgaria, Croatia, Cyprus, Denmark, France, Italy, the Netherlands, Portugal, the Azores, Slovenia, Spain, Switzerland, and the United Kingdom (Godard and Copp 2011, Froese and Pauly 2014). In Denmark, although the zander is native, stocking is not permitted to prevent the species from being introduced into lakes and rivers where it is not presently found and where introduction is not desirable (Larsen and Berg 2014).

The zander has been previously introduced to the United States. Juvenile zanders were stocked into Spiritwood Lake (North Dakota) in 1989 for recreational fishing (Fuller et al. 1999, Fuller 2009, USGS NAS 2014). Although previous reports indicated that zanders did not become established in Spiritwood Lake, there have been documented reports of captured juvenile zanders from this lake (Fuller 2009). In 2009, the North Dakota Game and Fish Department reported a small, established population of zanders within Spiritwood Lake (Fuller 2009), and a zander caught in 2013 was considered the State record (North Dakota Game and Fish 2013).

Biology

The zander has an average body length of 50 cm (1.6 ft) and maximum body length of 100 cm (3.3 ft). The maximum published weight is 20 kg (44 lb) (Froese and Pauly 2013). The zander has a long slender body with yellow-gray fins and dark bands running from the back down each side (Godard and Copp 2011).

The zander's age expectancy is inversely correlated to its body growth rate. Slower-growing zanders may live up to 20 to 24 years, whereas faster-growing fish may live only 8 to 9 years (Godard and Copp 2011). Female zanders typically spawn in April and May and produce approximately 150 to 400 eggs per gram of body mass. After spawning, male zanders protect the nest and fan the eggs with the pectoral fins (Godard and Copp 2011)

inversely correlated to its body growth rate. Slower-growing zanders may live up to 20 to 24 years, whereas faster-growing fish may live only 8 to 9 years (Godard and Copp 2011). Female zanders typically spawn in April and May and produce approximately 150 to 400 eggs per gram of body mass. After spawning, male zanders protect the nest and fan the eggs with the pectoral fins (Godard and Copp 2011).

The zander is piscivorous, and its diet includes smelt ( Osmerus eperlanus ), ruffe ( Gymnocephalus cernuus ), European perch, vendace ( Coregonus albula ), roach, and other zanders (Kangur and Kangur 1998).

Several studies have found that zanders can be hosts for multiple parasites (Godard and Copp 2011). The nematode Anisakis, which is known to infect humans through fish consumption, has been documented in the zander (Eslami and Mokhayer 1977, Eslami et al. 2011). A study in the Polish section of Vistula Lagoon found 26 species of parasites associated with the zander, which was more than any of the other 15 fish species studied (Rolbiecki 2002, 2006).

Invasiveness

The zander has been intentionally introduced numerous times for aquaculture, recreational fishing, and occasionally for biomanipulation to remove unwanted cyprinids (Godard and Copp 2011). Biomanipulation is the management of an ecosystem by adding or removing species. The zander also migrates for spawning, further expanding its invasive range. It is a predatory fish that is well-adapted to turbid water and low-light habitats (Sandström and Karås 2002). The zander competes with and preys on native fish populations. The zander is also a vector for the trematode Bucephalus polymorphus, which has been linked to a decrease in native French cyprinid populations (Kvach and Mierzejewska 2011).

Wels Catfish (Silurus glanis)

The wels catfish was first described and cataloged by Linnaeus in 1758, and belongs to the order Siluriformes and family Siluridae (ITIS 2014)

petes with and preys on native fish populations. The zander is also a vector for the trematode Bucephalus polymorphus, which has been linked to a decrease in native French cyprinid populations (Kvach and Mierzejewska 2011).

Wels Catfish (Silurus glanis)

The wels catfish was first described and cataloged by Linnaeus in 1758, and belongs to the order Siluriformes and family Siluridae (ITIS 2014). The preferred common name is the wels catfish, but this fish is also called the Danube catfish, European catfish, and sheatfish (Rees 2012, Froese and Pauly 2014).

Native Range and Habitat

The wels catfish inhabits a temperate climate (Baensch and Riehl 2004). The species is native to eastern Europe and

Nonnative Range and Habitat

The wels catfish was introduced to the United Kingdom and western Europe during the 19th century. The species was first introduced to England in 1880 for recreational fishing at the private Bedford manor estate of Woburn Abbey. Since then, wels catfish have been stocked both legally and illegally into many lakes and are now widely distributed throughout the United Kingdom (Rees 2012). This species was introduced to Spain, Italy, and France for recreational fishing and aquaculture (Rees 2012). Wels catfish were introduced to the Netherlands as a substitute predator to control cyprinid fish populations (De Groot 1985) after the native pike were overfished. The wels catfish has also been introduced to Algeria, Belgium, Bosnia-Hercegovina, China, Croatia, Cyprus, Denmark, Finland, Portugal, Syria, and Tunisia, although they are not known to be established in Algeria or Cyprus (Rees 2012).

Biology

The wels catfish commonly grows to 3 m (9.8 ft) in body length with a maximum length of 5 m (16.4 ft) and is Europe's largest freshwater fish (Rees 2012). The maximum published weight is 306 kg (675 lb) (Rees 2012).

This species has a strong, elongated, scaleless, mucus-covered body with a flattened tail

although they are not known to be established in Algeria or Cyprus (Rees 2012).

Biology

This species has a strong, elongated, scaleless, mucus-covered body with a flattened tail. The body color is variable but is generally mottled with dark greenish-black and creamy-yellow sides. Wels catfishes possess six barbels; two long ones on each side of the mouth, and four shorter ones under the jaw (Rees 2012).

Although the maximum reported age is 80 years (Kottelat and Freyhof 2007), the average lifespan of a wels catfish is 15 to 30 years. This species becomes sexually mature at 3 to 4 years of age. Nocturnal spawning occurs annually and aligns with optimal temperature and day length between April and August (Kottelat and Freyhof 2007, Rees 2012). The number of eggs produced per female, per year is highly variable, and depends on age, size, geographic location, and other factors. Studies in Asia have documented egg production of a range of approximately 8,000 to 467,000 eggs with the maximum reported being 700,000 eggs (Copp et al. 2009). Male fish will guard the nest, repeatedly fanning their tails to ensure proper ventilation until the eggs hatch 2 to 10 days later (Copp et al. 2009). Young catfish develop quickly and, on average, achieve a 38- to 48-cm (15- to 19-in) total length within their first year (Copp et al. 2009).

This species is primarily nocturnal and will exhibit territorial behavior (Copp et al. 2009). The wels catfish is a solitary ambush predator but is also an opportunistic scavenger of dead fish (Copp et al. 2009). Juvenile catfish typically eat invertebrates. Adult catfish are generalist predators with a diet that includes fish (at least 55 species), crayfish, small mammals (such as rodents), and waterfowl (Copp et al. 2009, Rees 2012)

d will exhibit territorial behavior (Copp et al. 2009). The wels catfish is a solitary ambush predator but is also an opportunistic scavenger of dead fish (Copp et al. 2009). Juvenile catfish typically eat invertebrates. Adult catfish are generalist predators with a diet that includes fish (at least 55 species), crayfish, small mammals (such as rodents), and waterfowl (Copp et al. 2009, Rees 2012). Wels catfish have been observed beaching themselves to prey on land birds located on river banks (Cucherousset 2012).

