Shark Depredation and Unwanted Bycatch in Pelagic Longline

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Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries Table A2.2. Fishing gear characteristics of the Chilean longline fishery (from surveys and Barria et al., 2006). Gear Characteristic Artisanal Mahi Mahi Spanish System Industrial swordfish American System Mainline material Mainline length Multifilament 4-5mm Ø 1500-2000 fathoms (2.7–3.7 km) Polypropylene Multifilament 6mm Ø 45 nautical miles (83 km) Monofilament 3.5mm Ø 35-55 nautical miles (64-101 km) Mainline deployment Superficial Mid-water Mid-water Distance between buoys 18-36 m (10-20 fm) 4.5 km varies Distance from buoy to mainline (float line length) NA 10 fathoms 10 fathoms Average branch line length 9.1 m (5 fm) 8.2 m (4.5 fm) 16.5 m (9 fm) Branch line material Monofilament polypropylene Monofilament 20mm Ø Wire trace or leader on branch lines Sometimes Yes or no Yes Number of hooks between buoys 1 110 220-250 Average maximum depth of hooks when set 6-8 fathoms 70m 70m Average maximum depth of mainline when set Superficial 50m 50m Mainline sink rate No information No information 90 m in 16 seconds Timing of set, soak, and haul Set: 7 AM (for 2-6 h) Soak: surveying the line several times a day Haul: 4 to 5 PM (for 3-4 h) Set: 6-8 PM (for 4 h) Soak: 20h Haul: 8AM (for 8 h) Set: 6PM (for 4 h) Soak: 8h Haul: 8AM (for 6 h) Lightstick use No Plastic polymer chemical or battery Number of hooks per set 100-350 1500 1200-2000 Hook setting interval No information No information 8-16 seconds Radio beacons No Yes Yes Hook type J 0,1,2,3 (10 o offset) J17 Ancora (no offset) J18 Ancora (no offset or 10 o offset) Weight size and location NA 60 g. at connection of mainline with float line Clip size and type NA 350S 350S J Mustad 9 (10 o offset) 80 g. at connection of mainline with float line 65-75 g. swivel at top of leader Bait type Mackerel and sardine Squid or mackerel Squid and mackerel Number of crew 2-3 12-15 8-10 Vessel Monitoring System No No No Table A2.3. Catch per unit effort of sharks of the artisanal shark fleet, 2003-2005 (Barria et al., 2006). Yield (g/hook) 2003 2004 2005 Month Mako Blue Total Mako Blue Total Mako Blue Total Jan 194.3 22.7 217.0 245.6 8.5 254.1 314.6 9.5 324.1 Feb 265.2 22.5 287.7 401.3 9.1 410.5 301.8 8.1 309.9 Mar 382.2 47.8 430.0 236.5 17.3 253.8 269.1 55.8 325.0 Apr 281.3 58.8 340.1 290.6 38.9 329.5 232.6 69.1 301.7 May 154.2 28.1 182.3 249.4 35.0 284.4 261.8 85.9 347.7 Jun 160.3 57.1 217.5 168.7 31.7 200.4 85.4 68.8 154.2 Jul 27.5 11.7 39.3 78.9 82.6 161.4 74.2 37.0 111.3 Aug 52.9 29.6 82.4 75.6 97.5 173.1 91.1 55.8 146.9 Sep 141.5 50.6 192.1 119.0 62.2 181.2 45.8 119.1 164.9 Oct 172.7 78.1 250.8 183.9 49.5 233.5 58.9 147.6 206.5 Nov 188.6 37.5 226.2 283.5 40.8 324.3 295.5 71.9 367.5 Dec 208.9 15.5 224.3 224.0 14.1 238.1 160.4 25.6 186.0 Total 216.9 37.5 254.4 249.8 26.9 276.7 235.9 41.8 277.7 58
Chile Artisanal Mahimahi and Shark Longline Fishery and Longline Swordfish Fishery Fig. A2.4. Diagram of longline gear using the Spanish System. Fig. A2.5. Diagram of longline gear using the American System. 59
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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
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: 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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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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