Shark Depredation and Unwanted Bycatch in Pelagic Longline

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Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries and threshers) for which there is sufficient value for their meat. Furthermore, many operators in this fishery will only retain a shark that is of a marketable species if it is dead or dying when hauled to the vessel, which can be safely and relatively easily landed. The South Africa longline tuna and swordfish fishery is subject to a shark landing limit of 10% of the total swordfish and tuna catch. This theoretically has been economically detrimental to the industry. From 1998-2005, the total number of caught sharks was 18% of the total number of caught swordfish and tunas. Thus, vessels would need to discard about 44% of their caught sharks to comply with the shark limit. Because only about 18% of caught blue sharks and 10% of makos have been observed to be released alive in this fishery, and the literature demonstrates that a much larger proportion of these shark species (>85%) are likely alive when hauled to the vessel (e.g., Beerkircher et al., 2002), it is likely that fishers are not complying with this measure. A prohibition on the use of a wire trace in the Australian longline tuna and billfish fishery and South Africa longline tuna and swordfish fishery has likely resulted in an increased economic cost from shark interactions as this has likely caused an increase in the loss of terminal tackle to sharks. A substantially larger number of hooks, bait and line are likely now bitten off of branch lines compared to when wire trace was used. However, fishers generally do not consider this to be a large concern. It is not known how the injury to sharks from retaining hook and trailing monofilament line affects their survival prospects. This is a research priority. This may be an improvement to their previous fate when caught on lines with wire trace when they would soak on the gear for hours, be gaffed and hauled onboard the vessel and then have hooks removed by cutting with a knife or pulled out by force. Available but limited information indicates that a large proportion of sharks caught in longline gear that are released after removal of the hook will survive (Section 6.2.4; U.S. National Marine Fisheries Service, 2005). In fisheries where a large proportion of caught sharks is killed either for retention or discarding, prohibiting the use of wire leaders will almost definitely reduce shark fishing mortality. Prohibiting wire leaders may exacerbate seabird bycatch problems: Fishers will be less likely to attach weights close to hooks on branch lines lacking a wire leader due to safety concerns, thus, reducing the baited hook sink rate, and increasing seabird catch rates. Shark fisheries in Peru are regulated by the Ministry of Fishery through size limits for certain elasmobranch species (Diario Oficial El Peruano, 2001). However, there is little enforcement of these regulations and few fishers are aware that the regulations exist (Alfaro and Mangel, 2002). Of the few interviewed fishers who reported that they were aware of the regulations (5%), all report that they still retain sharks that are under the minimum size limit. 4.2. International Initiatives Addressing Shark Finning There have been several recent international initiatives addressing shark finning. Fisheries subject to restrictions on finning sharks are expected to have a high incentive to avoid shark interactions. A summary of international initiatives related to shark finning follows. • Food and Agriculture Organization of the United Nations: In 1999 the Food and Agriculture Organization of the United Nations (FAO) endorsed the International Plan of Action for the Conservation and Management of Sharks. This is a non-legally binding voluntary initiative calling on States to ensure the conservation and management of sharks, including by minimizing waste and discards from shark catches such as through requiring the retention of sharks from which fins are removed (FAO, 1999b). • International Commission for the Conservation of Atlantic Tunas: In November 2004, the International Commission for the Conservation of Atlantic Tunas (ICCAT) adopted with consensus a binding measure requiring full utilization of shark catches (fishers must retain all parts of the shark except the head, guts, and skins to the point of first landing) and prohibiting vessels in ICCAT fisheries from retaining on board, transshipping, or landing any shark fins that are taken in contravention of the measure. Countries must ensure that their vessels retain fins totaling no more than 5 percent of the weight of sharks onboard up to the first point of landing, or otherwise must ensure compliance with the ratio through certification, monitoring, or other means. • United Nations General Assembly: In November 2004, the United Nations General Assembly adopted by consensus a resolution on Oceans and the Law of the Sea Sustainable Fisheries, including through the 1995 Agreement, which includes a provision that discourages shark finning, calls for implementation of the FAO International Plan of Action on sharks, and invites FAO to study the impact on shark populations of shark catches from directed and non-directed fisheries. • International Union for Conservation of Nature and Natural Resources: In November 2004, the International Union for Conservation of Nature and Natural Resources (IUCN) adopted a recommendation urging all States to ban shark finning and require shark fins to be landed attached to their bodies. • Inter-American Tropical Tuna Commission: In June 2005, the Inter-American Tropical Tuna Commission (IATTC) adopted a Resolution on the Conservation of Sharks Caught in Association with Fisheries in the Eastern Pacific Ocean, which bans shark finning and mandates the collection of information and advice on stock status of shark species. The resolution also requires members to comply with the FAO International Plan of Action on sharks and take measures to require that their fishers fully utilize any retained sharks. • North Atlantic Fisheries Organization: In September 2005, the North Atlantic Fisheries Organization (NAFO) adopted a resolution modeled after the IATTC and ICCAT measures, banning shark finning in all NAFO-managed fisheries, and mandated the collection of information on shark catches. 16