Juvenile wels catfish can carry the highly infectious SVC (Hickley and Chare 2004). This disease is recognized worldwide and is classified as a notifiable animal disease by the World Organisation for Animal Health (OIE 2014). The wels catfish is also a host to at least 52 parasites, including: Trichodina siluri, Myxobolus miyarii, Leptorhynchoides plagicephalus and Pseudotracheliastes stellifer, all of which may be detrimental to native fish survival (Copp et al. 2009).

Invasiveness

The wels catfish is a habitat-generalist that tolerates poorly oxygenated waters and has been repeatedly introduced to the United Kingdom and western Europe for aquaculture, research, pest control, and recreational fishing (Rees 2012). Although this species has been intentionally introduced for aquaculture and fishing, it has also expanded its nonnative range by escaping from breeding and stocking facilities (Rees 2012). This species is tolerant of a variety of warm-water habitats, including those with low dissolved oxygen levels. The invasive success of the wels catfish will likely be further enhanced with the predicted increase in water temperature with climate change (2 to 3 °C by 2050) (Rahel and Olden 2008, Britton et al. 2010a).

The major risks associated with invasive wels catfish to the native fish population include disease transmission (SVC) and competition for habitat and prey species (Rees 2012)

oxygen levels. The invasive success of the wels catfish will likely be further enhanced with the predicted increase in water temperature with climate change (2 to 3 °C by 2050) (Rahel and Olden 2008, Britton et al. 2010a).

The major risks associated with invasive wels catfish to the native fish population include disease transmission (SVC) and competition for habitat and prey species (Rees 2012). This fish species also excretes large amounts of phosphorus and nitrogen (estimated 83- to 286-fold and 17- to 56-fold, respectively) (Boulêtreau et al. 2011) into the ecosystem and consequently greatly disrupts nutrient cycling and transport (Schaus et al. 1997, McIntyre et al. 2008, Boulêtreau et al. 2011). Because of their large size, multiple wels catfish in one location magnify these effects and can greatly increase algae and plant growth (Boulêtreau et al. 2011), which reduces water quality.

Common Yabby (Cherax destructor)

Unlike the 10 fish in this rule, the yabby is a crayfish. Crayfish are invertebrates with hard shells. They can live and breathe underwater, and they crawl along the substrate on four pairs of walking legs (Holdich and Reeve 1988); the pincers are considered another pair of walking legs. The common yabby was first described and cataloged by Clark in 1936 and belongs to the phylum Arthropoda, order Decapoda, and family Parastacidae (ITIS 2014). This freshwater crustacean may also be called the yabby or the common crayfish. The term “yabby” is also commonly used for crayfish in Australia.

Native Range and Habitat

The common yabby is native to eastern Australia and extends from South Australia, northward to southern parts of the Northern Territory, and eastward to the Great Dividing Range (Eastern Highlands) (Souty-Grosset et al. 2006, Gherardi 2011a).

The common yabby inhabits temperate and tropical climates

h. The term “yabby” is also commonly used for crayfish in Australia.

Native Range and Habitat

The common yabby inhabits temperate and tropical climates. In aquaculture, the yabby tolerates the wide range of water temperatures from 1 to 35 °C (34 to 95 °F) and with an optimal water temperature range of 20 to 25 °C (68 to 77 °F) (Withnall 2000). Growth halts below 15 °C (59 °F) and above 34 °C (93 °F), partial hibernation (decreased metabolism and feeding) occurs below 16 °C (61 °F), and death occurs when temperatures rise above 36 °C (97 °F) (Gherardi 2011a). The yabby can also survive drought for several years by sealing itself in a deep burrow (burrows well over 5 meters (m; 16.4 feet (ft)) have been found) and aestivating (the crayfish's respiration, pulse, and digestion nearly cease) (NSW DPI 2015).

This species can tolerate a wide range of dissolved oxygen concentrations and salinities (Mills and Geddes 1980) but prefers salinities less than 8 ppt (Withnall 2000, Gherardi 2011a). Growth ceases at salinities above 8 ppt (Withnall 2000). This correlates with Beatty's (2005) study where all yabbies

The common yabby resides in a variety of habitats, including desert mound springs, alpine streams, subtropical creeks, rivers, billabongs (small lake, oxbow lake), temporary lakes, swamps, farm dams, and irrigation channels (Gherardi 2011a). The yabby is found in mildly turbid waters and muddy or silted bottoms. The common yabby digs burrows that connect to waterways (Withnall 2000). Burrowing can result in unstable and collapsed banks (Gherardi 2011a)

ding desert mound springs, alpine streams, subtropical creeks, rivers, billabongs (small lake, oxbow lake), temporary lakes, swamps, farm dams, and irrigation channels (Gherardi 2011a). The yabby is found in mildly turbid waters and muddy or silted bottoms. The common yabby digs burrows that connect to waterways (Withnall 2000). Burrowing can result in unstable and collapsed banks (Gherardi 2011a).

Nonnative Range and Habitat

The common yabby is commercially valuable and is frequently imported by countries for aquaculture, aquariums, and research (Gherardi 2011a); it is raised in aquaculture as food for humans (NSW DPI 2015). This species has spread throughout Australia, and its nonnative range extends to New South Wales east of the Great Dividing Range, Western Australia, and Tasmania. This crayfish species was introduced to Western Australia in 1932 for commercial aquaculture from where it escaped and established in rivers and irrigation dams (Souty-Grosset et al. 2006). Outside of Australia, this species has been introduced into Italy and Spain where it has become established (Gherardi 2011a). The common yabby has been introduced to China, South Africa, and Zambia for aquaculture (Gherardi 2011a) but has not become established in the wild in those countries. The first European introduction occurred in 1983, when common yabbies were transferred from a California farm to a pond in Girona, Catalonia, Spain (Souty-Grosset et al. 2006). This crayfish species became established in Zaragoza Province, Spain after being introduced in 1984 or 1985 (Souty-Grosset et al. 2006).

Biology

The common yabby has been described as a “baby lobster” because of its relatively large body size for a crayfish and because of its unusually large claws. Yabbies have a total body length up to 15 cm (6 in) with a smooth external carapace (exoskeleton) (Souty-Grosset et al. 2006, Gherardi 2011a). Body color can vary with geographic location, season, and water conditions (Withnall 2000). Most captive cultured yabbies are blue-gray, whereas wild yabbies may be green-beige to black (Souty-Grosset et al. 2006,Withnall 2000). Yabbies in the aquarium trade can be blue or white and go by the names blue knight and white ghost (LiveAquaria.com 2014a, b).

