Shark Depredation and Unwanted Bycatch in Pelagic Longline

More documents

Recommendations

Info

Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries U.S. National Marine Fisheries Service. 2002. Fisheries off West Coast States and in the Western Pacific; Atlantic Highly Migratory Species; Fisheries of the Northeastern United States; Implementation of the Shark Finning Prohibition Act. Federal Register 67(28): 6194-6202. U.S. National Marine Fisheries Service. 2001. Endangered Species Act Section 7 Consultation Biological Opinion: Authorization of Pelagic Fisheries under the Fishery Management Plan for the Pelagic Fisheries of the Western Pacific Region. Watson, J., Foster, D., Epperly, S., Shah, A. 2005. Fishing methods to reduce sea turtle mortality associated with pelagic longlines. Canadian Journal of Fisheries and Aquatic Sciences 62. Western Pacific Regional Fishery Management Council. 2005a. Pelagic Fisheries of the Western Pacific Region. 2004 Annual Report. Honolulu, HI, USA. Western Pacific Regional Fishery Management Council. 2005b. Fishery Ecosystem Plan for Pacific Pelagic Fisheries of the Western Pacific Region. Western Pacific Regional Fishery Management Council, Honolulu, HI, USA, 215 pp. Western Pacific Regional Fishery Management Council. 2003. Managing Marine Fisheries of the U.S. Pacific Islands. Past, Present, and Future. Prepared by E. Gilman, ELG Environmental Services. WPFMC, Honolulu, HI, USA. 25 pp. Western Pacific Fishery Management Council. 132
Appendix 9 USA Atlantic, Gulf of Mexico and Caribbean Pelagic Longline Swordfish and Tuna Fisheries: Industry Practices and Attitudes towards Shark Depredation and Unwanted Bycatch John W. Mandelman and Tim B. Werner, New England Aquarium, jmandelman@neaq.org, twerner@neaq.org A9.1. Introduction It is widely held that the incidental capture of sharks in fisheries targeting alternative species represents a massive challenge in the proper management of this group (Figs. A9.1 and A9.2) (Barker and Schluessel, 2004). Akin to the outcome in high-seas commercial fisheries around the globe, sharks compose the highest percentage of bycatch in the U.S. Atlantic PLL (PLL) fishery for swordfish, tunas and tuna-like species (Beerkircher et al., 2002). Although rarely targeted in U.S. domestic PLL operations, sharks and rays constituted 25% of the overall catch in this fishery between 1992 and 2003 according to observer data (Abercrombie et al., 2005). If accounting for the other foreign fleets pelagic longlining in Atlantic waters, it has been estimated that the extent of shark bycatch by this capture method is considerably high, rivaling both the Indian and Pacific in terms of the number of individuals and overall shark biomass taken (Bonfil, 1994). Sharks are also among those responsible for inflicting damage (depredation) to baits, gear, and hooked targeted catch prior to haul-back in this fishery (Hoey and Moore, 1999). The species most commonly encountered in PLL operations are a variety of carcharhinids, and to a lesser extent, lamnid sharks. As several of these species are either prohibited from being landed or lack appreciable commercial value, discard rates are chronically high. For these reasons, interactions with sharks in the domestic PLL fishery are presumed as a relative nuisance; encumbering commercial operations for tuna and swordfish and afflicting fishermen with considerable costs through losses of and damage to gear, target catch (via depredation) and time. At the same time, physiological stress and physical trauma imposed during capture and handling can compromise the ultimate survival of discarded shark bycatch (Bonfil, 1994; Berkeley and Campos, 1988). If coupled with directed landings, discard mortality can elevate total fishing mortality (F) and imperil shark populations around the globe (Musick et al., 2000). The control of unintended shark Fig. A9.1. Longline captured Isursus oxyrinchus (shortfin mako shark), just prior to boarding. (Photo courtesy of Greg Skomal, Massachusets Division of Marine Fisheries, USA.) Fig. A9.2. Longline captured Prionance glauca (blue shark), just after boarding. (Photo courtesy of Greg Skomal, Massachusets Division of Marine Fisheries, USA.) interactions is thus important not only for the operations of the longline fishing industry, but the health of interacting shark populations. Importantly, bycatch issues have been the basis of several regulatory measures imposed upon the Atlantic PLL fleet. It is therefore clear that mitigating the extent of incidental takes in this fishery, inclu-ding those with sharks, will behoove industry, management and conservation communities alike. In the following report, we address the estimated extent of shark bycatch, the species composition of this catch, and to a much lesser extent, shark depredation in the PLL fishery of the Atlantic, Caribbean and Gulf of Mexico (GOM). We also present ongoing research and potential strategies regarding the attenuation of shark interactions in this fishery. In doing so, several important factors regarding the data sources must first be addressed. 133
Page 3 and 4:
Shark Depredation and Unwanted Byca
Page 5:
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 16 and 17:
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 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 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
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97: Shark Depredation and Unwanted Byca
Page 99 and 100: Appendix 5 Japan Pelagic Longline F
Page 101 and 102: Japan Pelagic Longline Fisheries Fi
Page 103 and 104: Japan Pelagic Longline Fisheries mo
Page 105 and 106: Japan Pelagic Longline Fisheries Ta
Page 107 and 108: Japan Pelagic Longline Fisheries is
Page 109 and 110: Japan Pelagic Longline Fisheries ta
Page 111 and 112: Japan Pelagic Longline Fisheries In
Page 113 and 114: Japan Pelagic Longline Fisheries A5
Page 115 and 116: Appendix 6 Peru Artisanal Mahimahi
Page 117 and 118: Peru Artisanal Mahimahi And Shark L
Page 127 and 128: Appendix 7 South Africa Pelagic Lon
Page 129 and 130: South Africa Pelagic Longline Tuna
Page 135 and 136: Appendix 8 USA Hawaii-based Pelagic
Page 137 and 138: USA Hawaii-based Pelagic Longline S
Page 145: USA Hawaii-based Pelagic Longline S
Page 149 and 150: USA Atlantic, Gulf of Mexico and Ca
show all

Shark Depredation and Unwanted Bycatch in Pelagic Longline

Create successful ePaper yourself

Delete template?

Save as template?