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Seafood Watch Seafood Report Southern Flounder (Paralichthys lethostigma) Gulf of Mexico & South Atlantic Regions Final Report April 6, 2004 Melissa Mahoney Stevens Fisheries Research Analyst Monterey Bay Aquarium About Seafood Watch® and the Seafood Reports 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 the Internet (seafoodwatch.org) or obtained from the Seafood Watch® program by emailing [email protected]. 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® Fisheries 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. 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. Seafood Watch® and Seafood Reports are made possible through a grant from the David and Lucile Packard Foundation. Seafood Watch® Southern Flounder Report April 6, 2004 Executive Summary Southern flounder is a coastal flatfish that supports US commercial and recreational fisheries along the coasts of the Gulf of Mexico (GOM) and Atlantic Ocean, mainly off North Carolina (NC). This species of flatfish is fast growing, short-lived (<10 years) and matures quickly (< 5yrs). Annual commercial landings are significantly higher in the Atlantic (3.5 million pounds in NC) than in the Gulf region (~ 300,000 pounds). In the GOM, the directed commercial fishery for flounders uses seines, hook and line, or gig, none of which have been shown to have significant bycatch or adversely affect habitat. On the Atlantic side pound nets, gillnets, and gigs are used to target southern flounder. Pound nets and gigs are very selective (low bycatch) and are thought to have minimal habitat impacts to estuarine areas where they are used. Deep-water large mesh gillnets in Pamlico Sound, NC, have been shown to cause strandings of protected sea turtles, but measures have been taken to reduce the amount of interactions. Stock status in the GOM is uncertain due to the lack of species-specific fisheries dependent and/or robust independent data. In the Atlantic inshore waters of North Carolina, southern flounder is considered overfished with overfishing occurring. In the GOM, southern flounder is incidentally caught and retained from shrimp trawl operations. This fishery is of greater concern, as trawls have been shown to take excessive amounts of other fishes (mostly immature), invertebrates, and sea turtles respective to shrimp catch. Trawls are also thought to cause moderate alterations to sea bottom habitat in the Gulf. Individual states are responsible for management of southern flounder; interjurisdictional cooperation is achieved through the Gulf States Marine Fisheries Commission. Together these agencies regulate fishing pressure through fishing regulations such as bag limits (recreational) and permit qualifications (commercial). Management is moderately effective with respect to southern flounder stocks, as stock uncertainties need to be addressed, and in North Carolina, where a stock assessment and fishery management plan are currently being developed for a mature fishery. Table of Ranks Sustainability Concern: Concern: Concern: Concern: Criteria Low Moderate High CRITICAL Inherently √ Vulnerability Status of √ (GOM) √ (NC) Stocks Nature of Bycatch √ (GOM - √ (Pound nets, √ (Deep-water incidental take gig) gillnets, NC) from shrimp trawl) Habitat √ (Directed √ (shrimp trawl) Effects fishery) Management √ Effectiveness Overall Seafood Rank: Avoid - Atlantic (NC) Good Alternative – GOM 3 Seafood Watch® Southern Flounder Report April 6, 2004 Introduction The southern flounder (Paralichthys lethostigma) is a large, euryhaline1 flatfish of in the family Bothidae (Hoese and Moore 1998). It inhabits coastal areas around the Gulf of Mexico (GOM) and southern US Atlantic coasts from North Carolina to Florida (particularly off North Carolina), and supports valuable commercial and recreational fisheries in those areas. It is closely related and often confused with two other species, summer flounder (P. dentatus) and gulf flounder (P. albigutta). One distinguishing factor is the absence of ocellated spots on the dorsal surface (Hoese and Moore 1998). The distribution of southern flounder appears to be substrate-related, as they are mainly found on silt/mud substrate (GSMFC 2000; FMRI 2003). Southern flounder inhabit the coastal waters of the GOM to the Caloosahatchee River, in Florida, and are present in the Atlantic Ocean from the Loxahatchee River, Florida up to Albemarle Sound, North Carolina (Fig. 1; Ginsburg 1952; FMRI 2003). Individuals can tolerate wide temperature (~ 5-35˚C) and salinity ranges (~ 0.0- 60.0‰), inhabiting both brackish/freshwater and saltwater environs. Individuals reside in bays and estuaries throughout the spring and summer, migrating offshore in the fall to spawn. The fishery is most active during this period when fish are moving2. Figure 1. Distribution of gulf and southern flounder in the southeastern US (GSMFC 2000). Availability of Science There is a reasonable amount of information pertaining to life history of southern flounder. In the GOM, species-specific fisheries data is extremely limited, which hampers realistic conclusions reached in stock assessments. In the Atlantic, the largest fishery for this species (by 1 Able to tolerate fresh and salt water environs. 2 Carter Watterson. Personal Communication. North Carolina Division of Marine Fisheries. 3441 Arendell St, Morehead City, NC 28557. 4 Seafood Watch® Southern Flounder Report April 6, 2004 volume and value) is off North Carolina, so this evaluation focuses entirely on that state. There is no information related to fisheries or stocks in other Atlantic states. There appears to be sufficient information to assess stocks off NC, although the data series is limited to 12 years (1991-2002). There is no species-specific trade data for southern flounder, so nothing is known about import and export activity. Market Availability Common/Market names The southern flounder is often referred to as southern large flounder, mud flounder, halibut, plie (Louisiana French), southern fluke, and doormat (Reagan and Wingo 1985; Hoese and Moore 1998). When used for sushi or sashimi, flounders are commonly sold as hirame. Seasonal Availability Due to their fall migrations, flounder landings peak between the months of August and November, dropping off significantly in late winter/early spring (GSMFC 2000). Product forms Most GOM states require that southern flounder be landed whole/round form. Consequently, a market survey conducted in 1996 showed that 66% of flounders were sold whole, and 80% of those were sold fresh (GSMFC 2000). The remainder was filleted and sold either fresh or frozen, or processed into value-added products. In North Carolina, southern flounder are sold whole or processed into fillets, which are marketed in both stores and restaurants. Unfortunately, most product loses its identity and becomes simply “flounder”, so it will be difficult for the consumer to identify the species in the marketplace. There is also a premium live fish fishery, which mostly caters to the Asian market. Import/export Statistics US Customs does not record trade of southern flounder individually,