National and International Measures 4.3. Conclusions on Data Collection and Management Frameworks Most national fishery management authorities of the 12 fisheries included in this study demonstrate a low priority for monitoring and managing chondrichthyan fishes, consistent with the results of a global review by Shotton (1999). Few regional fishery management organizations are using fishery-dependent data to conduct shark stock assessments (only the International Commission for the Conservation of Atlantic Tunas, for blue and shortfin mako sharks in the North and South Atlantic (Anonymous, 2005)). Sustainable management of chondrichthyan populations is hampered by this general lack of fishery-dependent data and management measures for sharks (Musick, 2005). The expanding exploitation of sharks, for their fins as well as meat, largely in the absence of management frameworks and the lack of reliable fishery-dependent data and fundamental understanding of the biology of most shark species’ warrant concern for the health of shark populations as well as ecosystem-level effects from population declines. Approaches to sustainably manage cartilaginous fishes will necessarily differ from traditional fishery management methods for teleosts due to cartilaginous fishes’ relatively low reproductive potential (Stevens et al., 2005). There are few fisheries with measures to manage shark catch levels. Clarke (this volume) and Mangel and Alfaro-Shigueto (this volume) identify growing markets for shark meat at several ports worldwide (Chapter 5, Section 5.1). This trend toward more utilization of shark meat may be beneficial in the short term in that fully utilized sharks are more likely to be reported in logbooks and landings statistics than are the retention and landing of just shark fins. However, if the shark meat market continues to grow, this could increase shark catch rates and fishing mortality. Existing finning prohibitions do not manage the number of sharks that are killed. Thus, to prepare for a possible increase in demand for shark meat fishery management authorities are encouraged to institute data collection, monitoring and precautionary management measures to ensure that shark catches are sustainable. Table 4.1. Legal framework that influence practices and attitudes towards shark bycatch and depredation in six pelagic longline fisheries (Commonwealth of Australia, 1991; Diario Oficial El Peruano, 2001; Council of the European Union, 2003; U.S. National Marine Fisheries Service, 2002, 2005). Legal Constraints 1 Pelagic Longline Fisheries by Flag State Retention of Fins Requires Retention of Corresponding Carcass 2 Shark Retention Prohibit Wire Trace Prohibit Retention Limit 3 of Specified Shark Species Size Limit Australia tuna and billfish X X X X Italy Mediterranean industrial swordfish X Peru artisanal mahi mahi and shark X South Africa tuna and swordfish X X X USA - Hawaii tuna USA - Hawaii swordfish X X 1 Japan and Fiji distant water longline tuna vessels may comply with voluntary measures adopted by Regional Fishery Management Organizations, and vessels operating in EEZs of other nations through foreign license access agreements may be required to comply with restrictions on shark catch, retention and use under these access agreements. 2 U.S.A., Italy (European Union), and South Africa require the total weight of retained shark fins to be < 5% of the total dressed ‘live’ weight of shark carcasses (South Africa Marine Living Resource Act of 1998; Council of the European Union, 2003; U.S. National Marine Fisheries Service, 2002, 2005) 3 . Australia requires fins to be attached to the shark carcass when landed (Commonwealth of Australia, 1991). 3 Australia has a 20 shark carcass per trip retention limit for longline tuna and billfish fisheries (Commonwealth of Australia, 1991). South Africa has a shark landing limit of 10% of the total swordfish and tuna catch (Petersen and Goren, this volume) 3 The Council of the European Union (2003) Regulation No. 1185, adopted in conjunction with the European Parliament, is legally binding in all Member States of the European Union, without any further action needed on the part of the national authorities, i.e., there is no need for Member States to adopt national enabling instruments to make the measure legally binding in their fisheries. In September 2006, the European Parliament passed a Resolution (a non-binding instrument) on the application of Regulation 1185/2003, which calls on the Commission of the European Union to present to the European Parliament and the Council no later than 30 June 2007 a Community Plan of Action for the conservation of sharks and seabirds, and to review the appropriateness of the Regulation’s shark fin to carcass dressed weight ratio (European Parliament, 2006). 17
Page 3 and 4: Shark Depredation and Unwanted Byca
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Page 9 and 10: Contents Summary and Conclusions 1
Page 11 and 12: Contents Appendix 3. Fiji Pelagic L
Page 13: Contents Appendix 8. USA Hawaii Lon
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
Page 25 and 26: Fishing Gear and Operational Charac
Page 27 and 28: Shark Catch Rates and Disposition T
Page 29: Chapter 4 National and Internationa
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
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Page 41 and 42: Industry Attitudes and Practices Fi
Page 43 and 44: Chapter 7 Potential of Deterrents,
Page 45 and 46: Potential of Deterrents, Hotspot Av
Page 47 and 48: References Campana, S.E., L. Marks,
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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Peru Artisanal Mahimahi And Shark L
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Appendix 8 USA Hawaii-based Pelagic
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Appendix 9 USA Atlantic, Gulf of Me
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