Shark Depredation and Unwanted Bycatch in Pelagic Longline

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Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries Pre-treated baits may be a less expensive option. Shark Defense conducted preliminary trials of the chemical’s effect on shark and target species CPUE in Bahamas demeral longline fishery, on captive yellowfin tuna by the Inter-American Tropical Tuna Commission, and on captive cobia (Rachycentron canadum) by the University of Miami. Results to date are promising (Eric Stround, personal communication, Shark Defense LLC, 3 April 2006). It is hypothesized that when the semiochemical is at a concentration > 0.1 ppm it will repel Carcharhiniform sharks without repelling bony fish (Eric Stround, personal communication, Shark Defense LLC, 3 April 2006). Shark Defense is also conducting preliminary trials of neodymiumiron-boride (Nd2Fe14B) magnets as a possible shark deterrent in longline gear (Eric Stround, personal communication, Shark Defense LLC, 3 April 2006). It is hypothesized that a 10 cm x 4 cm NdFeB magnet’s field would be effectively detected by sharks up to a 0.3 m range. Sharks possess an organ, Ampullae of Lorenzini, that is used to detect weak electrical fields at short ranges. Preliminary research conducted in 2005 on the effect of Nd2Fe14B magnets by the Inter- American Tropical Tuna Commission on captive yellowfin tuna and by the University of Miami on cobia indicates that the presence of the magnet versus a control produced no significant difference in feeding behavior (Eric Stround, personal communication, Shark Defense LLC, 3 April 2006). Preliminary research in a demersal longline fishery in the Bahamas is underway. A 2.5 cm x 2.5 cm Nd2Fe14B nickel-coated cylinder with a center bore costs about USD 300 for 100 magnets (Eric Stround, personal communication, Shark Defense LLC, 3 April 2006). A recent discovery by SharkDefense shows that electropositive metals (e.g. Neodymium, Praseodymium, early Lanthanide metals, Mischmetal, and Magnesium) may repel sharks (Eric Stround, personal communication, Shark Defense LLC, 9 February 2007). These metals, which are also present in rare earth magnets, may be responsible for some of the repellency effect seen with permanent magnets and present a more practical alternative to the magnets. These metals are not inherently magnetic (they are not ferromagnetic). A correlation has been found between standard oxidation potential of these metals and their behavioral response using immobilized sharks. An electrical shark avoidance device was tested in a coastal midwater trawl fishery in the Sea of Japan (Ishikawa Prefecture) in 2004 (Clarke, this volume). The purpose of the device was to deter predation by sharks on the cod end of the trawl during hauling. The device, mounted on the fishing vessel, emitted an electrical pulse into the waters in the immediate vicinity. It was believed by fishermen to be effective based on qualitative observations of sharks suddenly moving away from the cod end and the vessel once the electrical pulse was emitted (Clarke, this volume). The Shark Protective Ocean Device (POP) is a device designed to be worn by scuba-divers that emits an electrical field with a radius of 4-6 m to repel sharks from divers (www.elasmo-research.org). The device costs about USD 700. This technology theoretically could be modified to deter sharks from foraging on bait and catch on longline hooks. Acoustic deterrents may reduce shark-longline interactions, but have not been tested in longline fisheries for any shark species. 7.2. Hotspot Avoidance through Fleet Communication and Protected Areas Fleet communication programs and area and seasonal closures are management tools that can enable a longline fleet to avoid bycatch hotspots that can complement employment of other strategies to reduce shark bycatch and depredation. The distribution of sharks and other species groups such as seabirds, sea turtles and cetaceans, is often unpredictable, and may be spatially contagious or aggregated. Consequently, fleet communication systems may be employed by fishing industry to report near real-time observations of hotspots to enable a fishery to operate as a coordinated “One Fleet” to substantially reduce fleet-wide depredation and bycatch of sharks (Gilman et al. 2006c). In addition, fleet coordination of daily fishing positions and times, a current practice in many fleets, may minimize per vessel shark interaction levels relative to vessels that fish in isolation (Gilman et al., 2006c). Area and seasonal closures can also contribute to reducing sharklongline interactions. Establishing protected areas within a nation’s Exclusive Economic Zone is potentially an expedient method to reduce shark-longline interactions. However, establishing and managing high seas marine protected areas to protect sharks, which would require extensive and dynamic boundaries and extensive buffers, may not be a viable short-term solution. This is due in part to the extensive time anticipated to (i) resolve legal complications