Experiment to Evaluate Gear Modification on Rates of Sea Turtle Bycatch in the Swordfish Longline Fishery in the Azores Phase 4

Authors
Bolton, A. and K. Bjorndal
Year
Journal/Publisher Name
Final Project Report submitted to the U.S. National Marine Fisheries Service. Archie Carr Center for Sea Turtle Research, University of Florida, Gainesville
Summary

Japanese tuna hook 3.6mm S/S caught significantly more loggerhead sea turtles than non-offset 16/0 and 18/0 circle hooks and caught more turtles in the throat than the circle hooks in the Azores longline swordfish and blue shark fishery. Non-offset 18/0 circle hooks caught fewer loggerhead sea turtles than non-offset 16/0 circle hooks in the Azores longline swordfish and blue shark fishery. There was no significant difference in the number of blue sharks caught on non-offset 16/0 and 18/0 circle hooks in the Azores longline swordfish and blue shark fishery.

Link
http://www.sefsc.noaa.gov/PDFdocs/CR_Bolten_Bjorndal_2005.pdf

Field Studies

Experiment to Evaluate Gear Modification on Rates of Sea Turtle Bycatch in the Swordfish Longline Fishery in the Azores Phase 4

Study Type
Field study in the wild
Location
Azores
Target catch
Swordfish and blue shark
Effect on bycatch species
Non-offset 16/0 and 18/0 circle hooks caught fewer turtles than Japanese tuna hook. Non-offset 18/0 circle hooks caught fewer turtles than non-offset 16/0
Effect on target catch
There was no significant difference in the number of blue sharks caught on non-offset 16/0 and 18/0 circle hooks .
Bycatch species
Caretta caretta (Loggerhead turtle)
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines