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Blue catfish

Ictalurus furcatus

Image courtesy of Duane Raver / U.S. Fish and Wildlife Service

Maryland, Virginia

Fyke Net, Gillnet, Pound Net, Seine Net, Trap

August 10, 2015

Rachel Simon, Independent Research Analyst

Disclaimer: Seafood Watch® strives to have all Seafood Reports reviewed for accuracy and completeness by external scientists with expertise in ecology, fisheries science and aquaculture. Scientific review, however, does not constitute an endorsement of the Seafood Watch® program or its recommendations on the part of the reviewing scientists. Seafood Watch® is solely responsible for the conclusions reached in this report.

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About Seafood Watch® Monterey Bay Aquarium’s Seafood Watch® program evaluates the ecological sustainability of wild-caught and farmed seafood commonly found in the United States marketplace. Seafood Watch® defines sustainable seafood as originating from sources, whether wild-caught or farmed, which can maintain or increase production in the long-term without jeopardizing the structure or function of affected ecosystems. Seafood Watch® makes its science-based recommendations available to the public in the form of regional pocket guides that can be downloaded from www.seafoodwatch.org. The program’s goals are to raise awareness of important ocean conservation issues and empower seafood consumers and businesses to make choices for healthy oceans. Each sustainability recommendation on the regional pocket guides is supported by a Seafood Report. Each report synthesizes and analyzes the most current ecological, fisheries and ecosystem science on a species, then evaluates this information against the program’s conservation ethic to arrive at a recommendation of “Best Choices,” “Good Alternatives” or “Avoid.” The detailed evaluation methodology is available upon request. In producing the Seafood Reports, Seafood Watch® seeks out research published in academic, peer-reviewed journals whenever possible. Other sources of information include government technical publications, fishery management plans and supporting documents, and other scientific reviews of ecological sustainability. Seafood Watch® Research Analysts also communicate regularly with ecologists, fisheries and aquaculture scientists, and members of industry and conservation organizations when evaluating fisheries and aquaculture practices. Capture fisheries and aquaculture practices are highly dynamic; as the scientific information on each species changes, Seafood Watch’s sustainability recommendations and the underlying Seafood Reports will be updated to reflect these changes. Parties interested in capture fisheries, aquaculture practices and the sustainability of ocean ecosystems are welcome to use Seafood Reports in any way they find useful. For more information about Seafood Watch® and Seafood Reports, please contact the Seafood Watch® program at Monterey Bay Aquarium by calling 1-877-229-9990.

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Guiding Principles Seafood Watch defines sustainable seafood as originating from sources, whether fished1 or farmed, that can maintain or increase production in the long-term without jeopardizing the structure or function of affected ecosystems. Based on this principle, Seafood Watch had developed four sustainability criteria for evaluating wild-catch fisheries for consumers and businesses. These criteria are:

• How does fishing affect the species under assessment? • How does the fishing affect other, target and non-target species? • How effective is the fishery’s management? • How does the fishing affect habitats and the stability of the ecosystem?

Each criterion includes:

• Factors to evaluate and score • Guidelines for integrating these factors to produce a numerical score and rating

Once a rating has been assigned to each criterion, we develop an overall recommendation. Criteria ratings and the overall recommendation are color coded to correspond to the categories on the Seafood Watch pocket guide and the Safina Center’s online guide: Best Choice/Green: Are well managed and caught in ways that cause little harm to habitats or other wildlife. Good Alternative/Yellow: Buy, but be aware there are concerns with how they’re caught. Avoid/Red: Take a pass on these for now. These items are overfished or caught in ways that harm other marine life or the environment.

1 “Fish” is used throughout this document to refer to finfish, shellfish and other invertebrates.

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Summary This report includes recommendations for Blue catfish (Ictalurus furcatus), caught by fyke net, gillnet, pound net, seine net, and trap net (also known as hoop net). The fishery occurs in several rivers of the Chesapeake Bay region in Maryland and Virginia.

Blue catfish have medium inherent vulnerability to fishing pressure. They grow quickly and can reach a maximum size of 165 cm and live for 21 years or more. Blue catfish are sexually mature around 50 cm and females are relatively fecund, producing 4,000 to 8,000 eggs per kilogram of body weight, which are laid in an isolated nest with suitable cover. There is low conservation concern, as blue catfish are an invasive species in the Chesapeake Bay area and are detrimentally affecting native species through predation and resource competition. As a result, managers are focusing on ways to reduce and prevent further spread of the blue catfish population.

Bycatch rates for finfish and invertebrates are low for the blue catfish fishery, which is under development and is currently comprised of a mix of directed and non-directed fisheries with little public information on how much blue catfish comes from each. Blue catfish fisheries have been reported to incidentally capture Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and shortnose sturgeon (Acipenser brevirostrum), both of which are endangered (St. Pierre 2006)(NOAA Fisheries 2014). Diamondback terrapins (Malaclemys terrapin) (Fratto et al. 2008) are also thought to be an occasional bycatch species. Alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis) (collectively referred to as river herring), and American shad (Alosa sapidissima) are also caught in pound net and gillnet fisheries in the Chesapeake Bay. These species are highly depleted relative to historic levels (ASMFC 2007, ASMFC 2012b) and so are included here as species of concern. Landings made with trap nets in Virginia (the biggest single fishery for blue catfish in terms of landings in either state (NOAA pers. comm.)) may be directed to blue catfish fisheries or they may be fisheries targeting croaker (Micropogonias undulatus) or Spot (Leiostomus xanthurus) (Joe Grist, pers. comm.).There is no information on discard and mortality rates for the blue catfish fishery, but overall, it appears that discard rates of blue catfish bycatch are low compared to other fisheries.

There is currently no bay-wide management plan for blue catfish, but one is in the process of being developed and the stated intent is to mitigate the spread and minimize the impacts of invasive catfish species on the Chesapeake Bay ecosystem. There are some regulations in place for blue catfish fisheries, specifically on amounts and sizes of catfish caught per day due to concern of PCBs and other harmful compounds that can bioaccumulate in larger fish. In addition to these regulations, it is illegal in Maryland, Virginia, and Delaware to transport and release live blue catfish.

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Blue catfish are fished with fyke nets, gillnets, pound nets, seine nets, and trap nets, depending on season, conditions and waterman preference. These gear types tend to have a low impact on benthic habitats. Specifically, there is no direct information to determine if any adverse effects on essential fish habitat are occurring in the blue catfish fishery. Finally, blue catfish are both competitors with and apex predators on ecologically important species, and constitute a major prey item for certain predatory birds (likely contributing to their bioaccumulation of PCBs), hence their reduction or removal from the Chesapeake Bay ecosystem will likely greatly benefit the native species.

Table of Conservation Concerns and Overall Recommendations

Stock / Fishery Impacts on the Stock

Impacts on other Spp.

Management Habitat and Ecosystem

Overall Recommendation

Blue Catfish United States Chesapeake Bay–Gillnet, Bottom

Green (5.00) Yellow (2.24)

Yellow (3.00) Green (3.87) Best Choice (3.376)

Blue Catfish United States Chesapeake Bay–Pound Net



Blue Catfish United States Chesapeake Bay–Fyke Net



Blue Catfish United States Chesapeake Bay–Seine Net, Beach



Blue Catfish United States Chesapeake Bay–Trap Net



Scoring Guide Scores range from zero to five where zero indicates very poor performance and five indicates the fishing operations have no significant impact. Final Score = geometric mean of the four Scores (Criterion 1, Criterion 2, Criterion 3, Criterion 4). • Best Choice/Green = Final Score >3.2, and no Red Criteria, and no Critical scores

• Good Alternative/Yellow = Final score >2.2-3.2, and neither Harvest Strategy (Factor 3.1)

nor Bycatch Management Strategy (Factor 3.2) are Very High Concern2, and no more than one Red Criterion, and no Critical scores

2 Because effective management is an essential component of sustainable fisheries, Seafood Watch issues an Avoid recommendation for any fishery scored as a Very High Concern for either factor under Management (Criterion 3).

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• Avoid/Red = Final Score <=2.2, or either Harvest Strategy (Factor 3.1) or Bycatch Management Strategy (Factor 3.2) is Very High Concern or two or more Red Criteria, or one or more Critical scores.

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Table of Contents About Seafood Watch® ................................................................................................................................. 2

Guiding Principles ......................................................................................................................................... 3

Summary ....................................................................................................................................................... 4

Assessment ................................................................................................................................................. 13

Criterion 1: Stock for which you want a recommendation ..................................................................... 13

Criterion 2: Impacts on Other Species .................................................................................................... 19

Criterion 3: Management effectiveness ................................................................................................. 37

Criterion 4: Impacts on the habitat and ecosystem................................................................................ 48

Acknowledgements ..................................................................................................................................... 54

References .................................................................................................................................................. 55

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Introduction

Scope of the Analysis and Ensuing Recommendation

This report includes recommendations for blue catfish (Ictalurus furcatus), caught by fyke net, gillnet, pound net, seine net, and trap nets. The fishery occurs in several rivers of the Chesapeake Bay region in Maryland and Virginia.

Overview of the Species and Management Bodies

Blue catfish, Ictalurus furcatus, are the largest species of North American catfish, living up to 20 years (Graham 1999) and reaching 5.5 ft in length and over 100 lbs in weight (CBP 2012a). They are bottom-dwellers, preferring large rivers with deep channels, swift currents and sandy bottoms, and are found primarily in freshwater, but have a high tolerance for different habitat and water conditions (Garman et al. 2013). Blue catfish attain sexual maturity between 4 and 7 years of age, with females producing 40,000 to 50,000 eggs per year, and spawning between late May and June, often in lower-salinity streams and smaller tributaries (MDN 2007)(DGIF 2015). They are the most migratory of all catfish species and are capable of moving sizeable distances in search of preferred spawning habitats (Graham 1999). Blue catfish are opportunistic and generalist predators and therefore have a varied diet of fish, small crustaceans, worms, clams, mussels, crabs, insects, and plant matter (Brown and Dendy 1961)(Minckley 1962)(Perry 1969)(Fabrizio et al. 2010)(Ogburn 2014)(Orth and Schmitt 2014)(Garman et al. 2013). They are native to Ohio, Missouri, and Mississippi river basins, but have been introduced into other areas, including several rivers in the Chesapeake Bay region, where they occur in both fresh and brackish waters (Fabrizio et al. 2010).

In the 1970s and ‘80s, blue catfish were introduced into the James, Rappahannock, and York Rivers in Virginia for recreational purposes (Jenkins and Burkhead 1994)(Edmonds 2003)(Schloesser et al. 2011). Since then, they have greatly expanded their range into all coastal rivers in Virginia (Jenkins and Burkhead 1994)(Schloesser et al. 2011), several rivers in Maryland, such as the Potomac, Patuxent, Elk, Choptank, Nanticoke, and Sassafras, and can be found as far north in the Chesapeake Bay as the Susquehanna River in waters of up to 14 ppt (MDNR 2007)(Schloesser et al. 2011)(SERC 2014).

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Figure 1. Blue catfish distribution (blue circles) in the Chesapeake Bay region and presence of blue catfish in the 12th order watershed (solid polygons) as of June 1, 2013 (from Garman et al. 2013).

Blue catfish are both commercially and recreationally fished in the Chesapeake Bay region. In the 1990s, a fishery management plan for blue catfish in the Chesapeake Bay was considered, however, at that time, the fisheries appeared to be healthy and there was a lack of species-specific data, so no plan was implemented (MDNR 2011). Since the early 2000s, blue catfish commercial catches have been steadily increasing to 308,000 lbs in Maryland and 1,300,000 lbs in Virginia. Recreational catches of blue catfish in Maryland are limited, but seem to be dramatically increasing, especially over the last two years (2013—20,000 lbs; 2014—56,000 lbs) (NMFS 2015). Virginia, which supports a substantial trophy fishery that generates millions of dollars for their economy, reported 99,600 lbs in 2013 and 301,300 lbs in 2014. A small percentage of annual blue catfish landings are bycatch from other gillnet fisheries in the Potomac, and likely the James Rivers (Fabrizio 2011), as well as from the blue crab pot fishery (Havens et al. 2008)(CCRM 2010). In these fisheries, blue catfish often reduce gear efficiency for target species due to their high abundances (Fabrizio 2011). In 2012, blue catfish were deemed invasive in the Chesapeake Bay region because of their potential to negatively impact native species and the ecology of the bay (CBP 2012c). In Maryland, the Department of Natural Resources Fisheries Service, is responsible for

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managing commercial and recreational fishing, and in Virginia, the Virginia Marine Resources Commission (VMRC) has jurisdiction over commercial fisheries, which include the harvest of catfish from tidal waters (MDNR 2012a)(Bob Greenlee, pers.comm.). Fisheries in the Potomac River are regulated by the Potomac River Fisheries Commission (PRFC 2015). There is no formal management plan for the blue catfish fishery, but in 2012 the Chesapeake Bay Program’s Sustainable Fisheries Goal Implementation Team (GIT) adopted an ‘invasive catfish policy statement,’ which outlines the need to control the effects of these invasive fish (CBP 2012c). The GIT's Invasive Catfish Task Force has been appointed the task of exploring potential management measures and proposing actions to mitigate the likely negative impacts of invasive catfish. Research efforts are currently underway and will contribute to the gaps in blue catfish life history, population sizes, movement, and gear efficacy. Fish contaminant levels will be considered during the development of a management plan (Hale et al. 2012).

Production Statistics

The United States is the sole producer of wild-caught blue catfish. In 2013, total landings of blue catfish reached 3,265,884 lbs, with the majority (65%) landed in Lousiana, followed by Virginia (27%), Maryland (6%), Texas (2%), North Carolina (0.1%) and Alabama (0.001%) (NOAA 2014).

Figure 2. Commercial blue catfish production. Percent reflects relative contribution to landings by weight in 2013 (data source: NOAA 2014).

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Over the course of the last 10 years, landings have fluctuated the most in Louisiana, but in Texas, Maryland, and Virginia, landings were steadily increasing until a decline in 2013.

Figure 3. Annual blue catfish commercial landings from 2003-2013 (data from: NOAA 2014).

Between 2012 and 2014, Virginia commercial catfish harvest (unclassified and blue catfish) has varied, but Potomac River commercial catfish harvest of unclassified and blue catfish has steadily increased since 2011.

Table 1. Pounds of Virginia commercial catfish, unclassified and blue catfish harvest by year, 2010 through 2014 (data from Racheael Maulorico, VMRC).

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Table 2. Pounds of Potomac River commercial catfish, unclassified and blue catfish harvest by year, 2010 through 2014.

Importance to the US/North American Market

Between 2000 and 2013, blue catfish landings in Louisiana have ranged from 2 million to 4 million pounds, with a market value averaging more than $1.4 million in 2013. In Maryland, between 2003 and 2013, commercial catches of blue catfish ranged from 734 to 308,000 lbs (NMFS 2015), with fishing mostly occurring in the Potomac River (Groves et al. 2012). In Virginia, commercial catches of blue catfish are significantly higher, ranging from a mere 21,000 lbs in 2003, and steadily increasing to over 2 million lbs in 2012 (NMFS 2015) and back down to 1,300,000 lbs in 2013. However, these reported catches do not include the hundreds of metric tons of “unclassified catfish” (~2 million lbs) that are landed each year in these states (VMRC 2010a) where blue catfish are likely the dominant species due to relative abundance.

At present, there is low market demand and human consumption concerns associated with accumulation of contaminants (like PCBs) in blue catfish (Schloesser et al. 2011).

Common and Market Names

Blue catfish are also known as silver cat, hump-back blue, bullhead, Mississippi cat, forktail cat, chucklehead cat, and blue channel catfish.

Primary Product Forms

Blue catfish are sold in both live and dead markets, fresh and frozen as whole fillets, trimmed fillets, fillet strips, steaks, and nuggets.

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Assessment This section assesses the sustainability of the fishery(s) relative to the Seafood Watch Criteria for Fisheries, available at http://www.seafoodwatch.org.

Criterion 1: Stock for which you want a recommendation This criterion evaluates the impact of fishing mortality on the species, given its current abundance. The inherent vulnerability to fishing rating influences how abundance is scored, when abundance is unknown. The final Criterion 1 score is determined by taking the geometric mean of the abundance and fishing mortality scores. The Criterion 1 rating is determined as follows:

• Score >3.2=Green or Low Concern • Score >2.2 and <=3.2=Yellow or Moderate Concern • Score <=2.2=Red or High Concern

Rating is Critical if Factor 1.3 (Fishing Mortality) is Critical.

Criterion 1 Summary

BLUE CATFISH Region / Method Inherent

Vulnerability Stock Status Fishing

Mortality Subscore

United States Chesapeake Bay Fyke Net

2.00:Medium 5.00:Very Low Concern

5.00:Very Low Concern

Green (5.000)

United States Chesapeake Bay Gillnet, Bottom



Green (5.000)

United States Chesapeake Bay Pound Net



Green (5.000)

United States Chesapeake Bay Seine Net, Beach



Green (5.000)

United States Chesapeake Bay Trap Net



Green (5.000)

Criterion 1 Assessment

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BLUE CATFISH

Factor 1.1–Inherent Vulnerability

Scoring Guidelines

• Low—The FishBase vulnerability score for species is 0-35, OR species exhibits life-history characteristics that make it resilient to fishing, (e.g., early maturing).

• Medium—The FishBase vulnerability score for species is 36-55, OR species exhibits life-history characteristics that make it neither particularly vulnerable nor resilient to fishing, (e.g., moderate age at sexual maturity (5-15 years), moderate maximum age (10-25 years), moderate maximum size, and middle of food chain).

