Unanswered Forum Topics

Integrated weight longlines with paired streamer lines - best practice to prevent seabird bycatch in demersal longline

Study Type
Field study in the wild
Location
Bering Sea
Target catch
Pacific cod
Effect on bycatch species
Integrated weight longlines paired with streamer lines eliminated surface foraging and shearwater catch by 97%; integrated weigh longlines reduced surface forager catch rates by 91% and unweighted longlines with paired streamer by 98%
Effect on target catch
Target catch rates were not affected
Bycatch species
Seabirds
Reduction technique
Bird-scaring devices
Sub-surface bait setting
Fishing Gear
Hooks-and-Lines

Integrated weight longlines with paired streamer lines - best practice to prevent seabird bycatch in demersal longline

Study Type
Field study in the wild
Location
Bering Sea
Target catch
Pacific cod
Effect on bycatch species
Integrated weight longlines paired with streamer lines eliminated surface foraging and shearwater catch by 97%; integrated weigh longlines reduced surface forager catch rates by 91% and unweighted longlines with paired streamer by 98%
Effect on target catch
Target catch rates were not affected
Bycatch species
Seabirds
Reduction technique
Bird-scaring devices
Sub-surface bait setting
Fishing Gear
Hooks-and-Lines

Integrated weight longlines with paired streamer lines - best practice to prevent seabird bycatch in demersal longline

Study Type
Field study in the wild
Location
Bering Sea
Target catch
Pacific cod
Effect on bycatch species
Integrated weight longlines paired with streamer lines eliminated surface foraging and shearwater catch by 97%; integrated weigh longlines reduced surface forager catch rates by 91% and unweighted longlines with paired streamer by 98%
Effect on target catch
Target catch rates were not affected
Bycatch species
Seabirds
Reduction technique
Bird-scaring devices
Sub-surface bait setting
Fishing Gear
Hooks-and-Lines

Integrated weight longlines with paired streamer lines - best practice to prevent seabird bycatch in demersal longline

Study Type
Field study in the wild
Location
Bering Sea
Target catch
Pacific cod
Effect on bycatch species
Integrated weight longlines paired with streamer lines eliminated surface foraging and shearwater catch by 97%; integrated weigh longlines reduced surface forager catch rates by 91% and unweighted longlines with paired streamer by 98%
Effect on target catch
Target catch rates were not affected
Bycatch species
Seabirds
Reduction technique
Bird-scaring devices
Sub-surface bait setting
Fishing Gear
Hooks-and-Lines

Case Studies in North Atlantic Right Whale Fishing Gear Entanglements

Entanglement in commercial fishing ropes threatens the recovery of the North Atlantic right whale (Eubalaena glacialis), a species largely restricted to waters off of eastern North America. In recent years, serious entanglements have been increasing, and mortality from conflicts with fishing operations exceeds US legal mandates, with 83% of the population showing incidence of scarring as a consequence of these encounters.

North Atlantic Right whale entanglement case studies

Authors
Knowlton, A.R., J. Robbins, S. Landry, H.A. McKenna, S.D. Kraus, and T.B. Werner
File

New map tool for seabirds

American Bird Conservancy has launched a website (fisheryandseabird.info) to assist fisheries evaluators and managers to better understand the potential seabirds affected by their fisheries and to reduce bycatch.

Hundreds of thousands of birds are injured or killed every year in fisheries around the world. This new website puts a wealth of information helpful in reducing bycatch right at the fingertips of those who need it most—fishermen, conservationists, and those promoting fishery sustainability. The web-based map tool—Seabird Maps & Information for Fisheries—provides information on seabirds in fisheries and can help to evaluate and reduce seabird bycatch.

New publication on baleen whale bycatch

The Consortium-sponsored research shows that reducing excess rope strength in fishing gear could cut North Atlantic right whale deaths from entanglements by 72 percent.

 

Reducing Excess Rope Strength in Fishing Gear

Could Cut Whale Deaths from Entanglements by 72 percent

BOSTON (December 2015) - Along the U.S. East Coast and the Canadian Maritimes, reports of a whale entangled in ropes used in commercial fishing are a near weekly event. When a whale gets entangled in these ropes, the event can lead to either immediate death by drowning, or delayed death from impaired feeding or infection as a result of deep injuries. It can be a long, painful process of dying for these entangled whales.

Taut vertical line and North Atlantic right whale flipper interaction: Experimental observations

Submitted by morgaac on

Interactions between vertical lines under increased tension with a physical model of a North Atlantic right whale flipper was investigated. This was an updated experiment. The original flipper model was based on data (flipper outlines and bone measurements) collected from three different whales. The physical flipper was computer generated from these data and covered with 1/2 in neoprene rubber, which was overlayed with 1/8 in thick vinyl rubber sheeting. The flipper was made from fiberglass, was free flooding and covered with 1/2 in neoprene and then with 1/8 in vinyl-rubber.

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Taut vertical line and North Atlantic right whale flipper interaction: Experimental observations

Study Type
Field study in the wild
Location
Maine
Target catch
N/A
Effect on bycatch species
Interactions between the vertical line and the leading edge of a whale flipper model closest to the whale "body" resulted in significant damage to the flipper.
Effect on target catch
N/A
Bycatch species
Eubalaena glacialis (NA Right whale)
Reduction technique
High tension rope
Fishing Gear
Traps

Taut vertical line and North Atlantic right whale flipper interaction: Experimental observations

Study Type
Field study in the wild
Location
Maine
Target catch
N/A
Effect on bycatch species
Interactions between the vertical line and the leading edge of a whale flipper model closest to the whale "body" resulted in significant damage to the flipper.
Effect on target catch
N/A
Bycatch species
Eubalaena glacialis (NA Right whale)
Reduction technique
High tension rope
Fishing Gear
Traps

Taut vertical line and North Atlantic right whale flipper interaction: Experimental observations

Study Type
Field study in the wild
Location
Maine
Target catch
N/A
Effect on bycatch species
Interactions between the vertical line and the leading edge of a whale flipper model closest to the whale "body" resulted in significant damage to the flipper.
Effect on target catch
N/A
Bycatch species
Eubalaena glacialis (NA Right whale)
Reduction technique
High tension rope
Fishing Gear
Traps

Assessments of vision to reduce right whale entanglements

Submitted by morgaac on

This study investigated whether North Atlantic right whale behavior changes, in terms of response distance, to changing visual characteristics of rope mimics in their path. 20 ft rope mimics were made from two 10 ft sections of rigid PVC pipe, with an approximate diameter of 1 inch. The rope mimics were weighted and attached to a lobster buoy to simulate a vertical line in the water column. A 30.5 cm disk was placed around the rope for reference use in video footage. The following color ropes were used: black, green, two types of white (white and glow in the dark), orange and red.

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Testing the effectiveness of an acoustic deterrent for gray whales along the Oregon Coast

Submitted by morgaac on

Low-powered sound sources were tested for their ability to deter gray whales from potentially harmful areas. An acoustic device (1-s frequency modulated 1-3 kHz warble deterrent signal) was moored to the seafloor in the gray whales migration path off central Oregon. Observers (land based) tracked whales with a theodolite to locate whales as they passed the headland. Tracklines were compared between times when the acoustic deterrent was on and off.

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