Unanswered Forum Topics

Fishing gear modifications to reduce elasmobranch mortality in pelagic and bottom longline fisheries off Northeast Brazil

Study Type
Field study in the wild
Location
Brazil
Target catch
Tuna (pelagic) sharks (bottom)
Effect on bycatch species
Rates of external hooking were significantly higher with circle hooks
Bycatch species
Elasmobranchs
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Fishing gear modifications to reduce elasmobranch mortality in pelagic and bottom longline fisheries off Northeast Brazil

Study Type
Field study in the wild
Location
Brazil
Target catch
Tuna (pelagic) sharks (bottom)
Effect on bycatch species
Rates of external hooking were significantly higher with circle hooks
Bycatch species
Elasmobranchs
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Fishing gear modifications to reduce elasmobranch mortality in pelagic and bottom longline fisheries off Northeast Brazil

Study Type
Field study in the wild
Location
Brazil
Target catch
Tuna (pelagic) sharks (bottom)
Effect on bycatch species
Rates of external hooking were significantly higher with circle hooks
Bycatch species
Elasmobranchs
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Circle hook effectiveness for the mitigation of sea turtle bycatch and capture of target species in a Brazilian pelagic longline fishery

Study Type
Field study in the wild
Location
South-western Atlantic Ocean
Target catch
Tuna, blue sharks, swordfish
Effect on bycatch species
De-hooking was decreased from 25% to 5.8% in loggerhead sea turtles when circle hooks were used.
Bycatch species
Caretta caretta (Loggerhead turtle)
Demochelys coriacea (Leatherback sea turtle)
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Circle hook effectiveness for the mitigation of sea turtle bycatch and capture of target species in a Brazilian pelagic longline fishery

Study Type
Field study in the wild
Location
South-western Atlantic Ocean
Target catch
Tuna, blue sharks, swordfish
Effect on bycatch species
De-hooking was decreased from 25% to 5.8% in loggerhead sea turtles when circle hooks were used.
Bycatch species
Caretta caretta (Loggerhead turtle)
Demochelys coriacea (Leatherback sea turtle)
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Circle hook effectiveness for the mitigation of sea turtle bycatch and capture of target species in a Brazilian pelagic longline fishery

Study Type
Field study in the wild
Location
South-western Atlantic Ocean
Target catch
Tuna, blue sharks, swordfish
Effect on bycatch species
De-hooking was decreased from 25% to 5.8% in loggerhead sea turtles when circle hooks were used.
Bycatch species
Caretta caretta (Loggerhead turtle)
Demochelys coriacea (Leatherback sea turtle)
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Circle hook effectiveness for the mitigation of sea turtle bycatch and capture of target species in a Brazilian pelagic longline fishery

Study Type
Field study in the wild
Location
South-western Atlantic Ocean
Target catch
Tuna, blue sharks, swordfish
Effect on bycatch species
De-hooking was decreased from 25% to 5.8% in loggerhead sea turtles when circle hooks were used.
Bycatch species
Caretta caretta (Loggerhead turtle)
Demochelys coriacea (Leatherback sea turtle)
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Development and observations of spiny dogfish Squalus acanthias reduction device in a raised footrope silver hake Merluccius bilinearis trawl

Study Type
Field study in the wild
Location
Massachusetts Bay
Target catch
Silver hake
Effect on bycatch species
There were no observed differences in the behavior of spiny dogfish between gear configurations or grate colors.
Bycatch species
Sharks
Reduction technique
Excluder devices
Fishing Gear
Trawls

Development and observations of spiny dogfish Squalus acanthias reduction device in a raised footrope silver hake Merluccius bilinearis trawl

Study Type
Field study in the wild
Location
Massachusetts Bay
Target catch
Silver hake
Effect on bycatch species
There were no observed differences in the behavior of spiny dogfish between gear configurations or grate colors.
Bycatch species
Sharks
Reduction technique
Excluder devices
Fishing Gear
Trawls

Development and observations of spiny dogfish Squalus acanthias reduction device in a raised footrope silver hake Merluccius bilinearis trawl

Study Type
Field study in the wild
Location
Massachusetts Bay
Target catch
Silver hake
Effect on bycatch species
There were no observed differences in the behavior of spiny dogfish between gear configurations or grate colors.
Bycatch species
Sharks
Reduction technique
Excluder devices
Fishing Gear
Trawls

Hawaii longline tuna fishery temporal trends in standardized catch rates and length distributions and effects on pelagic seamount ecosystems

Study Type
Field study in the wild
Location
Pacific
Target catch
Tuna
Effect on bycatch species
Reduced sea turtle interactions likely due to use of circle and not J hooks
Effect on target catch
All tuna species had higher catches rates when wider circle hooks were used. Shortfin spearfish and striped marlin catch rates were lower with circle hooks. No differences in average length between hook types.
Bycatch species
Sea Turtles
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Hawaii longline tuna fishery temporal trends in standardized catch rates and length distributions and effects on pelagic seamount ecosystems

Study Type
Field study in the wild
Location
Pacific
Target catch
Tuna
Effect on bycatch species
Reduced sea turtle interactions likely due to use of circle and not J hooks
Effect on target catch
All tuna species had higher catches rates when wider circle hooks were used. Shortfin spearfish and striped marlin catch rates were lower with circle hooks. No differences in average length between hook types.
Bycatch species
Sea Turtles
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

Hawaii longline tuna fishery temporal trends in standardized catch rates and length distributions and effects on pelagic seamount ecosystems

Study Type
Field study in the wild
Location
Pacific
Target catch
Tuna
Effect on bycatch species
Reduced sea turtle interactions likely due to use of circle and not J hooks
Effect on target catch
All tuna species had higher catches rates when wider circle hooks were used. Shortfin spearfish and striped marlin catch rates were lower with circle hooks. No differences in average length between hook types.
Bycatch species
Sea Turtles
Reduction technique
Circle hooks
Fishing Gear
Hooks-and-Lines

A simple technical measure to reduce bycatch and discard of skates and sharks in mixed-species bottom-trawl fisheries

Submitted by morgaac on

A study was conducted to determine the impact of removing the 'tickler' from in front of groundgear of trawls. The 'tickler' is a length of chain placed in front of the groundgear of trawl gear, which is supposed to increase catches of sharks and rays. Tests were conducted where the 'tickler' was removed and secondary nets (groundgear bags) were placed behind the groundgear to determine the amount and species of fish that escaped capture. The results indicated that removing the 'tickler' from in front of the groundgear reduced the capture of skates and sharks.

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