• High—The FishBase vulnerability score for species is 56-100, OR species exhibits life-history characteristics that make is particularly vulnerable to fishing, (e.g., long-lived (>25 years), late maturing (>15 years), low reproduction rate, large body size, and top-predator). Note: The FishBase vulnerability scores is an index of the inherent vulnerability of marine fishes to fishing based on life-history parameters: maximum length, age at first maturity, longevity, growth rate, natural mortality rate, fecundity, spatial behaviors (e.g., schooling, aggregating for breeding, or consistently returning to the same sites for feeding or reproduction) and geographic range.

United States Chesapeake Bay, Fyke Net

United States Chesapeake Bay, Gillnet, Bottom

United States Chesapeake Bay, Pound Net

United States Chesapeake Bay, Seine Net, Beach

United States Chesapeake Bay, Trap Net

Medium

The FishBase score for blue catfish is 85, which is considered high vulnerability (Froese and Pauly 2014), but using the productivity analysis tool in the Seafood Watch criteria, blue catfish have medium inherent vulnerability, with a score of 1.83, due to their moderate age at sexual maturity, their reproductive strategy and their moderate lifespan (see Table 3).

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Rationale

Table 3. Life-history characteristics for blue catfish

Factor 1.2–Stock Status

Scoring Guidelines

• 5 (Very Low Concern)—Strong evidence exists that the population is above target abundance level (e.g., biomass at maximum sustainable yield, BMSY) or near virgin biomass.

• 4 (Low Concern)—Population may be below target abundance level, but it is considered not overfished.

• 3 (Moderate Concern) —Abundance level is unknown and the species has a low or medium inherent vulnerability to fishing.

• 2 (High Concern)—Population is overfished, depleted, or a species of concern, OR abundance is unknown and the species has a high inherent vulnerability to fishing.

• 1 (Very High Concern)—Population is listed as threatened or endangered.

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Very Low Concern

Blue catfish are an invasive species in the Chesapeake Bay (CBP 2012c). All non-natives are rated very low concern for stock status regardless of their abundance. Rationale A formal population assessment for blue catfish has not been conducted in the Chesapeake Bay region, so there is no metric for abundance. However, blue catfish are considered an invasive species in the Chesapeake Bay region. Blue catfish are native to the Mississippi, Missouri, and Ohio River basins, but were introduced into the James, Rappahannock, and York rivers in Virginia during the 1970s and 1980s to establish new recreational fisheries in Virginia (ICTF 2014). They have rapidly spread throughout the Chesapeake Bay region into nearly every major tributary. Due to their expanding range and rapidly increasing populations, fishery managers are concerned that the negative impacts blue catfish may have on native species and the ecology of the bay will be irreversible if not addressed soon (CWG 2012)(ASMFC 2012)(TBN 2012)(ICTF 2014). The Invasive Catfish Taskforce developed recommendations addressing the following four objectives: 1) slowing and reducing the spread of invasive catfishes populations into currently uninhabited water by designing and implementing targeted fishery-independent removals of invasive catfish in places of significant ecological value, 2) minimizing the ecological impacts of invasive catfishes on native species by establishing monitoring programs dedicated to identifying and tracking invasive catfish distributions and population status, incentivizing increased harvests of invasive catfishes by small boat operations, and exploring the use of electrofishing for commercial harvest purposes, 3) promoting a large-scale fishery to significantly reduce blue catfish abundance while providing economic benefits to the region, and 4) increasing outreach and education to improve public awareness that blue catfish pose a risk to native species and to continue to lessen the probability of unauthorized introductions into other water bodies in the bay watershed (ICTF 2014). However, it is important to note that establishing a new blue catfish fishery could potentially increase blue catfish population growth through increased recruitment, growth rate and reduction of natural mortality (Ricker 1975)(Pasko and Goldberg 2014), thereby dampening the fishery's intended effect (Bilkovic et al. 2014). Blue catfish support both commercial and recreational fisheries in the Chesapeake Bay region. There are no population assessments for blue catfish in Maryland and Virginia, however there is evidence from surveys and catch records that blue catfish abundance is high and increasing since their introduction in

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the 1970s/1980s, partially due to range expansion beyond their usual salinity tolerance (Greenlee 2010)(Fabrizio et al. 2010b)(Schloesser et al. 2011)(Tuckey and Fabrizio 2011)(Groves and Love 2011)(MDNR 2013). For example, population surveys conducted in the Potomac River (Maryland) suggest that blue catfish abundance has significantly increased since the early 2000s and, in some portions of the rivers, represents up to 75% of total fish biomass (Schloesser et al. 2011)(Groves and Love 2011). In the James, Rappahannock, and York rivers (Virginia), blue catfish density was estimated through electrofishing to be extremely high, ranging from 223 to 6,106 fish/hour (Greenlee 2010). In the James and Rappahannock rivers specifically, blue catfish density increased substantially between 2000 and 2008, with catch per unit effort (CPUE) reaching 4,449 fish/hr and 6,106 fish/hr, respectively (Greenlee 2010). These catch rates are an order of magnitude higher than those reported for any other catfish species (Fabrizio et al. 2010b). Additionally, trawl surveys conducted in some Virginia rivers indicate that abundance of juvenile and adult blue catfish has increased in recent years (Schloesser et al. 2011)(Tuckey and Fabrizio 2011). The success of blue catfish in expanding their range into other Chesapeake Bay rivers can be due to a number of reasons. It may be a result of illegal movement of fish among rivers (TBN 2012), the removal of dams or introduction of fish passages in some rivers (Fabrizio et al. 2010a), as well as the ability of blue catfish to tolerate rivers with higher salinities (Perry 1969)(Fabrizio et al. 2010)(Fabrizio et al. 2010a). Natural movement among rivers is also likely to be an important cause of range expansion, especially during periods of high freshwater flow, when salinities at river mouths are reduced. Movement of blue catfish from primarily tidal freshwater regions (average annual salinity <0.5 practical salinity units [psu]) into oligohaline (0.5–5 psu) and mesohaline (5–18 psu) waters of Chesapeake Bay tributaries occurred following a 10-15 year lag after their introduction into the James and Rappahannock rivers beginning in 1974 (Dennison et al. 1993)(Schloesser et al. 2011). Blue catfish can tolerate salinities of 14 parts per thousand (ppt) or higher and can therefore move into estuarine reaches of tidal tributaries (Schloesser et al. 2011).

Factor 1.3–Fishing Mortality

Scoring Guidelines

• 5 (Very Low Concern)—Highly likely that fishing mortality is below a sustainable level (e.g., below fishing mortality at maximum sustainable yield, FMSY), OR fishery does not target species and its contribution to the mortality of species is negligible (≤ 5% of a sustainable level of fishing mortality).

• 3.67 (Low Concern)—Probable (>50%) chance that fishing mortality is at or below a sustainable level, but some uncertainty exists, OR fishery does not target species and does not adversely affect species, but its contribution to mortality is not negligible, OR fishing mortality is unknown, but the population is healthy and the species has a low susceptibility to the fishery (low chance of being caught).

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• 2.33 (Moderate Concern)—Fishing mortality is fluctuating around sustainable levels, OR fishing mortality is unknown and species has a moderate-high susceptibility to the fishery and, if species is depleted, reasonable management is in place.

• 1 (High Concern)—Overfishing is occurring, but management is in place to curtail overfishing, OR fishing mortality is unknown, species is depleted, and no management is in place.

• 0 (Critical)—Overfishing is known to be occurring and no reasonable management is in place to curtail overfishing.






Very Low Concern

Blue catfish are an invasive species in the Chesapeake Bay (CBP 2012c). All non-natives are rated very low concern for stock status regardless of their fishing mortality. Rationale A formal stock assessment for blue catfish has not been conducted in the Chesapeake Bay region, so there is no metric for fishing mortality. However, blue catfish are invasive in the Chesapeake Bay, therefore bay region and fishery managers want to reduce their abundance.

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Criterion 2: Impacts on Other Species All main retained and bycatch species in the fishery are evaluated in the same way as the species under assessment were evaluated in Criterion 1. Seafood Watch® defines bycatch as all fisheries-related mortality or injury to species other than the retained catch. Examples include discards, endangered or threatened species catch, and ghostfishing. To determine the final Criterion 2 score, the score for the lowest scoring retained/bycatch species is multiplied by the discard rate score (ranges from 0-1), which evaluates the amount of non-retained catch (discards) and bait use relative to the retained catch. The Criterion 2 rating is determined as follows:


Rating is Critical if Factor 2.3 (Fishing Mortality) is Critical.