Most common yabbies live 3 years with some living up to 6 years (Souty-Grosset et al. 2006, Gherardi 2011a). Females can be distinguished from males by the presence of gonopores at the base of the third pair of walking legs; while males have papillae at the base of the fifth pair of walking legs (Gherardi 2011a). The female yabby becomes sexually mature before it is 1 year old (Gherardi 2011a). Spawning is dependent on day length and water temperatures. When water temperatures rise above 15 °C (59 °F), the common yabby will spawn from early spring to mid-summer. When the water temperature is consistently between 18 and 20 °C (64 to 68 °F) with daylight of more than 14 hours, the yabby will spawn up to five times a year (Gherardi 2011a). Young females produce 100 to 300 eggs per spawning event, while older (larger) females can produce up to 1,000 eggs (Withnall 2000). Incubation is also dependent on water temperature and typically lasts 19 to 40 days (Withnall 2000).

The common yabby grows through molting, which is shedding of the old carapace and then growing a new one (Withnall 2000). A juvenile yabby will molt every few days, whereas, an adult yabby may molt only annually or semiannually (Withnall 2000).

The common yabby is an opportunistic omnivore with a carnivorous summer diet and herbivorous winter diet (Beatty 2005)

s 19 to 40 days (Withnall 2000).

The common yabby is an opportunistic omnivore with a carnivorous summer diet and herbivorous winter diet (Beatty 2005). The diet includes fish ( Gambusia holbrooki ), plant material, detritus, and zooplankton. The yabby is also cannibalistic, especially where space and food are limited (Gherardi 2011a).

The common yabby is affected by at least ten parasites (Jones and Lawrence 2001), including the crayfish plague (caused by Aphanomyces astaci ), burn spot disease, Psorospermium sp. (a parasite), and thelohaniasis (Jones and Lawrence 2001, Souty-Grosset et al. 2006, Gherardi 2011a). The crayfish plague is an OIE-reportable disease. Twenty-three bacteria species have been found in the yabby as well (Jones and Lawrence 2001).

Invasiveness

The common yabby has a quick growth and maturity rate, high reproductive rate, and generalist diet. These attributes, in addition to the species' tolerance for a wide range of freshwater habitats, make the common yabby an efficient invasive species. Additionally, the invasive range of the common yabby is expected to expand with climate change (Gherardi 2011a). Yabbies can also live on land and travel long distances by walking between water bodies (Gherardi 2011b:129).

The common yabby may reduce biodiversity through competition and predation with native species. In its nonnative range, the common yabby has proven to out-compete native crayfish species for food and habitat (Beatty 2006, Gherardi 2011a). Native freshwater crayfish species are also at risk from parasitic infections from the common yabby (Gherardi 2011a).

Summary of the Presence of the 11 Species in the United States

Only one of the 11 species, the zander, is present in the wild within the United States

e range, the common yabby has proven to out-compete native crayfish species for food and habitat (Beatty 2006, Gherardi 2011a). Native freshwater crayfish species are also at risk from parasitic infections from the common yabby (Gherardi 2011a).

Summary of the Presence of the 11 Species in the United States

Only one of the 11 species, the zander, is present in the wild within the United States. There has been a small established population of zander within Spiritwood Lake (North Dakota) since 1989. Crucian carp were reportedly introduced to Chicago lakes and lagoons during the early 1900s. Additionally, Nile perch were introduced to Texas reservoirs between 1978 and 1985. However, neither the crucian carp nor the Nile perch established populations, and these two species are no longer present in the wild in U.S. waters. These examples demonstrate that the interest may exist for future attempts at introductions into the United States for these and the other species. Because these species are not yet present in the United States, except for one species in one lake, but have been introduced, become established, and been documented as causing harm in countries outside of their native ranges, regulating them now to prohibit importation and interstate transportation and thus prevent the species' likely introduction and establishment in the wild and likely harm to human beings, to the interests of agriculture, or to wildlife or wildlife resources is critical to preventing their injurious effects in the United States.

Rapid Screening

The first step that the Service performed in selecting species to evaluate for listing as injurious was to prepare a rapid screen

thus prevent the species' likely introduction and establishment in the wild and likely harm to human beings, to the interests of agriculture, or to wildlife or wildlife resources is critical to preventing their injurious effects in the United States.

Rapid Screening

The first step that the Service performed in selecting species to evaluate for listing as injurious was to prepare a rapid screen. We asked, without doing a full risk assessment on each potential species, how could we quickly assess which species out of thousands of foreign species not yet found in the United States should be categorized as high-risk of invasiveness? Our method was to conduct rapid screenings and compile the information in Ecological Risk Screening Summaries (ERSS) for each species to determine the Overall Risk Assessment of each species. More information on the ERSS process and its peer review is posted online at http://www.fws.gov/ and http://www.fws.gov/science/pdf/ERSS-Peer-Review-Response-report.pdf. The ERSS reports also served to subsequently provide some of the information for the injurious wildlife evaluation criteria. This procedure incorporates scores for the history of invasiveness, climate matching between the species' range (native and invaded ranges) and the United States, and certainty of assessment to determine an Overall Risk Assessment score.

For the 11 species under consideration, all species have a high risk for history of invasiveness.

history of invasiveness.

For the 11 species considered, overall climate match ranged from medium for the Nile perch, to high for the remaining nine fish and one crayfish species. The climate match analysis (Australian Bureau of Rural Sciences 2010) incorporates 16 climate variables to calculate climate scores that can be used to calculate a Climate 6 ratio (see USFWS 2014 for additional details). Using the Climate 6 ratio, species can be categorized as having a low (0.000 to 0.005), medium (greater than 0.005 to less than 0.103), or high (greater than 0.103) climate match (Bomford 2008; USFWS 2014). This climate matching method is used by some projects funded under the Great Lakes Restoration Initiative to direct efforts to prevent the invasion of aquatic species in the Great Lakes. For this proposed rule, the Service expanded the source ranges (native and nonnative distribution) of several species for the climate match from those listed in the ERSSs. The revised source ranges included additional locations referenced in FishBase (Froese and Pauly 2010), the CABI ISC, and the Handbook of European Freshwater Fishes (Kottelat and Freyhof 2007). Additional source points were also specifically selected for the stone moroko's distribution within the United Kingdom (Pinder et al. 2005). There were no revisions to the climate match for the Nile perch, Amur sleeper, or common yabby. The target range for the climate match included the States, District of Columbia, Guam, Puerto Rico, and the U.S. Virgin Islands.

For the 11 species under consideration, the certainty of assessment (with sufficient and reliable information) was high for all species.

and reliable information) was high for all species.

The Overall Risk Assessment, which is determined from a combination of scores for history of invasiveness, climate match, and certainty of assessment, was found to be high for all 11 species. A high score for the Overall Risk Assessment indicates that the assessed species would be a greater threat of invasiveness than a species with a low score. The Amur sleeper, crucian carp, Eurasian minnow, European perch, Nile perch, Prussian carp, roach, stone moroko, wels catfish, zander, and common yabby are high-risk species.

