SFP Best Practices Report: Minimizing and managing the impacts of fisheries on bycatch of protected, endangered, and threatened species

Westmeyer M (2013) SFP Best Practices Report: Minimizing and managing the impacts of fisheries on bycatch of protected, endangered, and threatened species. Sustainable Fisheries Partnership, Honolulu, Hawaii

Ecosystem-based fishery management (EBFM), also referred to as the ecosystem approach to fisheries (EAF), considers all the living and non-living components of a marine community when managing fisheries. Target species and the ecosystems in which they live are inextricably tied, and fishing affects ecosystems in ways beyond just the removal of the targeted species. These effects, along with other anthropogenic effects like coastal development and pollution, may cumulatively have a greater impact than direct fishing pressure alone. Reduction of protected, endangered, and threatened (PET) species bycatch is an important component of ecosystem-based fishery management. It is also an issue that attracts a great deal of attention from consumers and conservationists. Seafood suppliers and buyers should work with their source fisheries to quantify, monitor, and reduce any impacts that occur. There are numerous examples around the world that demonstrate that successful PET bycatch reduction and cooperative actions by the seafood supply chain can ensure productive seafood supplies for the future while protecting important components of the marine ecosystem.
In general, PET species fall into five general classes: marine mammals, seabirds, marine reptiles, fish, and habitat. Marine mammals include whales, dolphins, porpoises, seals, sea lions, and dugongs. Seabirds are defined as those birds that rely on the marine environment for at least part of the year. Marine reptiles include sea turtles and sea snakes. Fish include both bony fish, those species traditionally referred to as “fish,” and cartilaginous fish, like sharks and rays. It is important to note that both bony and cartilaginous fish are often targets of fisheries as well as bycatch. Examples of PET species that serve as habitat include coral reefs, sponges, and marine plants. Impact on habitat was addressed in a previous Sustainable Fisheries Partnership report on benthic protected areas and will not be addressed in this report.
Fishery impacts on PET species are dictated by type of fishing gear used. There are three general methods of harvest: “filtering” the water with a net (either by allowing water and fish to move through a stationary net, or by pulling a net through the water); luring the target species in and capturing it (with a baited hook or a trap); or actively hunting for prey (such as spearfishing). Because hunting for specific prey items usually involves visual verification of a target, bycatch is not often an issue. But both the filtering and luring methods can result in bycatch, some more so than others.
With the multitude of anthropogenic threats facing PET species, it is important to minimize bycatch, or the impacts of bycatch, to the greatest extent practicable. It is not always possible to completely eliminate bycatch mortality, and it is not always necessary if the PET population is robust enough to withstand fishing mortality. But the opposite may also be true; if a population is depleted severely, or is naturally small or vulnerable to bycatch mortality because of its biological characteristics, fishing mortality may need to be eliminated completely.
There are three general approaches to bycatch reduction: avoid capture, allow escape, and reduce mortality. These techniques should generally be applied in that order. A fishery should first attempt to reduce the amount of overall bycatch by avoiding capture of PET species through changes in fishing practices, gear types, or fishing closures in certain areas or seasons. If capture does still occur, modification to the gear or fishing technique should be made that will allow the PET species to escape the fishing gear. If escape is not possible, efforts should be made to reduce the amount of mortality caused by the interaction and increase the chance of survival once released from the fishing gear. The fishing industry should always be deeply involved in the development of bycatch reduction methods because the economic consequences of these modifications and regulations can be severe.
Four case studies are presented to illustrate implementation of PET bycatch reduction techniques:
The US Atlantic shrimp fishery is required to use turtle excluder devices (TEDs) to allow sea turtles to escape from trawl nets. While very contentious and difficult to implement, this requirement has greatly reduced mortality of sea turtles and populations are showing signs of rebuilding. In addition, a US law prohibits import into the US of shrimp and shrimp products that were harvested in a manner that may adversely affect sea turtles. Adoption of TEDs was often the simplest method of achieving this goal and TEDs have been implemented in many places around the world, but not everywhere. The EU does not have a comparable law, thus provides a market for shrimp harvested without TEDs.
