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Geographical distribution of the US Pelagic Longline fishery

Western Atlantic Pelagic Longline Sea Turtle Mitigation Research John Watson, Dan Foster, Sheryan Epperly, Arvind Shah. Geographical distribution of the US Pelagic Longline fishery. Courtesy of Mauricio Ortiz. 2001 Experiment. Blue-dyed Squid bait – no significant effect

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Geographical distribution of the US Pelagic Longline fishery

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  1. Western Atlantic Pelagic Longline Sea Turtle Mitigation ResearchJohn Watson, Dan Foster, Sheryan Epperly, Arvind Shah

  2. Geographical distribution of the US Pelagic Longline fishery Courtesy of Mauricio Ortiz

  3. 2001 Experiment • Blue-dyed Squid bait – no significant effect • Move branch line 20 fathoms away from buoy no significant effect for Loggerhead turtles (Caretta caretta) increased catch of Leatherback turtles (Dermochelys coricea)

  4. 2002 Atlantic Experiments • 18/0 circle hooks • Mackerel bait

  5. Control and Experimental Hook Designs 1 ½” 2 1/4” 2 1/4” 9/0 J Hook (Control) 18/0 Circle Hook 10° Offset 18/0 Circle Hook 0° Offset (Squid and Mackerel Bait) (Squid Bait Only)

  6. Loggerhead Turtles Catch per 1000 hooks Circle Hook Squid Bait J Hook Mackerel Bait Circle Hook Mackerel Bait J Hook Squid Bait

  7. Leatherback Turtles Catch per 1000 hooks Circle Hook Squid Bait J Hook Mackerel Bait Circle Hook Mackerel Bait J Hook Squid Bait

  8. Swordfish Kilogramsper 1000 hooks J Hook Squid Bait Circle Hook Squid Bait J Hook Mackerel Bait Circle Hook Mackerel Bait

  9. Bigeye Tuna Kilogramsper 1000 hooks J Hook Squid Bait Circle Hook Squid Bait J Hook Mackerel Bait Circle Hook Mackerel Bait

  10. N=97 N=157

  11. N=84 N=11

  12. Effect of Hook Width on Ingestion of Hooks by Loggerhead Turtles (40-60 cm Length) Percent n=21 n=24 n=40 n=20 Hook Width

  13. N=88 N=40

  14. A EQUIPMENT FOR TURTLES NOT BOATED D DIP NET LaForce Line Cutter Epperly Biopsy Pole ARC Dehooker MOUTH OPENERS AND GAGS PVC Splice Couplings Bolt Cutters Rope Nylabones Avian Speculum Needle nose Pliers Lanyard Canine Mouth Gags Wooden Brush Handle Mono Cutters SHORT HANDLED DEHOOKERS B ARC E PVC splice couplings Flip Stick or “J” Dehooker C Avian speculum

  15. Additional Research • Sea Turtle Post Hooking Survival Pilot Study – Sheryan Epperly, Alan Bolten, Eric Prince, Chris Sasso, and Carlos Rivero. • Real Time Sea Turtle Satellite Telemetry Stephen Morreale and Cheryl Ryder Full report online at: http://www.mslabs.noaa.gov/mslabs/docs/ watson2.pdf

  16. 2003 Atlantic Experiments • 18/0 circle hooks Mackerel bait • 20/0 circle hooks Mackerel bait • 10/0 Japanese tuna hooks • 11/0 Modified J Hook • Hook timers and time depth recorders • Turtle survival studies

  17. ACKNOWLEDGMENTS • Captains, Crews, Owners, and Managers Participating in the Experiments • NOAA Fisheries Observers • ARC • Lindgren Pittman • Charlie Bergmann, Myrto Argyropoulou, Dennis Lee, Cheryl Brown, Larry Beerkircher, David Bernhart, Ron Rinaldo, Nick Hopkins, Lionel Laforce

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