Injurious Wildlife Evaluation Criteria

Once we determined that the 11 species were good candidates for evaluating because of their invasive risk, we used the criteria below to evaluate whether a species qualifies as injurious under the Act. The analysis using these criteria serve as a general basis for the Service's regulatory decision regarding all injurious wildlife listings. Biologists within the Service evaluated both the factors that contribute to and the factors that reduce the likelihood of injuriousness. These factors were developed by the Service.

(1) Factors that contribute to being considered injurious:

• The likelihood of release or escape;

• Potential to survive, become established, and spread;

• Impacts on wildlife resources or ecosystems through hybridization and competition for food and habitats, habitat degradation and destruction, predation, and pathogen transfer;

• Impacts to endangered and threatened species and their habitats;

• Impacts to human beings, forestry, horticulture, and agriculture; and

• Wildlife or habitat damages that may occur from control measures.

pread;

• Impacts on wildlife resources or ecosystems through hybridization and competition for food and habitats, habitat degradation and destruction, predation, and pathogen transfer;

• Impacts to endangered and threatened species and their habitats;

• Impacts to human beings, forestry, horticulture, and agriculture; and

• Wildlife or habitat damages that may occur from control measures.

(2) Factors that reduce the likelihood of the species being considered as injurious:

• Ability to prevent escape and establishment;

• Potential to eradicate or manage established populations (for example, making organism sterile);

• Ability to rehabilitate disturbed ecosystems;

• Ability to prevent or control the spread of pathogens or parasites; and

• Any potential ecological benefits to introduction.

For this proposed rule, a hybrid is defined as any progeny (offspring) from any cross involving a parent from one of the 11 species. These progeny would likely have the same or similar biological characteristics of the parent species (Ellstrand and Schierenbeck 2000, Mallet 2007), which, according to our analysis, would indicate that they are injurious to human beings, to the interests of agriculture, or to wildlife or wildlife resources of the United States.

Factors That Contribute to Injuriousness for Crucian Carp

Current Nonnative Occurrences

This species is not currently found within the United States. The crucian carp has been introduced and become established in Croatia, Greece, France, Italy, and England (Crivelli 1995, Kottelat and Freyhof 2007).

Potential Introduction and Spread

Potential pathways of introduction into the United States include stocking for recreational fishing and through misidentified shipments of ornamental fish (Wheeler 2000, Hickley and Chare 2004, Innal and Erk'ahan 2006, Sayer et al. 2011). Additionally, crucian carp may be misidentified as other carp species, such as the Prussian carp or common carp, and thus they are likely underreported (Godard and Copp 2012)

hways of introduction into the United States include stocking for recreational fishing and through misidentified shipments of ornamental fish (Wheeler 2000, Hickley and Chare 2004, Innal and Erk'ahan 2006, Sayer et al. 2011). Additionally, crucian carp may be misidentified as other carp species, such as the Prussian carp or common carp, and thus they are likely underreported (Godard and Copp 2012).

The crucian carp prefers a temperate climate (as found in much of the United States) and tolerates high summer air temperatures (up to 35 °C (95 °F)) and can survive in poorly oxygenated waters (Godard and Copp 2012). The crucian carp has an overall high climate match with a Climate 6 ratio of 0.355. This species has a high climate match throughout much of the Great Lakes region, southeastern United States, and southern Alaska and Hawaii. Low matches occur in the desert Southwest.

If introduced, the crucian carp is likely to spread and become established in the wild due to its ability to be a habitat and diet generalist and adapt to new environments, to its long life span (maximum 10 years), and to its ability to establish outside of the native range.

Potential Impacts to Native Species (Including Threatened and Endangered Species)

As mentioned previously, the crucian carp can compete with native fish species, alter the health of freshwater habitats, hybridize with other invasive and injurious carp species, and serve as a vector of the OIE-reportable fish disease SVC (Ahne et al. 2002, Godard and Copp 2012). The introduction of crucian carp to the United States could result in increased competition with native fish species for food resources (Welcomme 1988). The crucian carp consumes a variety of food resources, including plankton, benthic invertebrates, plant materials, and detritus (Kottelat and Freyhof 2007). With this varied diet, crucian carp would directly compete with numerous native species

). The introduction of crucian carp to the United States could result in increased competition with native fish species for food resources (Welcomme 1988). The crucian carp consumes a variety of food resources, including plankton, benthic invertebrates, plant materials, and detritus (Kottelat and Freyhof 2007). With this varied diet, crucian carp would directly compete with numerous native species.

The crucian carp has a broad climate match throughout the country, and thus its introduction and establishment

The ability of crucian carp to hybridize with other species of Cyprinidae (including common carp) may exacerbate competition over limited food resources and ecosystem changes, and thus, further challenge native species (including native threatened or endangered fish species).

Crucian carp harbor the fish disease SVC and additional parasitic infections. Although SVC also infects other carp species, this disease can also be transmitted through the water column to native fish species causing fish mortalities. Mortality rates from SVC have been documented up to 70 percent among juvenile fish and 30 percent among adult fish (Ahne et al. 2002). Therefore, as a vector of SVC, this fish species may also be responsible for reduced wildlife diversity. Crucian carp may outcompete native fish species, thus replacing them in the trophic scheme. Large populations of crucian carp can result in considerable predation on aquatic plants and invertebrates. Changes in ecosystem cycling and wildlife diversity may have negative effects on the aesthetic, recreational, and economic benefits of the environment.

Potential Impacts to Humans

We have no reports of the crucian carp being directly harmful to humans.

Potential Impacts to Agriculture

ts of the environment.

Potential Impacts to Humans

We have no reports of the crucian carp being directly harmful to humans.

Potential Impacts to Agriculture

The introduction of crucian carp is likely to affect agriculture by contaminating commercial aquaculture. This fish species can harbor Spring Viremia of Carp (SVC), which can infect numerous fish species, including common carp, koi ( C. carpio ), crucian carp, bighead carp ( Hypophthalmichthys nobilis ), silver carp, and grass carp (Ahne et al. 2002). This disease can cause serious fish mortalities, and thus can detrimentally affect the productivity of several species in commercial aquaculture facilities, including grass carp, goldfish, koi, fathead minnows ( Pimephales promelas ), and golden shiner ( Notemigonus crysoleucas ) (Ahne et al. 2002, Goodwin 2002).

Factors That Reduce or Remove Injuriousness for Crucian Carp

Control

Lab experiments indicate that the piscicide rotenone (a commonly used natural fish poison) could be used to control a crucian carp population (Ling 2003). However, rotenone is not target-specific (Wynne and Masser 2010). Depending on the applied concentration, rotenone kills other aquatic species in the water body. Some fish species are more susceptible than others, and the use of this piscicide may result in killing native species. Control measures that would harm other wildlife are not recommended as mitigation plans to reduce the injurious characteristics of this species and therefore do not meet control measures under the Injurious Wildlife Evaluation Criteria.