Criterion 2 Summary

Blue Catfish: United States Chesapeake Bay, Fyke Net

Subscore: 2.236 Discard Rate: 1.00 C2 Rate: 2.236

Species Inherent Vulnerability

Stock Status Fishing Mortality

Subscore

ATLANTIC STURGEON High 1.00: Very High Concern

5.00: Very Low Concern

2.236

SHORTNOSE STURGEON High 1.00: Very High Concern


2.236

DIAMONDBACK TERRAPINS (UNSPECIFIED)

High 2.00: High Concern

3.67: Low Concern

2.709

BLUE CATFISH Medium 5.00: Very Low Concern


5.000

Blue Catfish: United States Chesapeake Bay, Gillnet, Bottom




Subscore



2.236



2.236

AMERICAN SHAD Medium 2.00: High Concern

3.67: Low Concern

2.709

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3.67: Low Concern

2.709

RIVER HERRING Medium 2.00: High Concern

3.67: Low Concern

2.709



5.000

Blue Catfish: United States Chesapeake Bay, Pound Net




Subscore



2.236



2.236



3.67: Low Concern

2.709

RIVER HERRING Medium 2.00: High Concern

3.67: Low Concern

2.709



5.000

Blue Catfish: United States Chesapeake Bay, Seine Net, Beach




Subscore



2.236



2.236



5.000

Blue Catfish: United States Chesapeake Bay, Trap Net




Subscore



2.236



2.236

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5.000

Blue catfish in the Chesapeake Bay region are commercially caught with a variety of gears, including trap nets, fyke nets, bottom gillnets, haul seines and pound nets. At first, these fisheries caught mainly blue catfish as bycatch when targeting other, more valuable species. More recently, the value of blue catfish has increased, leading to the species being more directly targeted. As such, the ‘fishery’ for blue catfish is one in development, and is currently comprised of a mix of directed and non-directed fisheries with little public information on how much blue catfish comes from each. For this reason, the list of species identified here may not be a good reflection of the species actually caught with blue catfish at this time. The list has been determined from the literature (much of which is old), from communication with fishery managers in the Chesapeake Bay, and from limited observer and logbook data made available for this assessment (Appendix 1 and Appendix 2). As with all Seafood Watch reports, this report will be updated to reflect any robust evidence or scientific expert opinion presented to us on the catch composition of fisheries that catch blue catfish.

Blue catfish fisheries have been reported to incidentally capture Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and shortnose sturgeon (Acipenser brevirostrum), both of which are endangered (St. Pierre 2006)(NOAA Fisheries 2014). Diamondback terrapins (Malaclemys terrapin) (Fratto et al. 2008), Kemp's ridley turtles (Lepidochelys kempii) and loggerhead turtles (Caretta caretta) are also an occasional bycatch species in pound nets in the Chesapeake , but these are offshore, deepwater pound nets (DeAlteris and Silva 2007) not likely to catch blue catfish. Alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis), collectively referred to as river herring, and American shad (Alosa sapidissima) are also caught in pound net and gillnet fisheries in the Chesapeake Bay. These species are highly depleted relative to historic levels (ASMFC 2007; ASMFC 2012b) and so are included here as species of concern. Finally, spotted seatrout (Cynoscion nebulosus) is caught in gillnets, and is a species of concern, but because it does not have a major overlap with blue catfish due to salinity preferences, it accounts for a very small fraction of the catch (only around 1% of the catch–Appendix 1 and Appendix 2), and was, therefore, also not included in the assessment.

There are also many other fish species caught alongside blue catfish. In Maryland, for example, striped bass (Morone saxatilis) and white perch (Morone americana) are occasionally caught (5 for every 5,000 lbs of catfish) in fyke nets, pound nets, and seine nets targeted at blue catfish, and are always released alive (Steve Vilnit pers. comm., based on information from commercial fishermen). Indeed, gillnets are primarily a winter gear type targeted at striped bass, and blue catfish are actually the bycatch (Steve Vilnit, MDNR, Rachael Maulorico, VMRC, pers. comm.) (Maryland gillnets are a very minor part of the overall catch of blue catfish and of the gillnet

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catch of blue catfish, however (NOAA pers. comm.)). In Virginia, the pound nets that account for the majority of blue catfish are more likely those that also catch yellow perch (Perca flavescens), rather than those that catch species like striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus)(Joe Grist, VMRC, pers. comm.). Landings made with fish pots and traps (aka hoop nets) in Virginia (the biggest single fishery for blue catfish in terms of landings in either state (NOAA pers. comm.)) may be directed blue catfish fisheries or they may be fisheries targeting croaker (Micropogonias undulatus) or spot (Leiostomus xanthurus) (Joe Grist, pers. comm.). Other finfish species caught alongside blue catfish can be found in Appendices 1 and 2. None of these fish species is a species of concern, and therefore not likely to score lower than the other species noted above. For this reason, they are not included in this assessment.

Criterion 2 Assessment

AMERICAN SHAD


Scoring Guidelines (same as Factor 1.1 above)


Medium

American shad has a medium inherent vulnerability, with a FishBase score of 51/100 (Froese and Pauly 2014).




High Concern

While there are no recent estimates of biomass, according to the 2007 stock assessment, all stocks are highly depressed from their historic levels and are at an all-time low (ASMFC 2007). See the Seafood Watch striped bass assessment for a more detailed account.

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Low Concern

The mortality from fishing cannot be reliably separated from natural mortality (ASMFC 2007). Benchmarks for total mortality (including natural mortality, fishing mortality and all other anthropogenic mortalities) have been established for American shad stocks from Maine through North Carolina (ASMFC 2007). Where known total mortality estimates exceed benchmarks throughout this range. See Seafood Watch striped bass report for more detail. A moderate score was selected for fishing mortality in the striped bass fishery, where shad is a landed species. As noted above, it is unknown if shad is caught in the gillnet fisheries that land blue catfish. Furthermore, directed fishing for shad in the Chesapeake Bay has been limited since January 1, 2013 to states and jurisdictions that develop a sustainable fishery management plan, and only the Potomac River Fisheries Commission has done so (i.e., the states of Virginia and Maryland have not). So, directed fishing is likely very limited in the Chesapeake Bay. States are also required to submit a habitat plan for shad, regardless of whether they develop fishery management plans. According to those reports, barriers to migration and climate change are the greatest threats to shad (http://www.asmfc.org/species/shad-river-herring). For these reasons, a rating of low concern is awarded for this factor.

Factor 2.4–Discard Rate


< 20%

Total gillnet landings for 2013 in both Maryland and Virginia combined were 215,259 lbs (NOAA 2014) and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore, the overall discard rate is 0.0000004%. Rationale No bait is used in gillnets (Steve Vilnit, pers. comm.), therefore discards/landings were calculated.

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ATLANTIC STURGEON








High

Atlantic sturgeon have high inherent vulnerability (FishBase score of 85/100) due to their late age at sexual maturity, their reproductive strategy and their long lifespan (Froese and Pauly 2014) (see Table 4).








Very High Concern

In a 1998 stock assessment (before the fishery was closed in April), the Atlantic sturgeon stock was considered overfished, almost to the point of extirpation (Connecticut River, most Chesapeake Bay tributaries, and St. Johns River, Florida) (Kahnle et al. 1998). In 2013, the Atlantic States Marine Fisheries Commission initiated the development of a coastwide benchmark stock assessment for Atlantic sturgeon to evaluate current stock status, however, the findings are not yet available. At present, not much is known about the Atlantic sturgeon’s stock status, as reliable data are difficult to obtain due to many river systems having few fish, and rivers with more fish being difficult to sample. Of the states conducting long-term monitoring (North Carolina and New York), catch per unit effort (CPUE) has varied

25

significantly since the late 1980s and early 1990s, but appears to be increasing likely due to the current moratorium (ASMFC 2015). In addition, according to the IUCN Red List, Atlantic sturgeon are considered endangered within the range of the fishery (St. Pierre 2006)(ASMFC 2015). As a result, we have rated this factor very high concern. Rationale Atlantic sturgeon are assessed as endangered based on levels of past population declines due to their importantance as commerce to early American and Canadian colonists and their continued overharvesting (for flesh and eggs) through the late 1990s, until the Commission and federal government implemented a coastwide moratorium in 1997 (St. Pierre 2006)(ASMFC 2015). Since the turn of the century, the continued low levels of stocks can be attributed to poor water quality, changes in habitat from development, dredging, dam construction, and mortality from bycatch fishing (Kahnle et al. 1998).








Very Low Concern

A tagging program conducted from 1996 to 2006 by the U.S. Fish and Wildlife Service found Atlantic sturgeon are caught mainly in gillnets and pound nets; very few are caught in other gears (USFWS 2007). Of the over 2,000 fish collected during this program, only 11 were dead upon arrival (USFWS 2007), suggesting few are killed by the fisheries that catch them. In addition, it is unlikely that Atlantic sturgeon are caught in the same gears as blue catfish as their habitats do not overlap (shortnose sturgeon are considered an estuarine species and Atlantic sturgeon are primarily marine, whereas blue catfish are primarily freshwater with a salinity tolerance of 14ppt)(Vilnit 2015). Indeed, in Maryland there have been no documented interactions between the blue catfish fishery and Atlantic or shortnose sturgeon (Vilnit 2015). If improved data collection and monitoring were in place that could corroborate these findings, Atlantic and shortnose sturgeon could be removed from this assessment altogether. For now, a

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rating of very low concern is applied to all fisheries.