with international treaties, including creating legally binding mechanisms for multilateral designation and management of high seas protected areas; (ii) achieve international consensus and political will; (iii) provide requisite extensive resources for surveillance and enforcement, in part, to control illegal, unreported and unregulated fishing activities; and (iv) improve the scientific basis for designing high seas marine protected areas, which can be effective at reducing shark interactions only where the location and times of occurrence of shark hotspots are known and predictable (Gilman, 2001). However, establishing and managing a representative system of protected area networks on the high seas to contribute to the management of interactions between marine capture fisheries and highly migratory sensitive species groups, including sharks, may eventually be realized. Recent developments within the framework of the United Nations Convention on the Law of the Sea and associated conventions and by several Regional Fishery Management Organizations may make it possible in the near future to establish marine protected areas on the high seas that restrict fishing activities that are shown to threaten rare or fragile ecosystems or the habitat of depleted, threatened or endangered species and other forms of marine life. It is already possible to establish high seas marine protected areas for discrete areas by agreement by individual countries. However, there remains a need for an international framework with specific language to identify the criteria to establish a representative system of high seas marine protected area networks, and management and enforcement measures for the individual marine protected areas. Several regional fishery management organizations are updating their scope and legal mandate to include ecosystem-based management and biodiversity conservation under the auspices of the Fish Stocks Agreement. 30
Potential of Deterrents, Hotspot Avoidance and Incentive Instruments to Reduce Shark Interactions in Pelagic Longline Fisheries The Commission for the Conservation of Antarctic Marine Living Resources has made some preliminary progress towards establishing a system of marine protected areas in the Southern Ocean. Consequences of establishing a protected area need to be carefully considered, as resource use restrictions of a marine protected area may displace effort to adjacent and potentially more sensitive and valuable areas, where weaker management frameworks may be in place (Murray et al., 2000; Baum et al., 2003; Kotas et al., 2004). Also, measures adopted by regional fishery management organizations and other international bodies are only binding to parties to the Convention that established the organization, and will not control activities by non-party States. Thus, another consideration for employing high seas marine protected areas to manage problematic fisheries bycatch is that closing areas to fisheries only of party States could result in increased effort in this area by fleets from non-party States with fewer or no controls to manage bycatch, exacerbating the problem for which the MPA was established to address. International bodies have created marine protected areas on the high seas: The International Whaling Commission declared the Indian and Southern Oceans as no-take sanctuaries for whales, covering 30 percent of the world’s oceans mostly on the high seas. Conventions governing international shipping have designated large areas of the ocean that include high seas as Special Areas where stringent restrictions apply regarding discharges from ships. Furthermore, under the United Nations Convention on the Law of the Sea, the International Seabed Authority could protect areas from minerals extraction beyond national jurisdiction where there is a risk of harm to the marine environment (Kelleher, 1999). Recent developments within the framework of the United Nations Convention on the Law of the Sea and associated conventions may make it possible in the future to restrict fisheries activities on the high seas that are shown to undermine marine conservation (Kelleher, 1999). 7.3. Incentive Instruments Several incentive instruments can be instituted by industry, management authorities, and conservation groups to contribute to industry employment of methods to reduce shark bycatch and injury (Gilman et al., 2002). 