No other control methods are known for the crucian carp, but several other control methods are currently being used or are in development for introduced and invasive carp species of other genera. For example, the U.S. Geological Survey (USGS) is developing a method to orally deliver a piscicide (Micromatrix) specifically to invasive bighead carp ( Hypophthalmichthys nobilis ) and silver carp (Luoma 2012)

r control methods are known for the crucian carp, but several other control methods are currently being used or are in development for introduced and invasive carp species of other genera. For example, the U.S. Geological Survey (USGS) is developing a method to orally deliver a piscicide (Micromatrix) specifically to invasive bighead carp ( Hypophthalmichthys nobilis ) and silver carp (Luoma 2012). This developmental control measure is expensive and not guaranteed to prove effective for any carps.

Potential Ecological Benefits for Introduction

We are not aware of any documented ecological benefits for the introduction of crucian carp.

Factors That Contribute to Injuriousness for Eurasian Minnow

Current Nonnative Occurrences

This species is not currently found within the United States. The Eurasian minnow was introduced to new waterways in its native range of Europe and Asia (Sandlund 2008). This fish species has been introduced to new locations in Norway outside of its native range there (Sandlund 2008, Hesthagen and Sandlund 2010).

Potential Introduction and Spread

Likely pathways of introduction include release or escape when used as live bait, unintentional inclusion in the transport water of intentionally stocked fish (often with salmonids), and intentional introduction for vector (insect) management (Sandlund 2008). Once introduced, this species can spread and establish in nearby waterways.

The Eurasian minnow prefers a temperate climate (Froese and Pauly 2013). This minnow is capable of establishing in a variety of aquatic ecosystems ranging from freshwater to brackish water (Sandlund 2008). The Eurasian minnow has an overall high climate match with a Climate 6 ratio of 0.397. The highest climate matches are in the northern States, including Alaska. The lowest climate matches are in the Southeast and Southwest

a temperate climate (Froese and Pauly 2013). This minnow is capable of establishing in a variety of aquatic ecosystems ranging from freshwater to brackish water (Sandlund 2008). The Eurasian minnow has an overall high climate match with a Climate 6 ratio of 0.397. The highest climate matches are in the northern States, including Alaska. The lowest climate matches are in the Southeast and Southwest.

If introduced to the United States, the Eurasian minnow is highly likely to spread and become established in the wild due to this species' traits as a habitat generalist and generalist predator, with adaptability to new environments, high reproductive potential, long life span, extraordinary mobility, social nature, and proven invasiveness outside of the species' native range.

Potential Impacts to Native Species (Including Endangered and Threatened Species)

Introduction of the Eurasian minnow can affect native species through several mechanisms, including competition over resources, predation, and parasite transmission. Introduced Eurasian minnows have a more serious effect in waters with fewer species than those waters with a more developed, complex fish community (Museth et al. 2007). In Norway, dense populations of the Eurasian minnow have resulted in an average 35 percent reduction in recruitment and growth rates in native brown trout (Museth et al. 2007). In the United States, introduced Eurasian minnow populations would likely compete with and adversely affect Atlantic salmon, State-managed brown trout, and other salmonid species.

ulations would likely compete with and adversely affect Atlantic salmon, State-managed brown trout, and other salmonid species.

Eurasian minnow introductions have also disturbed freshwater benthic invertebrate communities (Næstad and Brittain 2010). Increased predation by Eurasian minnows has led to shifts in invertebrate populations and changes in benthic diversity (Hesthagen and Sandlund 2010). Many of the invertebrates consumed by the Eurasian minnow are also components of the diet of the brown trout, thus exacerbating competition between the introduced Eurasian minnow and brown trout (Hesthagen and Sandlund 2010). Additionally, Eurasian minnows have been shown to compete with brown trout (Hesthagen and Sandlund 2010) and to consume vendace (a salmonid) larvae (Huusko and Sutela 1997). If introduced, the Eurasian minnow's diet may include the larvae of U.S. native salmonids, including Atlantic salmon, sockeye salmon ( Oncorhynchus nerka ), and trout species ( Salvelinus spp.).

The Eurasian minnow serves as a host to parasites, such as Gyrodactylus aphyae, that it can transmit to other fish species, including salmon and trout (Zietara et al. 2008). Once introduced, these parasites would likely spread to native salmon and trout species. Gyrodactylus species may cause high fish mortality (Bakke et al. 1992).

Potential Impacts to Humans

We have no reports of the Eurasian minnow being harmful to humans.

Potential Impacts to Agriculture

The Eurasian minnow may impact agriculture by affecting aquaculture. This species harbors a parasite that may infect other fish species and can cause high fish mortality (Bakke et al. 1992). Eurasian minnow populations can adversely impact both recruitment and growth of brown trout. Reduced recruitment and growth rates can reduce the economic value associated with brown trout aquaculture and recreational fishing

nnow may impact agriculture by affecting aquaculture. This species harbors a parasite that may infect other fish species and can cause high fish mortality (Bakke et al. 1992). Eurasian minnow populations can adversely impact both recruitment and growth of brown trout. Reduced recruitment and growth rates can reduce the economic value associated with brown trout aquaculture and recreational fishing.

Factors That Reduce or Remove Injuriousness for Eurasian Minnow

Control

Once introduced, it is difficult and costly to control a Eurasian minnow population (Sandlund 2008). Eradication may be possible from small water bodies in cases where the population is likely to serve as a center for further spread, but no details are given on how to accomplish that (Sandlund 2008). Control may also be possible using habitat modification or biocontrol (introduced predators); however, we know of no published accounts of long-term success by either method. Both control measures of habitat modification and biocontrol cause wildlife or habitat damages and are expensive mitigation strategies, and therefore, are not recommended or considered appropriate under the Injurious Wildlife Evaluation Criteria as a risk management plan for this species.

Potential Ecological Benefits for Introduction

There has been one incidence where the Eurasian minnow was introduced as a biocontrol for the Tune fly (Simuliidae) (Sandlund 2008). However, we do not have information on the success of this introduction. We are not aware of any other documented ecological benefits associated with the Eurasian minnow.

Factors That Contribute to Injuriousness for Prussian Carp

Current Nonnative Occurrences

at Contribute to Injuriousness for Prussian Carp

Current Nonnative Occurrences

This species is not found within the United States. However, it was recently reported to be established in waterways in southern Alberta, Canada, which is the first confirmed record in the wild in North America (Elgin et al. 2014). The Prussian carp has been introduced to many countries of central and Western Europe. This species' current nonnative range includes the Asian countries of Armenia, Turkey, and Uzbekistan and the European countries of Belarus, Belgium, Czech Republic, Denmark, Estonia, France, Germany, Poland, and Switzerland (Britton 2011); it also includes the Iberian Peninsula (Ribeiro et al. 2015).

Potential Introduction and Spread

Potential pathways of introduction include stock enhancement, recreational fishing, and aquaculture. Once introduced, the Prussian carp will naturally disperse to new waterbodies.