< 20%

Total fyke net landings for 2013 in both Maryland and Virginia combined were 2,259 lbs (NOAA 2014) and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore, the overall discard rate is 0.00004%. Rationale No bait is used in fyke nets (pers. comm. Steve Vilnit), therefore, discards/landings were calculated.


< 20%

Total gillnet landings for 2013 in both Maryland and Virginia combined were 215,259 lbs (NOAA 2014) and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore the overall discard rate is 0.0000004%. Rationale No bait is used in gillnets (Steve Vilnit, pers. comm.), therefore discards/landings were calculated.


< 20%

Total pound net landings for 2013 in both Maryland and Virginia combined were 235,818 lbs (NOAA 2014) and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore the overall discard rate is 0.0000004%. Rationale No bait is used in pound nets (Steve Vilnit, pers. comm.), therefore discards/landings were calculated.


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< 20%


United States Chesapeake Bay, Trap net

< 20%

The blue catfish fishery in both Maryland and Virginia combined, averages 1500 lbs of blue catfish per 100 lbs of bait fished (Steve Vilnit, pers. comm.), or approximately 49466.9 lbs of bait per landings/year. Total landings for 2013 were 2,601,454 pounds and total discards for 2012 were 742,004 lbs, therefore the overall discard rate is 6.7%(NOAA 2014)(Steve Vilnit, pers. comm.).







High

Diamondback terrapins have high inherent vulnerability due to their age at sexual maturity (7 years), their reproductive strategy (4-8 eggs per clutch several times per year, up to 40 eggs per year) and their long lifespan (50 years) (Park 2000)(MDTT 2001)(SFW 2015).




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High Concern

Diamondback terrapins live along the U.S. Atlantic Coast from Cape Cod to Galveston Bay in the Gulf of Mexico (Roosenburg 1991) and throughout that range the population sizes in the states are primarily unknown or declining and few are considered stable (Seigel and Gibbons 1995)(Butler, Heinrich et al. 2006). There are seven distinct subspecies, which are managed as different units. Moving south along the coast, population sizes tend to decrease so that those in Cape Cod and Chesapeake Bay are the highest, and those in the Gulf of Mexico and south of Chesapeake Bay are low and of concern (Roosenburg 2001). The Tortoise & Freshwater Turtle Specialist Group of the IUCN classified the species as Near Threatened (IUCN 1996)(IUCN 2012). Diamondback terrapins are also federally recognized as a species of special concern by the U.S. Fish and Wildlife Service. State listings vary widely and some terrapin status is not listed by state, therefore, we use the federal listing for stock status http://www.fws.gov/northeast/ecologicalservices/turtle/month/diamondback.html (species of special concern). Rationale Terrapin soup was considered a delicacy in the 18th and 19th centuries, and their populations were drastically reduced, almost to the point of extinction (Coker 1920). Presently, terrapins face numerous threats that decrease population sizes, including habitat loss, barriers to nesting habitat, predation, wounds from boat propellers, and entrapment/drowning in crab nets and pots (Roosenburg 1991)(Tulipani 2014). In Virginia, the diamondback terrapin is now protected by law and it is illegal to collect or possess it.






Low Concern

There is no formal stock assessment of diamondback terrapins, therefore, the effects of fishing mortality is unknown. There have been, however, no documented interactions between the blue catfish fishery and diamondback terrapins. In Maryland specifically, no terrapins have been observed as bycatch in fyke

http://www.fws.gov/northeast/ecologicalservices/turtle/month/diamondback.html

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nets (Vilnit 2015). Therefore, it is most likely that the fisheries catching blue catfish are not impeding recovery of this species. However, the paucity of data introduces some uncertainty, so we have rated this factor low concern rather than very low concern. Rationale The blue catfish fishery is mainly focused in freshwater areas, and although terrapins occur there, time of the year is important with regards to their survival. In the early spring, when water temperatures are below 15°C, there likely is little threat because most species of turtles can remain submerged for a prolonged period of time and thus survive the threat of being caught in a fyke net. However, as the water warms, the threat to terrapins is greater and mortality rates tend to be higher (Fratto et al. 2008)(Roosenburg 2015).



< 20%

Total fyke net landings for 2013 in both Maryland and Virginia combined were 2,259 lbs (NOAA 2014) and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore the overall discard rate is 0.00004%. Rationale No bait is used in fyke nets (pers. comm. Steve Vilnit), therefore discards/landings were calculated.


< 20%

Total gillnet landings for 2013 in both Maryland and Virginia combined were 215,259 lbs (NOAA 2014)and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore the overall discard rate is 0.0000004%. Rationale No bait is used in gillnets (Steve Vilnit, pers. comm.), therefore discards/landings were calculated.


< 20%

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RIVER HERRING





Medium

Alewife and blueback herring are collectively referred to as river herring. Given the similarity in appearance between the two species and the general overlap in habitat utilization, ASMFC manages and assesses both species together. The FishBase vulnerability score is 51 for blueback herring and 29 for alewife. Together, blueback herring and alewife inherent vulnerability is deemed medium.





High Concern

The most recent stock assessment for river herring found that of the 52 stocks of alewife and blueback herring for which data were available, 23 were depleted relative to historic levels, one stock was increasing, and the status of 28 stocks could not be determined because the time-series of available data was too short. The ‘depleted’ determination was used instead of ‘overfished’ and ‘overfishing’ because many factors, not just directed and incidental fishing, are contributing to the declining abundance of river herring (ASMFC 2012b). Due to this, we have rated this factor high concern.

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Low Concern

The most recent stock assessment (ASMFC 2012b) estimates of abundance and fishing mortality could not be developed because of the lack of adequate data. However, beginning January 1, 2012, directed fisheries for river herring in state waters are prohibited unless the state or jurisdiction has a sustainable management plan reviewed by the Technical Committee and approved by the Management Board of the ASMFC. No plans have been approved for Virginia or Maryland or other jurisdiction in the Chesapeake Bay for river herring (http://www.asmfc.org/species/shad-river-herring). States are also required to submit a habitat plan for river herring, regardless of whether they develop fishery management plans. According to those reports, barriers to migration and climate change are the greatest threats to river herring (http://www.asmfc.org/species/shad-river-herring). As there is still uncertainty regarding bycatch of river herring in fisheries that land blue catfish, we have scored this factor low concern rather than very low concern.



< 20%



< 20%

Total pound net landings for 2013 in both Maryland and Virginia combined were 235,818 lbs (NOAA 2014) and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore the overall discard rate is 0.0000004%.

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Rationale No bait is used in pound nets (Steve Vilnit, pers. comm.), therefore discards/landings were calculated.

SHORTNOSE STURGEON








High

Shortnose sturgeon have high inherent vulnerability (FishBase score of 83/100) due to their moderate age at sexual maturity, their reproductive strategy and their long lifespan (Froese and Pauly 2014) (see Table 5). Rationale

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Table 4. Life-history characteristics for shortnose sturgeon








Very High Concern

A formal population assessment for shortnose sturgeon has not been conducted in the Chesapeake Bay region, so there is no formal metric for abundance and, in general, there is a paucity of information with respect to the shortnose population in the Chesapeake Bay area (NMFS 1998).

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However, according to the IUCN Red List, shortnose sturgeon are considered endangered within the range of the fishery, therefore, we have rated this factor very high concern (Friedland 2004). Rationale Shortnose sturgeon are assessed as endangered based on levels of past population declines due to commercial exploitation that occurred throughout its range from Colonial times until the 1950s (NOAA Fisheries 2014). Dam construction, mostly during the period of industrial growth (late 1800s-early 1900s) may have also resulted in considerable loss of suitable habitat. Shortnose sturgeon populations are continually depressed because of pollution of many large northeastern river systems, habitat alterations from discharges, dredging or disposal of material into rivers and other development activities involving estuarine/ riverine mudflats and marshes (NOAA Fisheries 2014).








Very Low Concern

A tagging program conducted from 1996 to 2006 by the U.S. Fish and Wildlife Service found shortnose sturgeon are caught mainly in gillnets and pound nets, though they are also caught in catfish traps and fyke nets (USFWS 2007). Of the over 2,000 fish (Atlantic and shortnose) collected during this program, only 11 were dead upon arrival (USFWS 2007), suggesting few are killed by the fisheries that catch them (also e.g.,NMFS 2010). In addition, it is unlikely that Atlantic sturgeon are caught in the same gears as blue catfish as their habitats do not overlap (shortnose sturgeon are considered an estuarine species and Atlantic sturgeon are primarily marine, whereas blue catfish are primarily freshwater with a salinty tolerance of 14 ppt)(Vilnit 2015). Indeed, in Maryland there have been no documented interactions between the blue catfish fishery and Atlantic or shortnose sturgeon (Vilnit 2015). If improved data collection and monitoring were in place that could corroborate these findings, Atlantic and shortnose sturgeon could be removed from this assessment altogether. For now, a rating of very low concern is applied to all fisheries.

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< 20%

Total fyke net landings for 2013 in both Maryland and Virginia combined were 2,259 lbs (NOAA 2014) and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore the overall discard rate is 0.00004%. Rationale No bait is used in fyke nets (pers. comm. Steve Vilnit), therefore discards/landings were calculated.