7.3.1. National and local constraints National-level legal, regulatory, and policy-derived formal constraints, combined with an effective surveillance and enforcement program, can promote fishing industry compliance with laws, rules, and policies to minimize shark bycatch. For instance, restrictions on shark finning, wire trace and per trip shark retention are examples of regulatory constraints on pelagic longline fishery interactions with sharks. Time/are closures and mandatory use of avoidance techniques (e.g., proscribing a minimum depth for the setting of baited hooks through certain gear design specifications, using fish instead of squid for bait, prohibiting use of light sticks) are other examples of potential regulatory tools to manage shark bycatch and depredation (Hall et al., 2000; Gilman et al., 2005). Fishery management authorities could create a fee and exemption structure for shark bycatch, applicable to individual vessels or to an entire fleet, similar to a “polluter pays” system. Alternatively, the fee structure could provide a positive reward-based incentive, where a higher subsidy, lower permit or license fee, earlier start to the fishing season, or lower taxes apply, and a positive image is portrayed when a vessel or fleet meets standards for shark bycatch. The threat of a fishery closure if performance standards related to shark interactions are not met provides a strong incentive for industry compliance to minimize shark interactions. 7.3.2. Regional and international accords, regulations, and policies Multilateral treaties and accords that address shark interactions can obligate national governments to adopt enabling legislation to manage these interactions. Regional Fishery Management Organizations can adopt regulations and policies to manage interactions between fisheries and sensitive species for compliance by member nations. Multilateral bodies can adopt advisory policies to encourage fishing nations to sustainably manage shark-longline interactions. Recent international initiatives addressing shark finning are summarized in the Introduction. 7.3.3. Eco-labeling Consumer demand can alter industry behavior. In 2005 the Committee on Fisheries of the Food and Agriculture Organization of the United Nations adopted Guidelines for the Ecolabelling of Fish and Fishery Products from Marine Capture Fisheries. The new guidelines provide guidance to governments and organizations that already maintain, or are considering establishing, labeling schemes for certifying and promoting labels for fish and fishery products from well-managed marine capture fisheries. A longline fishing industry can pursue certification or accreditation from an eco-labeling certification program, in part, to demonstrate the employment of best practices to reduce shark bycatch and discards. The incentives to industry are market-based, to increase demand for and value of their products, and social, to receive recognition from the public for complying with accepted norms (Wessells et al., 1999). Eco-labeling can serve as an effective marketing tool for a fishing industry, when properly managed. For instance, certification under an eco-labeling scheme can be used as a marketing tool to develop and market an image and product differentiation, through advertising, sales promotion, public relations, direct marketing, and media coverage. A company can differentiate their products from other seafood as originating from a fishery that follows internationally accepted practices to ensure environmental sustainability. This is a form of cause-related marketing, a proven means to promote recognition and develop a positive company image and reputation. 7.3.4. Industry and market self-policing A longline industry can create a program where information on individual vessel shark bycatch levels and compliance with relevant regulations is made available to the entire industry. This self-policing program uses peer pressure within the fishing industry to criticize ‘bad actors’ and publicly acknowledge those fishers who are operating in a responsible manner. For example, the North Pacific Longline Association initiated a seabird bycatch report card system among its members in 2000 (Fitzgerald et al. 2004). Also, there are market pressures to avoid bringing in target species damaged by sharks. 31
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Page 9 and 10: Contents Summary and Conclusions 1
Page 11 and 12: Contents Appendix 3. Fiji Pelagic L
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Page 19 and 20: Chapter 1 Introduction and Methods
Page 21 and 22: Introduction and Methods 1.2. Metho
Page 23 and 24: Fishing Gear and Operational Charac
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Page 29 and 30: Chapter 4 National and Internationa
Page 31 and 32: National and International Measures
Page 33 and 34: Economic, Practical, Ecological and
Page 35 and 36: Economic, Practical, Ecological and
Page 37 and 38: Chapter 6 Industry Attitudes and Pr
Page 39 and 40: Industry Attitudes and Practices Lo
Page 41 and 42: Industry Attitudes and Practices Fi
Page 43: Chapter 7 Potential of Deterrents,
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Page 49: References Neves dos Santos, M., Ga
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Appendix 5 Japan Pelagic Longline F
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Appendix 6 Peru Artisanal Mahimahi
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South Africa Pelagic Longline Tuna
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Appendix 8 USA Hawaii-based Pelagic
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Shark Depredation and Unwanted Bycatch in Pelagic Longline

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