The Prussian carp prefers a temperate climate and resides in a variety of freshwater environments, including those with low dissolved oxygen concentrations and increased pollution (Britton 2011). The Prussian carp has an overall high climate match with a Climate 6 ratio of 0.414. This fish species has a high climate match to the Great Lakes region, northern Plains, some western mountain States, and parts of California. The Prussian carp has a medium climate match to much of the United States, including southern Alaska and regions of Hawaii. This species has a low climate match to the southeastern United States, especially Florida and along the Gulf Coast. This species is not found within the United States but has been recently discovered as established in Alberta, Canada (Elgin et al. 2014); the climate match was run prior to this new information, so the results do not include any actual locations in North America

regions of Hawaii. This species has a low climate match to the southeastern United States, especially Florida and along the Gulf Coast. This species is not found within the United States but has been recently discovered as established in Alberta, Canada (Elgin et al. 2014); the climate match was run prior to this new information, so the results do not include any actual locations in North America.

If introduced, the Prussian carp is likely to spread and establish as a consequence of its tolerance to poor quality environments, rapid growth rate, very rare ability to reproduce from unfertilized eggs (gynogenesis), and proven invasiveness outside of the native range.

Potential Impacts to Native Species (Including Threatened and Endangered Species)

The Prussian carp is closely related and behaviorally similar to the crucian carp (Godard and Copp 2012). As with crucian carp, introduced Prussian carp may compete with native fish species, alter freshwater ecosystems, and serve as a vector for parasitic infections. Introduced Prussian carp have been responsible for the decreased biodiversity and overall populations of native fish (including native Cyprinidae), invertebrates, and plants (Anseeuw et al. 2007, Lusk et al. 2010). Thus, if introduced to the United States, the Prussian carp will likely affect numerous native Cyprinid species, including chub, dace, shiner, and minnow fish species (Froese and Pauly 2013). Several of these native Cyprinids, such as the laurel dace ( Chrosomus saylori ) and humpback chub ( Gila cypha ) are listed as endangered or threatened under the Endangered Species Act.

aylori ) and humpback chub ( Gila cypha ) are listed as endangered or threatened under the Endangered Species Act.

Prussian carp can alter freshwater habitats. This was documented in Lake Mikri Prespa (Greece), where scientists correlated increased turbidity with increased numbers of Prussian carp (Crivelli 1995). This carp species increased turbidity levels by disturbing sediment during feeding. These carp also intensively fed on zooplankton, thus resulting in increased phytoplankton abundance and phytoplankton blooms (Crivelli 1995). Increased turbidity results in imbalances in nutrient cycling and ecosystem energetics. If introduced to the United States, Prussian carp could cause increased lake and pond turbidity, increased phytoplankton blooms, imbalances to ecosystem nutrient cycling, and altered freshwater ecosystems.

Several different types of parasitic infections, such as black spot disease (Posthodiplostomatosis) and from Thelohanellus, are associated with the Prussian carp (Ondračková et al. 2002, Markovíc et al. 2012). Black spot disease particularly affects young fish and can cause physical deformations, decreased growth, and decrease in body condition (Ondračková et al. 2002). These parasites and the respective diseases may infect and decrease native fish stocks.

Prussian carp may compete with native fish species and may replace them in the trophic scheme. Large populations of Prussian carp can cause heavy predation on aquatic plants and invertebrates (Anseeuw et al. 2007). Changes in ecosystem cycling and wildlife diversity may have negative effects on the aesthetic, recreational, and economic benefits of the environment.

Potential Impacts to Humans

We have no reports of the Prussian carp being harmful to humans.

Potential Impacts to Agriculture

The Prussian carp may impact agriculture by affecting aquaculture

plants and invertebrates (Anseeuw et al. 2007). Changes in ecosystem cycling and wildlife diversity may have negative effects on the aesthetic, recreational, and economic benefits of the environment.

Potential Impacts to Humans

We have no reports of the Prussian carp being harmful to humans.

Potential Impacts to Agriculture

The Prussian carp may impact agriculture by affecting aquaculture. As mentioned in the Potential Impacts to Native Species section, Prussian carp harbor several types of parasites that may cause physical deformations, decreased growth, and decrease in body condition (Ondračková et al. 2002).

Factors That Reduce or Remove Injuriousness for Prussian Carp

Control

We are not aware of any documented control methods for the Prussian carp. The piscicide rotenone has been used to control the common carp and crucian carp population (Ling 2003) and may be effective against Prussian carp. However, rotenone is not target-specific (Wynne and Masser 2010). Depending on the applied concentration, rotenone kills other aquatic species in the water body. Some fish species are more susceptible than others, and, even if effective against Prussian carp, the use of this piscicide may result in killing native species (Allen et al. 2006). Control measures that would harm other wildlife are not recommended as mitigation to reduce the injurious characteristics of this species and therefore do not meet control measures under the Injurious Wildlife Evaluation Criteria.

Potential Ecological Benefits for Introduction

We are not aware of any documented ecological benefits for the introduction of the Prussian carp.

Factors That Contribute to Injuriousness for Roach

Current Nonnative Occurrences

This species is not found in the United States. The roach has been introduced and become established in England, Ireland, Italy, Madagascar, Morocco, Cyprus, Portugal, the Azores, Spain, and Australia. (Rocabayera and Veiga 2012:Dist. table)

cumented ecological benefits for the introduction of the Prussian carp.

Factors That Contribute to Injuriousness for Roach

Current Nonnative Occurrences

Potential Introduction and Spread

Potential introduction pathways include stocking for recreational fishing and use as bait fish. Once introduced, released, or escaped, the roach naturally disperses to new waterways within the watershed.

This species prefers a temperate climate and can reside in a variety of freshwater habitats (Riehl and Baensch 1991). Hydrologic changes, such as weirs and dams that extend aquatic habitats that are otherwise scarce, enhance the potential spread of the roach (Rocabayera and Veiga 2012). The roach has an overall high climate match to the United States with a Climate 6 ratio of 0.387. Particularly high climate matches occurred in southern and central Alaska, the Great Lakes region, and the western mountain States. The Southeast and Southwest have low climate matches.

If introduced, the roach is likely to spread and establish due to its highly adaptive nature toward habitat and diet choice, high reproductive rate, ability to reproduce with other cyprinid species, long life span, and extraordinary mobility. This species has also proven invasive outside of its native range.

Potential Impacts to Native Species (Including Endangered and Threatened Species)

Potential effects to native species from the introduction of the roach include competition over food and habitat resources, hybridization, altered ecosystem nutrient cycling, and parasite and pathogenic bacteria transmission. The roach is a highly adaptive species and will switch between habitats and food sources to best avoid predation and competition from other species (Winfield and Winfield 1994:385-6)

l effects to native species from the introduction of the roach include competition over food and habitat resources, hybridization, altered ecosystem nutrient cycling, and parasite and pathogenic bacteria transmission. The roach is a highly adaptive species and will switch between habitats and food sources to best avoid predation and competition from other species (Winfield and Winfield 1994:385-6). The roach consumes an omnivorous generalist diet, including benthic invertebrates (especially mollusks), zooplankton, plants, and detritus (Rocabayera and Veiga 2012). With such a varied diet, the roach would likely compete with numerous native fish species from multiple trophic levels. Such species may include shiners, daces, chubs, and stonerollers, several of which are federally listed as endangered or threatened.