< 20%



< 20%



< 20%

Total pound net landings for 2013 in both Maryland and Virginia combined were 218,044 lbs (NOAA 2014) and total discards were 0.001 lbs (Steve Vilnit, pers. comm.), therefore the overall discard rate is

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0.0000004%. Rationale No bait is used in pound nets (Steve Vilnit, pers. comm.), therefore discards/landings were calculated.


< 20%

The blue catfish fishery in both Maryland and Virginia combined, averages 1500 lbs of blue catfish per 100 lbs of bait fished (Steve Vilnit, pers. comm.), or approximately 49466.9 lbs of bait per landings/year. Total landings for 2013 were 2,601,454 pounds and total discards for 2012 were 742,004 lbs, therefore the overall discard rate is 6.7%(NOAA 2014)(Steve Vilnit, pers. comm.).

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Criterion 3: Management effectiveness Management is separated into management of retained species (harvest strategy) and management of non-retained species (bycatch strategy).

The final score for this criterion is the geometric mean of the two scores. The Criterion 3 rating is determined as follows:

• Score >3.2=Green or Low Concern • Score >2.2 and <=3.2=Yellow or Moderate Concern • Score <=2.2 or either the Harvest Strategy (Factor 3.1) or Bycatch Management Strategy

(Factor 3.2) is Very High Concern = Red or High Concern Rating is Critical if either or both of Harvest Strategy (Factor 3.1) and Bycatch Management Strategy (Factor 3.2) ratings are Critical.

Criterion 3 Summary

Region / Method Management of Retained Species

Management of Non-Retained Species

Overall Recommendation


3.000 3.000 Yellow(3.000)


3.000 3.000 Yellow(3.000)


3.000 3.000 Yellow(3.000)


3.000 3.000 Yellow(3.000)


3.000 3.000 Yellow(3.000)

Factor 3.1: Harvest Strategy

Scoring Guidelines

Seven subfactors are evaluated: Management Strategy, Recovery of Species of Concern, Scientific Research/Monitoring, Following of Scientific Advice, Enforcement of Regulations, Management Track Record, and Inclusion of Stakeholders. Each is rated as ‘ineffective,’ ‘moderately effective,’ or ‘highly effective.’

• 5 (Very Low Concern)—Rated as ‘highly effective’ for all seven subfactors considered. • 4 (Low Concern)—Management Strategy and Recovery of Species of Concern rated ‘highly

effective’ and all other subfactors rated at least ‘moderately effective.’

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• 3 (Moderate Concern)—All subfactors rated at least ‘moderately effective.’ • 2 (High Concern)—At minimum, meets standards for ‘moderately effective’ for Management

Strategy and Recovery of Species of Concern, but at least one other subfactor rated ‘ineffective.’

• 1 (Very High Concern)—Management exists, but Management Strategy and/or Recovery of Species of Concern rated ‘ineffective.’

• 0 (Critical)—No management exists when there is a clear need for management (i.e., fishery catches threatened, endangered, or high concern species), OR there is a high level of Illegal, unregulated, and unreported fishing occurring.

Factor 3.1 Summary

Factor 3.1: Management of fishing impacts on retained species Region / Method Strategy Recovery Research Advice Enforce Track Inclusion United States Chesapeake Bay Fyke Net

Moderately Effective

N/A Moderately Effective

Highly Effective

Highly Effective


Highly Effective




Highly Effective

Highly Effective


Highly Effective




Highly Effective

Highly Effective


Highly Effective




Highly Effective

Highly Effective


Highly Effective




Highly Effective

Highly Effective


Highly Effective

Subfactor 3.1.1 – Management Strategy and Implementation

Considerations: What type of management measures are in place? Are there appropriate management goals, and is there evidence that management goals are being met? To achieve a highly effective rating, there must be appropriate management goals, and evidence that the measures in place have been successful at maintaining/rebuilding species.






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In Maryland, the Department of Natural Resources, Fisheries Service, is responsible for managing commercial and recreational fishing, and in Virginia, the Virginia Marine Resources Commission (VMRC) has jurisdiction over commercial fisheries, which includes the harvest of catfish from tidal waters (MDNR 2012a)(Bob Greenlee, VDGIF, pers.comm.). Fisheries in the Potomac River are regulated by the Potomac River Fisheries Commission (PRFC 2015). There is currently no fishery management plan for blue catfish, but a bay-wide management plan is in the process of being developed (ICTF 2014). In February 2014, the ICTF produced a draft report that included current blue catfish management efforts and suggested seven recommendations, which was reviewed by the Chesapeake Bay Program's Scientific and Technical Advisory Committee (STAC). The STAC identified important scientific gaps and recommended that more information be collected before a FMP is implemented (Bilkovic et al. 2014). Blue catfish populations are increasing and spreading in the Chesapeake Bay (Schloesser et al. 2011). As of 2011, blue catfish are considered to be invasive and managers are concerned that their high abundance may be having a negative impact (due to predation and competition) on some of the native Chesapeake Bay species (Garman et al. 2013). As a result, managers are actively focusing on ways to reduce the abundance of blue catfish, prevent their expansion into new rivers, and limit any negative ecological impacts (TBN 2012)(ASMFC 2012)(CWG 2012). As a result, we have rated this factor moderately effective. Rationale There are few regulations in place for blue catfish fisheries. In Virginia, only one fish over 81 cm (32 in) can be caught per day (VMRC 2015). This regulation applies to both commercial and recreational fishers, and is in place mainly due to health concerns, as large blue catfish can contain high levels of polychlorinated biphenyls (PCBs) and other harmful compounds (Greenlee B 2011)(Hale et al. 2013). In non-tidal freshwater areas, a daily limit of 20 blue catfish per day is in place, but in other areas, there is no limit on blue catfish catch less than 81 cm (DGIF 2015)(VMRC 2015). In Maryland, there is no creel or size limit in tidal, non-tidal or commercial blue catfish fisheries (MDNR 2015). It is illegal in Maryland, Virginia, and Delaware to transport and release live blue catfish.

Subfactor 3.1.2 – Recovery of Species of Concern

Considerations: When needed, are recovery strategies/management measures in place to rebuild overfished/threatened/ endangered species or to limit fishery’s impact on these species and what is their likelihood of success? To achieve a rating of ‘highly effective,’ rebuilding strategies that have a high likelihood of success in an appropriate timeframe must be in place when needed, as well as measures to minimize mortality for any overfished/threatened/endangered species.

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N/A

Since there are no overfished, depleted, endangered or threatened species targeted or retained in the blue catfish fishery, we have rated this factor not applicable.

Subfactor 3.1.3 – Scientific Research and Monitoring

Considerations: How much and what types of data are collected to evaluate the health of the population and the fishery’s impact on the species? To achieve a ‘highly effective’ rating, population assessments must be conducted regularly and they must be robust enough to reliably determine the population status.







There is annual monitoring of blue catfish via fisheries programs at Virginia Institute of Marine Science (VIMS), Virginia Commonwealth University (VCU), Virginia Department of Game and Inland Fisheries (VDGIF), Smithsonian Environmental Research Center (SERC), District of Columbia Fisheries, University of Maryland, Maryland Department of Natural Resources (MDDNR), and University of Maryland (ICTF 2014). Nevertheless, because some information is lacking, such as total catches, and further information is needed to determine their impact on native species, we have rated this factor moderately effective. Rationale The annual monitoring of blue catfish in Virginia and Maryland is to determine abundance, growth rates, size structure and other biological parameters (Greenlee B 2011)(Latour et al. 2013). In addition, there are ongoing studies to determine the diet composition of blue catfish and their impact on native species

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(Greenlee B 2011)(Garman et al. 2013)(Ogburn 2014)(Orth and Schmitt 2014)(SERC 2014). However, no formal population assessments have been conducted. Commercial catches of blue catfish are monitored, but total catches have been hard to quantify because not all catfish catches are identified to the species level (VMRC 2010a). However, Maryland and Virginia now require commercial fishermen to report catfish catch identified to the species level, which will lead to a substantial improvement in the ability of managers to track catches of non-native catfish (Matt Ogburn, SERC, pers. comm.).

Subfactor 3.1.4 – Management Record of Following Scientific Advice

Considerations: How often (always, sometimes, rarely) do managers of the fishery follow scientific recommendations/advice (e.g., do they set catch limits at recommended levels)? A ‘highly effective’ rating is given if managers nearly always follow scientific advice.






Highly Effective

There has been no formal assessment of the blue catfish fishery. However, management has used scientific advice for regulating catch limits due to polychlorinated biphenyls (PCBs) and other harmful compound accumulation (Greenlee B. 2011)(Hale et al. 2012). Studies are underway in order to ascertain population size and distribution, movement information, removal rates needed to elicit a response in the system, and gear effectiveness (SERC 2014). In addition, management objectives are focusing on how to reduce, not increase, blue catfish populations in the Chesapeake Bay.