A pilot project in the Swedish Eastern Baltic cod fishery is experimenting with cod pots as an alternative to gillnets, which have bycatch of a critically endangered sub-population of harbor porpoise. Pots catch fewer though higher-quality fish than gillnets, and pot-caught cod may require a higher price in order for the gear to be profitable. Though still in an experimental phase and not yet adopted by the commercial fishery, the pots were included in a recent Marine Stewardship Council certification along with trawls and longlines, while gillnets failed the certification process.
On the west coast of the US, the California groundfish fishery is prohibited from bottom fishing in 4,300 square miles of Cowcod Conservation Areas to protect and rebuild the severely depleted cowcod stock. Bycatch mortality has decreased drastically and the cowcod stock has stabilized and is showing initial signs of recovery.
The Australia eastern tuna and billfish fishery has had to contend with bycatch of a variety of PET species, including sharks, sea turtles, and seabirds. Thus, this case study illustrates how even a fishery with a multitude of sustainability issues can commit to continuous improvement and move towards sustainability.
In the final section of this report, the lessons learned in these case studies are interpreted to provide a suggested list of best practices in developing PET bycatch avoidance and mitigation techniques. Representatives from the fishing industry must be included from the beginning and all stakeholders should have a clear understanding of why PET bycatch reduction is needed and how it can be achieved. Stakeholders must also ensure that there is a mechanism in place to measure impacts and outcomes. Additionally, monitoring and enforcement of bycatch mitigation measures is crucial. And finally, suppliers should recognize that while voluntary adoption of best practices by the fishing industry is a good start, in many cases legal mandates for mitigation measures are needed. While not a comprehensive lists of suggestions, these practices are a good basis from which to start.
This report concludes with practical actions for seafood suppliers and buyers. It may be necessary to develop procurement policies stating that source fisheries that impact PET species must work to minimize that impact. One such mechanism is participation in a fishery improvement project (FIP), but impacts can also be addressed on an ad hoc basis. The following is a list of practical actions that should be taken to implement PET bycatch mitigation.
1. Identify the source fisheries that are interacting with PET species and prioritize them based on risk – both risk to the PET species (e.g., severely depleted species) and risk to your business (e.g., high-profile PET species or fisheries or high purchase-volume fisheries).
2. Engage with the fishing industry to determine how PET bycatch occurs and enlist their participation in developing mitigation measures.
3. Support the formation of an interdisciplinary work group, including fishermen, scientists, managers, and conservationists. The work group should look to other similar fisheries around the world to obtain ideas of bycatch reduction techniques that have been tested and/or implemented.
4. Encourage the fishing industry to develop and voluntarily adopt changes to fishing practices or gear, potentially including creation of a Code of Good Practice.
5. Encourage the government and/or fishery management authority to implement new regulations mandating PET bycatch mitigation techniques.
6. Support and promote fisheries that successfully adopt PET bycatch techniques. Conversely, if fisheries are unwilling to reduce PET bycatch to the necessary levels, seafood suppliers and buyers may need to place a moratorium on purchases of those fishery products. In this, hopefully rare, case, suppliers and buyers should be clear to the industry and fishery managers why the moratorium on purchases has been implemented and what steps must be taken by the industry and government to lift that moratorium.
In many countries, impacts on PET species are limited and fisheries may be closed completely if the impacts on PET species become too substantial. In addition, consumers are becoming more aware of the impact of wild seafood harvest on the marine ecosystem and are demanding protection of not only charismatic species, but also those lesser-known species that are important to the health and function of the ecosystem. In order for the global seafood supply chain to secure their resources and markets, consideration must be given to reducing bycatch of PET species to the maximum extent practicable. Countless examples from around the world show that PET bycatch reduction is not only possible, but also practicable.