Shark Depredation and Unwanted Bycatch in Pelagic Longline

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Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries Table A2.4. Swordfish capture, effort and yield of the industrial and artisanal swordfish fleet (Barria et al., 2006). Capture (kg) Effort (# hooks) Yield (g/hook) Month 2004 2005 2004 2005 2004 2005 Jan 793 980 809 Feb 12838 20998 611 Mar 63599 138740 458 Apr 88164 147611 247890 234352 356 630 Fig. A2.6. Growth of the longline fleet in Chilean waters from 1970 to 1995 (FAO, 2006). May 143354 147522 325025 324981 441 454 Jun 74609 136215 206336 253424 362 537 Jul 128120 207226 280805 365073 456 568 Aug 94786 158662 354098 359530 268 441 Sep 126771 132303 351787 330693 360 400 Oct 60926 148784 240473 239527 253 621 Nov 75683 109411 171665 234675 441 466 Fig. A2.7. Total shark exports in quantity and value, 1976-2005 (FAO, 2006). Dec 94873 47082 291911 174808 325 269 Total % variation 887287 1312046 47.9 2469990 2677781 8.4 359 490 36.4 Table A2.5. Catch, revenue and CPUE of swordfish and sharks for the industrial swordfish fishery, 2005 (Barria et al., 2006). Species Catch (kg) Revenue ($1000US) CPUE (kg/hook) Swordfish 2,193,129 11404.3 1.01 Blue sharks 535,721 482.1 0.25 Mako sharks 247,662 598.1 0.11 A2.7. Shark Market and Management Framework There has been a substantial increase in longline vessel operations in Chile from 1986 to 1995 (Fig. A2.6). During this same period, growth in shark exports was much more variable (Fig. A2.7). Fresh shark products are directed mainly to the domestic market, while fins are exported (Vanuccini, 1999). Captured skates are destined almost entirely for export to Asian markets (Acuña and Lamilla, 2004). Skate wings are exported frozen. Shark species such as blues, makos and smoothounds are mainly exported as frozen headed-and-gutted and as steaks. Fins are exported dried (Vanuccini, 1999; Table A2.6). Prices are variable and there are large differences between dried shark fin and chilled and frozen products (Table A2.7). A2.8. Economic, Social, and Ecological Effects, Including Effects on Fishing Practices, from Regulations Governing Shark Interactions From the twenty-two fishermen interviewed, 7 were based in Arica, 12 in Iquique and 3 in Valparaiso. Almost all (95.5%) interviewed fishermen report that they always retain sharks during the mahi mahi and swordfish season. Regularly, blue and mako sharks are caught and the whole body and fins are retained. However, sometimes blue sharks are only finned and the bodies are discarded. The whole crew and boat owner receive the revenue from the sale of fins and meat. Meat of blue sharks is sold for approximately $0.3-1.5 and makos for 60
Chile Artisanal Mahimahi and Shark Longline Fishery and Longline Swordfish Fishery Table A2.6. Exports of shark and ray products from 1993 to 1997 (Vanuccini, 1999). 1993 1994 1995 1996 1997 (Jan-Nov) Species $ Tons $ Tons $ Tons $ Tons $ Tons Rays 2,136 1,420 4,343 2,371 5,420 2,948 4,494 2,278 4,347 1,954 Makos 804 240 696 268 1,011 199 634 121 1,147 159 Blues 254 42 581 136 162 20 215 41 69 27 Smoothhounds 29 16 23 10 57 27 33 15 -- -- Shark (unspecified) 332 42 371 61 358 65 456 46 544 38 Total 3,555 1,760 6,014 2,846 7,008 3,259 5,832 2,501 6,107 2,178 $1.5-3.8 per kilo. Revenue from fins ranges up to $7.4 per kilo. Mako fins are more valued than those of blue sharks. Almost two thirds (64%) of respondents replied that income from sharks has not changed throughout the years. Two of three swordfish fishermen replied that in the past, revenue from fins was retained by the vessel owner only and one replied that revenue from the sale of sharks is retained by the owner company. Revenue from the sale of cartilage, jaws or liver oil is retained by the whole crew and boat owner. Almost half (47.4%) of mahi mahi fishermen mentioned that there are no regulations for sharks in their country, and more than half (52.6%) mentioned that in the event that such regulations existed, they have not affected the way they deal with sharks. All swordfish fishermen reported that they were not aware of any regulations concerning sharks. For most of the fishermen interviewed (95.5%), revenue from catching sharks exceeded the cost from shark depredation and loss and damage to gear (average damage cost per mahi mahi set was $18.5, per swordfish set it was 50-100 hooks and/or branch lines). Only one swordfish fisherman (4.5%) mentioned that revenue from sharks does not exceed the cost of shark depredation and damage to gear. Most fishermen change their fishing methods and gear during the mahi mahi season. These changes – such as using nylon monofilament, using giant squids for bait, setting hooks shallower than in shark season, and fishing in areas closer to shore - have the indirect effect of reducing shark captures. The effect is unintentional because the main objective of the changes to fishing methods and gear is to increase mahi mahi captures, not necessarily to reduce the capture of sharks. However, some mahi mahi fishermen indicated they would use wire leaders to avoid gear loss. Wire leaders were said to be as effective as nylon monofilament on branch lines. Fishing for mahi mahi during summer is more profitable because fishing areas are closer to shore and the amounts of mahi mahi are considerably higher than during the shark season. Table A2.7. Average FOB prices for chondrichthyan products during the last six years (Vanuccini, 1999). Species Product $/Ton Destination Mako Frozen 1,867 Spain 1,886 Italy 2,364 USA Chilled 2,661 USA Dried fins 37,095 Far East Shark – unspecified Frozen 2,567 Germany 2,708 Spain Chilled 2,255 USA Dried fins 37,731 Far East Blue Frozen 792 Netherlands 541 Germany 1,300 Spain Dried fins 35,062 Asia Smoothhound Frozen 2,785 New Zealand 1,329 France 1,065 Spain Ray Frozen wings 1,913 Republic of Korea 1,856 France 1 398 Spain 61
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Shark Depredation and Unwanted Byca
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Contents Summary and Conclusions 1
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Contents Appendix 3. Fiji Pelagic L
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Contents Appendix 8. USA Hawaii Lon
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Page 19 and 20:
Chapter 1 Introduction and Methods
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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: 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
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Peru Artisanal Mahimahi And Shark L
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Appendix 7 South Africa Pelagic Lon
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South Africa Pelagic Longline Tuna
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Appendix 8 USA Hawaii-based Pelagic
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USA Hawaii-based Pelagic Longline S
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Appendix 9 USA Atlantic, Gulf of Me
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USA Atlantic, Gulf of Mexico and Ca
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Shark Depredation and Unwanted Bycatch in Pelagic Longline

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