Subfactor 3.1.5 – Enforcement of Management Regulations

Considerations: Do fishermen comply with regulations, and how is this monitored? To achieve a ‘highly effective’ rating, there must be regular enforcement of regulations and verification of compliance.



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Highly Effective

Since blue catfish are invasive in the Chesapeake Bay and management is focusing on ways to decrease their abundance, there are no TACs set, nor is there a need for enforcement. A bay-wide management plan for blue catfish is in the process of being developed (ICTF 2014). As a result, we have rated this factor highly effective. Rationale An important exception is the regulation prohibiting transport and release of live blue catfish from one location to another. It is widely acknowledged that such transfers have occurred and that enforcement is difficult.

Subfactor 3.1.6 – Management Track Record

Considerations: Does management have a history of successfully maintaining populations at sustainable levels or a history of failing to maintain populations at sustainable levels? A ‘highly effective’ rating is given if measures enacted by management have been shown to result in the long-term maintenance of species overtime.







There are a few management regulations in place for blue catfish fisheries in the Chesapeake Bay, however, there is no formal fishery management plan for blue catfish. Their population appears to be thriving as they have expanded their range since they were introduced into the area, and abundance has been increasing (Greenlee 2010; Schloesser et al. 2011; Tuckey and Fabrizio 2011)(Garman et al. 2013). Since management is only recently focusing on ways to reduce the abundance of blue catfish, prevent their expansion into new rivers, and limit any negative ecological impacts, we have rated this factor

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moderately effective.

Subfactor 3.1.7 – Stakeholder Inclusion

Considerations: Are stakeholders involved/included in the decision-making process? Stakeholders are individuals/groups/organizations that have an interest in the fishery or that may be affected by the management of the fishery (e.g., fishermen, conservation groups, etc.). A ‘highly effective’ rating is given if the management process is transparent and includes stakeholder input.






Highly Effective

A bay-wide management plan for blue catfish is currently being developed (ICTF 2014) that will incorporate and solicit input from relevant government and non-governmental agencies, academic institutions and private sector stakeholders in Delaware, Virginia, Maryland, Pennsylvania and the District of Columbia. As a result, we have rated this factor highly effective (CBP 2012b). Rationale An Invasive Catfish Task Force (ICTF) has been created with the goal of coordinating the best available science and developing precautionary management approaches aimed at mitigating the spread and minimizing the impacts of invasive catfish species on the Chesapeake Bay native fauna (CBP 2012). The role of the ICTF is to incorporate all available information on blue and flathead catfish to develop an agreed upon management strategy for handling these invasive species across all jurisdictions (ICTF 2014). Members of the task force include experts from the Virginia Department of Game and Inland Fisheries, Virginia Marine Resources Commission, Virginia Institute of Marine Science, Virginia Commonwealth University, Potomac River Fisheries Commission, D.C. Department of the Environment, Maryland Department of Natural Resources, Atlantic States Marine Fisheries Commission, the Smithsonian Environmental Research Center and the National Oceanic and Atmospheric Administration (CBP 2012b)(ICTF 2014).

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Bycatch Strategy

Factor 3.2: Management of fishing impacts on bycatch species Region / Method All Kept Critical Strategy Research Advice Enforce United States Chesapeake Bay Fyke Net

No No Moderately Effective


Highly Effective

Highly Effective




Highly Effective

Highly Effective




Highly Effective

Highly Effective




Highly Effective

Highly Effective




Highly Effective

Highly Effective

Subfactor 3.2.1 – Management Strategy and Implementation

Considerations: What type of management strategy/measures are in place to reduce the impacts of the fishery on bycatch species and how successful are these management measures? To achieve a ‘highly effective’ rating, the primary bycatch species must be known and there must be clear goals and measures in place to minimize the impacts on bycatch species (e.g., catch limits, use of proven mitigation measures, etc.).







There is no formal FMP for blue catfish, however, there are some general bycatch management measures in place. Bycatch is thought to be relatively rare and whatever bycatch is caught is released alive (Vilnit 2015). For turtles specifically, NOAA has required measures, such as gear modifications, changes to fishing practices and time/area closures, to reduce sea turtle bycatch in the Chesapeake Bay region. Moreover, NOAA is involved in cooperative gear research projects designed to reduce sea turtle bycatch in the Chesapeake Bay pound net fishery (NMFS SFSC 2001).

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For river herring, where 23 of the 52 stocks are considered depleted (ASMFC 2012b), directed fisheries in state waters are prohibited unless the state or jurisdiction has a sustainable management plan reviewed by the Technical Committee and approved by the Management Board of the ASMFC. However, no specific plans for river herring have been approved for Virginia or Maryland, or other jurisdictions in the Chesapeake Bay (http://www.asmfc.org/species/shad-river-herring). For American shad, which are highly depressed from their historic levels, and at an all-time low, directed fishing in the Chesapeake Bay has been limited (since January 2013) to states and jurisdictions that develop a sustainable fishery management plan, and only the Potomac River Fisheries Commission has done so (i.e., the states of Virginia and Maryland have not). So, directed fishing is likely very limited in the Chesapeake Bay. States are also required to submit a habitat plan for shad, regardless of whether they develop fishery management plans (ASMFC 2007). It is illegal to fish for, catch or harvest Atlantic sturgeon and shortnose sturgeon, which are considered endangered (Chesapeake Bay News 2012)(CBP 2015). In Virginia, it is illegal to collect diamondback terrapins, a species of concern, for commercial or personal use (VIMS 2015b). Because there is no specific bycatch management plan, and it is unclear if one is necessary, we have rated this factor moderately effective.

Subfactor 3.2.2 – Scientific Research and Monitoring

Considerations: Is bycatch in the fishery recorded/documented and is there adequate monitoring of bycatch to measure fishery’s impact on bycatch species? To achieve a ‘highly effective’ rating, assessments must be conducted to determine the impact of the fishery on species of concern, and an adequate bycatch data collection program must be in place to ensure bycatch management goals are being met.







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It is unclear which species are caught as bycatch in the blue catfish fishery, and to what extent. It is thought that bycatch is minimal (Steve Vilnit, MDNR; Howard Townsend, NOAA; Joe Grist, VMRC; Rachael Maulorico, VMRC, pers. comm.), but it remains ambiguous whether there is a need for observer coverage to monitor bycatch. Due to the lack of specific information, we have rated this factor moderately effective.

Subfactor 3.2.3 – Management Record of Following Scientific Advice

Considerations: How often (always, sometimes, rarely) do managers of the fishery follow scientific recommendations/advice (e.g., do they set catch limits at recommended levels)? A ‘highly effective’ rating is given if managers nearly always follow scientific advice.






Highly Effective

There has been no formal assessment of the blue catfish fishery. However, management has used scientific advice for regulating catch limits due to polychlorinated biphenyls (PCBs) and other harmful compound accumulation (Greenlee B 2011)(Hale et al. 2012) as well as for gathering additional data on blue catfish life history to implement a FMP. Hence, it is likely that scientific advice would also be used with respect to bycatch management; therefore, we have rated this factor highly effective.

Subfactor 3.2.4 – Enforcement of Management Regulations

Considerations: Is there a monitoring/enforcement system in place to ensure fishermen follow management regulations and what is the level of fishermen’s compliance with regulations? To achieve a ‘highly effective’ rating, there must be consistent enforcement of regulations and verification of compliance.




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Highly Effective

Since blue catfish are invasive in the Chesapeake Bay, management is focusing on ways to decrease their abundance. In addition, there is thought to be minimal bycatch and therefore no need for enforcement. A bay-wide management plan for blue catfish is in the process of being developed (TBN 2012)(Bilkovic et al. 2014). As a result, we have rated this factor highly effective.

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Criterion 4: Impacts on the habitat and ecosystem This Criterion assesses the impact of the fishery on seafloor habitats, and increases that base score if there are measures in place to mitigate any impacts. The fishery’s overall impact on the ecosystem and food web and the use of ecosystem-based fisheries management (EBFM) principles is also evaluated. Ecosystem-based fisheries management aims to consider the interconnections among species and all natural and human stressors on the environment.

The final score is the geometric mean of the impact of fishing gear on habitat score (plus the mitigation of gear impacts score) and the ecosystem-based fishery management score. The Criterion 2 rating is determined as follows:


Rating cannot be Critical for Criterion 4.

Criterion 4 Summary

Region / Method Gear Type and Substrate

Mitigation of Gear Impacts

EBFM Overall Recomm.


