Seafood Watch Seafood Report Opah Lampris guttatus Image © Monterey Bay Aquarium Final Report April 27, 2004 (Updated October 22, 2004) Melissa Mahoney Stevens Fisheries Research Analyst Monterey Bay Aquarium MBA Seafood Watch® Opah Report October 22, 2004 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 that originating from species, wild-caught or farmed, that can exist into the long-term through maintained or increased stock abundance and conservation of the structure, function, biodiversity and productivity of the surrounding ecosystem. 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 (www.montereybayaquarium.org) or obtained from the program by emailing [email protected]. The program’s goals are to raise awareness of important ocean conservation issues and to shift the purchasing habits of consumers, restaurateurs and other seafood purveyors to support sustainable fishing and aquaculture practices. 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”, “Proceed with Caution” or “Avoid”. 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® Fishery 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 831-647-6873 or emailing [email protected]. Disclaimer Seafood Watch® strives to have all Seafood Reports reviewed for accuracy and completeness by external scientists with expertise in ecology, fishery 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® Seafood Reports are made possible through a grant from the David and Lucile Packard Foundation. 2 MBA Seafood Watch® Opah Report October 22, 2004 Executive Summary Opah (Lampris guttatus), also known as moonfish, is a solitary pelagic species that inhabits most of the world's temperate and tropical oceans. Almost nothing is known about its life history characteristics or population structure. Opah is not directly targeted by any major commercial fishery, but is caught incidentally and retained in the Hawaii-based longline fishery targeting tuna and billfishes, as well as the California drift gillnet and pelagic longline fisheries. Although opah is managed under a general pelagic fisheries management scheme, no stock assessment has been performed to date, and there are no quotas governing take. Pelagic longline fisheries have been observed to interact with and cause mortalities of protected and endangered marine species, such as sea turtles, seabirds, and marine mammals, as well as other vulnerable fishes such as sharks and rays. Managers and fishers in the U.S. fleet have made great strides in reducing interactions in recent years through changes in regulations and gear modifications. The international fishery, which represents a much larger portion of overall pelagic take, is not monitored, regulated, or required to mitigate protected species interactions. Due to overall fishing mortality, and other natural and anthropogenic factors, population estimates for many species of sea turtles and seabirds are extremely low, so even a minor amount of bycatch mortality may undermine their long-term survival. 3 MBA Seafood Watch® Opah Report October 22, 2004 Table of Sustainability Ranks Sustainability Concern: Concern: Concern: Concern: Criteria Low Moderate High Critical Inherently √ Vulnerability Status of √ Stocks Nature of √ HI Longline √ International Bycatch fishery Habitat √ Effects Management √ HI Longline √ International Effectiveness Overall Evaluation and Seafood Ranking Guidelines: • A seafood product is ranked “Avoid” if a total of two or more criteria are indicated as Concern: High (red) OR if one or more criteria are indicated as Concern: Critical (black) in the table above • A seafood product is ranked “Caution” if a total of three or more criteria are indicated as Concern: Moderate (yellow) OR where the “Status of Stocks” and “Management Effectiveness” criteria are both indicated as Concern: Moderate • A seafood product is ranked “Best Choices” if a total of three or more criteria are indicated as Concern: Low (green) and no remaining criteria are indicated as Concern: High or Concern: Critical Overall Evaluation and Seafood Ranking: HAWAII-BASED: Avoid Proceed with Caution Best Choices INTERNATIONAL: Avoid Proceed with Caution Best Choices 4 MBA Seafood Watch® Opah Report October 22, 2004 Introduction Opah, also commonly known as moonfish, inhabits pelagic environments within all of the world’s temperate and tropical oceans, including the Mediterranean and Caribbean Seas (Russo 1981; Heemstra 1986). In the Eastern Pacific, it ranges from the Gulf of Alaska to south of California (FishBase 2003). Opah is reported to inhabit waters from the surface to 500 meters (m) depth, and is thought to exhibit diel vertical migrations (based on longline catch depths) (NMFS 2001a; Hawn et al. 2002), frequenting the greater depths at night1. Opah is not directly targeted by any major commercial fishery, but is caught incidentally and retained in the Hawaii- based longline fishery targeting tuna and billfishes, as well as the California drift gillnet and pelagic longline fisheries. Because it is not a major target of any fishery, very little is known about the opah’s biology or population structure (Hawn et al. 2002). Historically, moonfish were caught within the now obsolete Japanese drift net fishery (NMFS 2001a; Hawn et al. 2002). Today, most opah (~99%) is caught incidentally by pelagic longline gear targeting tuna, although some individuals are landed by the U.S. coastal albacore and salmon fisheries (WPRFMC 2002). Most opah landed in Hawaii are caught outside the 200 mile U.S. Exclusive Economic Zone (EEZ) surrounding the Main Hawaiian Islands (MHI) or off the atolls and islets that make up the Northwestern Hawaiian Islands (NWHI; see map below) (NMFS 2001a). Opah is generally considered a solitary species (Orkin 1950). From 1991-1999, opah catch in the Western Pacific Region increased. In 2000, however, landings decreased to approximately 318 metric tons (mt; 700,00 lb) for the state of Hawaii, and less than 30 mt (~6,500 lb) for American Samoa (Ito and Machado 2001). In 2000, the opah catch amounted to approximately 3% of the 23.8 million pounds of pelagic species landed by the Hawaii-based longline fleet (WPRFMC 2002). Total opah landings for California-based vessels are unavailable, but observer data from the drift gillnet fishery indicate they are frequently encountered (PFMC 2002). Scope of the analysis and the ensuing recommendation: Because its distribution is circumtropical, opah is caught in many areas around the globe (Pacific, Gulf of Mexico, Caribbean, South Atlantic, etc.). This report, however, deals only with the stocks inhabiting the western central Pacific (U.S. and international). The two California fisheries (pelagic longline and drift gillnet) are not evaluated in this report. 1 M. Seki. 2003. Personal commun. NMFS Laboratory, 2570 Dole Street, Honolulu, Hawaii 96822-2396. 5 MBA Seafood Watch® Opah Report October 22, 2004 Courtesy: NOAA Availability of Science Very little is known about the biology of opah and even less is known about its population structure. There is almost no information on spawning habits, size at maturity, age, growth, or migration patterns (Hawn et al. 2002). Indeed, too little is known about this species to allow an assessment of stock abundance or structure. Consequently, there are no estimates of biomass, optimum yield (OY), or maximum sustainable yield (MSY). The only indication of abundance trends are inferred from catch and effort data, so uncertainty weighs heavily in the overall recommendation. Because few studies on opah have been carried out, few primary literature sources (peer- reviewed journals) were available for this analysis. Most of the abundance and fishery data came from unpublished government reports produced by management