Likewise, introduction of the roach would likely detrimentally affect native mollusk species (including mussels and snails), some of which may be federally endangered or threatened. One potentially affected species is the endangered Higgins' eye pearly mussel ( Lampsilis higginsii ), which is native to the upper Mississippi River watershed, where there is high climate match for the roach species. Increased competition with and predation on native species may alter trophic cycling and diversity of native aquatic species.

In Ireland, the roach has hybridized with the rudd ( Scardinius erythrophtalmus ) and the bream ( Abramis brama ). Although the bream is not found in the United States, the rudd is already considered invasive in the Great Lakes (Fuller et al. 1999, Kapuscinski et al. 2012). Hybrids of roaches and rudds could exacerbate the potential adverse effects (competition) of each separate species (Rocabayera and Veiga 2012).

et al. 2012). Hybrids of roaches and rudds could exacerbate the potential adverse effects (competition) of each separate species (Rocabayera and Veiga 2012).

Large populations of the roach may alter nutrient cycling in lake ecosystems. Increased populations of roach may prey heavily on zooplankton, thus resulting in increased phytoplankton communities and algal blooms (Rocabayera and Veiga 2012). These changes alter nutrient cycling and can consequently affect native aquatic species that depend on certain nutrient balances.

Several parasitic infections, including worm cataracts, black spot disease, and tapeworms, have been associated with the roach (Rocabayera and Veiga 2012). The pathogenic bacterium Aeromonas salmonicida also infects the roach, causing furunculosis (Wiklund and Dalsgaard 1998). This disease causes skin ulcers and hemorrhaging. The disease can be spread through a fish's open sore. This disease affects both farmed and wild fish. The causative bacteria A. salmonicida has been isolated from fish in United States freshwaters (USFWS 2011). The roach may spread these parasites and bacteria to new environments and native fish species.

Potential Impacts to Humans

We have no reports of the roach being harmful to humans.

Potential Impacts to Agriculture

The roach may affect agriculture by decreasing aquaculture productivity. Roach can hybridize with other fish species of the subfamily Leuciscinae, including rudd and bream (Pitts et al. 1997, Kottelat and Freyhof 2007). Hybridization can reduce the reproductive success and productivity of the commercial fisheries.

ion can reduce the reproductive success and productivity of the commercial fisheries.

Roaches harbor several parasitic infections (Rocabayera and Veiga 2012) that can impair fish physiology and health. The pathogenic bacterium Aeromonas salmonicida infects the roach, causing furunculosis (Wiklund and Dalsgaard 1998). The disease can be spread through a fish's open sore and can infect farmed fish. Introduction and spread of parasites and pathogenic bacterium to an aquaculture facility can result in increased incidence of fish disease and mortality and decreased productivity and value.

Factors That Reduce or Remove Injuriousness for Roach

Control

An introduced roach population would be difficult to control (Rocabayera and Veiga 2012). Application of the piscicide rotenone may be effective for limited populations of small fish. However, rotenone is not target-specific (Wynne and Masser 2010). Depending on the applied concentration, rotenone kills other aquatic species in the water body. Some fish species are more susceptible than others, and the use of this piscicide may

Potential Ecological Benefits for Introduction

We are not aware of any documented ecological benefits for the introduction of the roach.

Factors That Contribute to Injuriousness for Stone Moroko

Current Nonnative Occurrences

This fish species is not found within the United States. The stone moroko has been introduced and become established throughout Europe and Asia. Within Asia, this fish species is invasive in Afghanistan, Armenia, Iran, Kazakhstan, Laos, Taiwan, Turkey, and Uzbekistan (Copp 2007). In Europe, this fish species' nonnative range includes Albania, Austria, Belgium, Bulgaria, Czech Republic, Denmark, France, Germany, Greece, Hungary, Italy, Lithuania, Moldova, Montenegro, the Netherlands, Poland, Romania, Russia, Serbia, Slovakia, Spain, Sweden, Switzerland, Ukraine, and the United Kingdom (Copp 2007). The stone moroko's nonnative range also includes Algeria and Fiji (Copp 2007)

In Europe, this fish species' nonnative range includes Albania, Austria, Belgium, Bulgaria, Czech Republic, Denmark, France, Germany, Greece, Hungary, Italy, Lithuania, Moldova, Montenegro, the Netherlands, Poland, Romania, Russia, Serbia, Slovakia, Spain, Sweden, Switzerland, Ukraine, and the United Kingdom (Copp 2007). The stone moroko's nonnative range also includes Algeria and Fiji (Copp 2007).

Potential Introduction and Spread

The primary introduction pathways are as unintentional inclusion in the transport water of intentionally stocked fish shipments for both recreational fishing and aquaculture, released or escaped bait, and released or escaped ornamental fish. Once introduced, the stone moroko naturally disperses to new waterways within a watershed. Since the 1960s, this fish has invaded nearly every European country and many Asian countries (Copp et al. 2005).

The stone moroko inhabits a temperate climate (Baensch and Riehl 1993) and a variety of freshwater habitats, including those with poor dissolved oxygen concentrations (Copp 2007). The stone moroko has an overall high climate match with a Climate 6 ratio of 0.557. This species has a high or medium climate match to most of the United States. The highest matches are in the Southeast, Great Lakes, central plains, and West Coast.

If introduced, the stone moroko is highly likely to spread and establish. This fish species is a habitat generalist, diet generalist, quick growing, highly adaptable to new environments, and highly mobile. Additionally, the stone moroko has proven invasive outside of its native range (Copp 2007, Kottelat and Freyhof 2007, Witkowski 2011).

Potential Impacts to Native Species (Including Endangered and Threatened Species)

In much of the stone moroko's nonnative range, the introduction of this species has been linked to the decline of native freshwater fish species (Copp 2007)

ts, and highly mobile. Additionally, the stone moroko has proven invasive outside of its native range (Copp 2007, Kottelat and Freyhof 2007, Witkowski 2011).

Potential Impacts to Native Species (Including Endangered and Threatened Species)

In much of the stone moroko's nonnative range, the introduction of this species has been linked to the decline of native freshwater fish species (Copp 2007). The stone moroko could potentially adversely affect native species through predation, competition, disease transmission, and altering freshwater ecosystems (Witkowski 2011).

Stone moroko introductions have mostly originated from unintentional inclusion in the transport water of intentionally stocked fish species. In many stocked ponds, the stone moroko actually outcompetes the farmed fish species for food resources, which results in decreased production of the farmed fish (Witkowski 2011). The stone moroko's omnivorous diet includes insects, fish, fish eggs, molluscs, planktonic crustaceans, algae (Froese and Pauly 2014), and plants (Kottelat and Freyhof 2007). With this diet, the stone moroko would compete with many native U.S. freshwater fish, including minnow, dace, sunfish, and darter species.

In the United Kingdom, Italy, China, and Russia, the introduction of the stone moroko correlates with dramatic declines in native fish populations and species diversity (Copp 2007). The stone moroko first competes with native fish for food resources and then predates on the eggs, larvae, and juveniles of these same native fish species (Pinder 2005, Britton et al. 2007).

ies (Pinder 2005, Britton et al. 2007).