3.00:Low Concern

0.00:No Effective Mitigation


Green (3.873)


3.00:Low Concern



Green (3.873)


3.00:Low Concern



Green (3.873)


3.00:Low Concern



Green (3.873)


3.00:Low Concern



Green (3.873)

Justification of Ranking

Factor 4.1 – Impact of Fishing Gear on the Habitat/Substrate

Scoring Guidelines

• 5 (None)—Fishing gear does not contact the bottom

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• 4 (Very Low)—Vertical line gear • 3 (Low)—Gears that contacts the bottom, but is not dragged along the bottom (e.g., gillnet,

bottom longline, trap) and is not fished on sensitive habitats. Bottom seine on resilient mud/sand habitats. Midwater trawl that is known to contact bottom occasionally

• 2 (Moderate)—Bottom dragging gears (dredge, trawl) fished on resilient mud/sand habitats. Gillnet, trap, or bottom longline fished on sensitive boulder or coral reef habitat. Bottom seine except on mud/sand

• 1 (High)—Hydraulic clam dredge. Dredge or trawl gear fished on moderately sensitive habitats (e.g., cobble or boulder)

• 0 (Very High)—Dredge or trawl fished on biogenic habitat, (e.g., deep-sea corals, eelgrass and maerl) Note: When multiple habitat types are commonly encountered, and/or the habitat classification is uncertain, the score will be based on the most sensitive, plausible habitat type.


Low Concern

Fyke nets are a passive gear that typically contact bottom habitats (FAO 2015), but fkye nets targeting blue catfish tend to be set on gravel/sand/silt/mud (Graham 1999), which is much less sensitive to the impact of fishing gear (Tietze et al. 2011). Because of this, they likely have minimal effect on habitat (SFW 2015). As a result, we have rated this factor low concern.

Rationale Blue catfish can also be found in areas that have complex structures, such as rock piles (Fabrizio 2010a). Some of these habitats may be sensitive to damage from fishing gears. However, the impact from the fishing gears used to capture blue catfish is likely not substantial.


Low Concern

Gillnets are a passive gear type that contact bottom habitats (NOAA Fisheries 2014f), but gillnets targeting blue catfish tend to be set on gravel/sand/silt/mud (Graham 1999), which is much less sensitive to the impact of fishing gear (Tietze et al. 2011). Because of this, they likely have minimal effect on habitat (SFW 2015). As a result, have rated this factor low concern. Rationale Blue catfish can also be found in areas that have complex structures, such as rock piles (Fabrizio 2010a).

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Some of these habitats may be sensitive to damage from fishing gears. However, the impact from the fishing gears used to capture blue catfish are likely not substantial.


Low Concern

Pound nets are a passive gear type that typically contact bottom habitats (NOAA Fisheries 2014e), but pound nets targeting blue catfish tend to be set on gravel/sand/silt/mud (Graham 1999), which is much less sensitive to the impact of fishing gear (Tietze et al. 2011). Because of this, they likely have minimal effect on habitat (SFW 2015). As a result, we have rated this factor low concern. Rationale Blue catfish can also be found in areas that have complex structures, such as rock piles (Fabrizio 2010a). Some of these habitats may be sensitive to damage from fishing gears. However, the impact from the fishing gears used to capture blue catfish are likely not substantial.


Low Concern

Seine nets are an active gear type that typically contact bottom habitats, but seine nets targeting blue catfish tend to be used on gravel/sand/silt/mud (Graham 1999), which is much less sensitive to the impact of fishing gear (Tietze et al. 2011). In most cases, the impact from seines would be expected to be minor and temporary (Tietze et al. 2011)(SFW 2015), therefore, we have rated this factor low concern.


Low Concern

Since pots are a passive gear type set on gravel/sand/silt/mud and therefore have minimal effect on habitat, we have rated this factor low concern. Rationale Blue catfish can also be found in areas that have complex structures, such as rock piles (Fabrizio 2010a). Some of these habitats may be sensitive to damage from fishing gears. However, the impact from the fishing gears used to capture blue catfish are not substantial.

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Factor 4.2 – Mitigation of Gear Impacts

Scoring Guidelines

• +1 (Strong Mitigation)—Examples include large proportion of habitat protected from fishing (>50%) with gear, fishing intensity low/limited, gear specifically modified to reduce damage to seafloor and modifications shown to be effective at reducing damage, or an effective combination of ‘moderate’ mitigation measures.

• +0.5 (Moderate Mitigation)—20% of habitat protected from fishing with gear or other measures in place to limit fishing effort, fishing intensity, and spatial footprint of damage caused from fishing.

• +0.25 (Low Mitigation)—A few measures are in place (e.g., vulnerable habitats protected but other habitats not protected); there are some limits on fishing effort/intensity, but not actively being reduced.

• 0 (No Mitigation)—No effective measures are in place to limit gear impacts on habitats. United States Chesapeake Bay, Fyke Net





No Effective Mitigation

Since there is minimal impact on the habitat by this gear type, and there are no controls in place on blue catfish fishing intensity due to their invasive status, we have rated this factor ‘no effective mitigation.’

Factor 4.3 – Ecosystem-Based Fisheries Management

Scoring Guidelines

• 5 (Very Low Concern)—Substantial efforts have been made to protect species’ ecological roles and ensure fishing practices do not have negative ecological effects (e.g., large proportion of fishery area is protected with marine reserves, and abundance is maintained at sufficient levels to provide food to predators).

• 4 (Low Concern)—Studies are underway to assess the ecological role of species and measures are in place to protect the ecological role of any species that plays an exceptionally large role in the ecosystem. Measures are in place to minimize potentially

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negative ecological effect if hatchery supplementation or fish aggregating devices (FADs) are used.

• 3 (Moderate Concern)—Fishery does not catch species that play an exceptionally large role in the ecosystem, or if it does, studies are underway to determine how to protect the ecological role of these species, OR negative ecological effects from hatchery supplementation or FADs are possible and management is not place to mitigate these impacts.

• 2 (High Concern)—Fishery catches species that play an exceptionally large role in the ecosystem and no efforts are being made to incorporate their ecological role into management.

• 1 (Very High Concern)—Use of hatchery supplementation or fish aggregating devices (FADs) in the fishery is having serious negative ecological or genetic consequences, OR fishery has resulted in trophic cascades or other detrimental impacts to the food web.






Very Low Concern

Because of the high abundance of blue catfish and their likely negative impact on native fauna (Garman et al. 2013)(Ogburn 2014)(Orth and Schmitt 2014), managers are researching the best methods to reduce blue catfish densities and limit their distribution in the Chesapeake Bay (SFGITEC 2012). Therefore, since the direct targeting of blue catfish would likely benefit the native species, we have rated this factor very low concern. Rationale Blue catfish are both important predators and prey. They are opportunistic and feed on fish, small crustaceans, worms, clams, mussels, crabs, insects, and plant matter, among other things (Brown and Dendy 1961)(Minckley 1962)(Perry 1969)(Ogburn 2014)(Orth and Schmitt 2014). As blue catfish grow larger, they consume and/or compete with many native (and some endangered) crustaceans and fishes such as, blue crabs (Callinectes sapidus) Atlantic menhaden (Brevoortia tyrannus), gizzard shad (Dorosoma cepedianum), American shad (Alosa sapidissima), blueback herring (Alosa aestivalis), white perch (Morone americana), Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus), shortnose sturgeon (Acipenser brevirostrum), striped bass (Morone saxatilis), white catfish (Ameiurus catus) and channel catfish (Ictalurus punctatus) (MacAvoy et al. 2009)(VMRC 2010b)(Schloesser et al 2011)(Garman et al. 2011)(Groves et al. 2012)(Garman et al. 2013)(Ogburn 2014)(Orth and Schmitt 2014). Blue catfish are

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also a primary food source for predatory birds in the Chesapeake area, like bald eagles and ospreys and, as such, their high abundance levels may be positively impacting several bird species in this region (Burkhead et al. 1980)(Viverette et al. 2007). Catfish have been found to make up a significant proportion (~30%) of the diets of predatory birds in the Chesapeake Bay (Markham 2004) and some species, like bald eagles, appear to prefer catfish over other fish species (Delong 1990). Blue catfish are also eaten by otters and other fish, like flathead catfish. Because blue catfish are opportunistic, they are thought to detrimentally affect Chesapeake Bay ecology by compromising recovery efforts for anadromous fishes (American shad, Atlantic menhaden, blueback herring, alewife, Atlantic sturgeon, white perch), possibly contributing to declines in abundance of native fishes (white catfish and brown bullhead) and generating top-down trophic cascades (Garman et al. 2011). They also consume other economically important taxa like American eel, spot, blue crab, and softshell clam (Garman et al. 2013), but whether their predation on these species is significant is unknown. Stable isotope analyses of fish tissues from coastal rivers in Virginia show that blue catfish represent a novel trophic level that is significantly higher compared to native predatory fishes (Garman and Macko 1998). Moreover, due to their extremely high biomass (up to 75% in some portions of the rivers), they also increase contaminant levels in bald eagles and other fish-eating birds, and impact existing commercial fisheries by contributing to substantial losses of key fishery resources through predation, and by decreasing gear efficiency when caught in high numbers as bycatch (Garman et al. 2011).

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Acknowledgements Scientific review does not constitute an endorsement of the Seafood Watch® program, or its seafood recommendations, on the part of the reviewing scientists. Seafood Watch® is solely responsible for the conclusions reached in this report.

Seafood Watch® would like to thank three anonymous reviewers for graciously reviewing this report for scientific accuracy.

mailto:[email protected]

mailto:[email protected]

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