The stone moroko is a vector of the pathogenic, rosette-like agent Sphaerothecum destruens (Gozlan et al. 2005, Pinder et al. 2005), which is a documented pathogen of farmed and wild European fish. The stone moroko is a healthy host for this deadly, nonspecific pathogen that could threaten aquaculture trade, including that of salmonids (Gozlan et al. 2009). This pathogen infects a fish's internal organs causing spawning failure, organ failure, and death (Gozlan et al. 2005). This pathogen has been documented as infecting the sunbleak ( Leucaspius delineatus ), which are native to eastern Europe, and Chinook salmon ( Oncorhynchus tshawytscha ), Atlantic salmon, and the fathead minnow ( Pimephales promelas ), which are native to the United States (Gozlan et al. 2005).

The stone moroko consumes large quantities of zooplankton. The declines in zooplankton population results in increased phytoplankton populations, which in turn causes algal blooms and unnaturally high nutrient loads (eutrophication). These changes can cause imbalanced nutrient cycling, decrease dissolved oxygen concentrations, and adversely impact the health of native aquatic species.

Potential Impacts to Humans

We have no reports of the stone moroko being harmful to humans.

Potential Impacts to Agriculture

The stone moroko may affect agriculture by decreasing aquaculture productivity. This species often contaminates farmed fish stocks and competes with the farmed species for food resources, resulting in decreased aquaculture productivity (Witkowski 2011). The stone moroko is an unaffected carrier of the pathogenic, rosette-like agent Sphaerothecum destruens (Gozlan et al. 2005, Pinder et al. 2005). This pathogen is transmitted through water and causes reproductive failure, disease, and death to farmed fish. This pathogen is not species-specific and has been known to infect cyprinid and salmonid fish species

quaculture productivity (Witkowski 2011). The stone moroko is an unaffected carrier of the pathogenic, rosette-like agent Sphaerothecum destruens (Gozlan et al. 2005, Pinder et al. 2005). This pathogen is transmitted through water and causes reproductive failure, disease, and death to farmed fish. This pathogen is not species-specific and has been known to infect cyprinid and salmonid fish species. Sphaerothecum destruens is responsible for disease outbreaks in North American salmonids and causes mortality in both juvenile and adult fish (Gozlan et al. 2009). If this pathogen was introduced to an aquaculture facility, it is likely to spread and infect numerous fish, resulting in high mortality. Further research is needed to ascertain this pathogen's prevalence in the wild environment (Gozlan et al. 2009).

Factors That Reduce or Remove Injuriousness for Stone Moroko

Control

An established, invasive stone moroko population would be both difficult and costly to control (Copp 2007). Additionally, this fish species has a higher tolerance for the piscicide rotenone than most other fish belonging to the cyprinid group (Allen et al. 2006). Applications of rotenone for stone moroko control is likely to adversely impact native aquatic fish species. Control measures that would harm other wildlife are not recommended as mitigation to reduce the injurious characteristics of this species and therefore do not meet control measures under the Injurious Wildlife Evaluation Criteria.

Potential Ecological Benefits for Introduction

We are not aware of any documented ecological benefits for the introduction of the stone moroko.

Factors That Contribute to Injuriousness for Nile Perch

Current Nonnative Occurrences

This species is not currently found within the United States. The Nile perch is invasive in the Kenyan, Tanzanian, and Ugandan watersheds of Lake Victoria and Lake Kyoga (Africa). This species has also been introduced to Cuba (Welcomme 1988)

nted ecological benefits for the introduction of the stone moroko.

Factors That Contribute to Injuriousness for Nile Perch

Current Nonnative Occurrences

Potential Introduction and Spread

This species was stocked in Texas reservoirs, although this population failed to establish (Fuller et al. 1999, Howells 2001). However, with continued release events, we anticipate that the Nile perch is likely to establish. Likely introduction pathways include use for aquaculture and recreational fishing. Over the past 60 years, the Nile perch has invaded, established, and become the dominant fish species within this species' nonnative African range (Witte 2013).

The Nile perch prefers a tropical climate and can inhabit a variety of freshwater and brackish habitats (Witte 2013). The Nile perch has an overall medium climate match with a Climate 6 ratio of 0.038. Of the 11 species in this rule, the Nile perch has the only overall medium climate match to the United States. However, this fish species has a high climate match to the Southeast (Florida and Gulf Coast), Southwest (California), Hawaii, Puerto Rico, and the U.S. Virgin Islands.

If introduced into the United States, the Nile perch is likely to spread and establish due to this species' nature as a habitat generalist and generalist predator, long life span, quick growth rate, high reproductive rate, extraordinary mobility, and proven invasiveness outside of the species' native range (Witte 2013, Asila and Ogari 1988, Ribbinick 1982).

Potential Impacts to Native Species (Including Endangered and Threatened Species)

Potential impacts of introduction of the Nile perch include outcompeting and preying on native species, altering habitats and trophic systems, and disrupting ecosystem nutrient cycling

dinary mobility, and proven invasiveness outside of the species' native range (Witte 2013, Asila and Ogari 1988, Ribbinick 1982).

Potential Impacts to Native Species (Including Endangered and Threatened Species)

Potential impacts of introduction of the Nile perch include outcompeting and preying on native species, altering habitats and trophic systems, and disrupting ecosystem nutrient cycling. The Nile perch can produce up to 15 million eggs per breeding cycle (Asila and Ogari 1988), likely contributing to this species' efficiency and effectiveness in establishing an introduced population.

Historical evidence from the Lake Victoria (Africa) basin indicate that the Nile perch outcompeted and preyed on at least 200 species endemic fish species, leading to their extinction (Kaufman 1992, Snoeks 2010, Witte 2013). Many of the affected species were haplochromine cichlid fish species, and the populations of native lung fish ( Protopterus aethiopicus ) and catfish species ( Bagrus docmak, Xenoclarias eupogon, Synodontis victoria ) also witnessed serious declines (Witte 2013). By the late 1980s, only three fish species, including the cyprinid Rastrineobolas argentea and the introduced Nile perch and Nile tilapia ( Oreochromis niloticus ) were common in Lake Victoria (Witte 2013).

The haplochromine cichlid species comprised 15 subtrophic groups with varied food (detritus, phytoplankton, algae, plants, mollusks, zooplankton, insects, prawns, crabs, fish, and parasites) and habitat preferences (Witte and Van Oijen 1990, Van Oijen 1996). The depletion of so many fish species has drastically altered the Lake Victoria ecosystem's trophic level structure and biodiversity. These changes resulted in abnormally high lake eutrophication and frequency of algal blooms (Witte 2013).

The depletion of the native fish species in Lake Victoria by Nile perch led to the loss of income and food for local villagers. Nile perch are not a suitable replacement for traditional fishing

es has drastically altered the Lake Victoria ecosystem's trophic level structure and biodiversity. These changes res

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