The Patagonian toothfish longline fishery has high levels of depredation by killer and sperm whales, which puts the whales at risk of being bycatch. Observations from 2003 to 2008 revealed significant variations of interaction rates with killer whales between vessels, suggesting the influence of operational factors on vessel interaction and depredation. When killer whales were […]
Development and observations of spiny dogfish Squalus acanthias reduction device in a raised footrope silver hake Merluccius bilinearis trawl | Consortium for Wildlife Bycatch Reduction
An excluder grate (grid) was tested in the silver hake trawl fishery in Massachusetts Bay to determine it’s effectiveness in reducing spiny dogfish bycatch. The effects of color (white or black), angle and direction of the 50 mm spaced grids were investigated through video observations and data collection. The number of spiny dogfish caught in […]
Rope-less fishing technology development | Consortium for Wildlife Bycatch Reduction
This article describes the design and fabrication of a prototype rope-less fishing system that might be used in the Gulf of Maine lobster fishery. Rope-less fishing gear, which secures vertical fishing lines to the bottom until they are released for hauling, is a potential mitigation measure to reduce vertical line entanglements of marine mammals including […]
North Atlantic right whales (Eubalaena glacialis) ignore ships but respond to alerting stimuli | Consortium for Wildlife Bycatch Reduction
Risk factors involving ship strikes and North Atlantic right whales were investigated in this study. A multi-sensor digital acoustic recording tag (DTAG) was used to measure the responses of whales to four stimuli: vessel noise, social sounds of conspecifics, and a signal designed to alert whales. Silence was used as the control measure. Testing was […]
Gear technology in Nephrops trawl fisheries | Consortium for Wildlife Bycatch Reduction
This paper presents a review of studies on gear technologies used to improve species and size selection in Nephrops trawl fisheries in the North Sea, Irish Sea, Kattegat and Skaggerak. The following categories of gear modifications were analyzed: separator grids, separator/guiding panels, square-mesh panels, capture avoidance designs, and codend modifications. The best gear design depends […]
Review of sinking groundline performance in the Maine lobster fishery, with recommendations for improving its fishability | Consortium for Wildlife Bycatch Reduction
The purpose of this project was to determine ways to enhance the performance of sinking groundline, involving three approaches: (1) Reviewing previous research and lobstermen’s experience with sinking groundlines; (2) Recording directly from lobster fishermen of the Gulf of Maine the practical challenges they encountered in converting to sinking groundline; (3) Producing visual observations of actively […]
Experiment to Evaluate Gear Modification on Rates of Sea Turtle Bycatch in the Swordfish Longline Fishery in the Azores Phase 4 | Consortium for Wildlife Bycatch Reduction
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 […]
Developing ultraviolet illumination of gillnets as a method to reduce sea turtle bycatch | Consortium for Wildlife Bycatch Reduction
Two experiments were conducted to determine if 1) UV illumination reduced green sea turtle capture rates in large mesh gilllnets and 2) what was the impact of UV illumination on target catch rates in bottom-set gillnets. Paired tests were conducted using a control net and an experimental net with UV LEDs placed every 5 m […]
Chilean Dolphin | Consortium for Wildlife Bycatch Reduction
Historically, the Chilean dolphin has been hunted both for food and for crab bait (Reeves et al 2008). Although cetaceans are now protected by law in Chile (Torres et al 1979), regulation enforcement is virtually nonexistent and temptation is high for impoverished fishermen to supplement their income by killing dolphins for bait (Dawson 2009; Reeves […]
Design, testing, and evaluation of an acoustic release system for offshore lobster pot buoy lines | Consortium for Wildlife Bycatch Reduction
An acoustic release system for offshore lobster buoy lines was successfully developed and tested for reducing right whale (Eubalanea glacialis) entanglements with vertical lines in the Gulf of Maine and southern New England lobster pot fishery.
Target strength of a nylon monofilament and an acoustically enhanced gillnet: predictions of biosonar detection ranges | Consortium for Wildlife Bycatch Reduction
Metal oxide nets made from barium sulphate increased the detectability of gillnets by marine mammals when compared to nylon nets when approached at angles of incidence greater than normal incidence but less than 40 degrees. Hypothesized detection ranges indicate bottlenose dolphins (Tursiops truncatus) should be able to detect metal oxide nets in time to avoid […]
White-chinned petrel | Consortium for Wildlife Bycatch Reduction
The white-chinned petrel is the most common avian bycatch species in the Southern Ocean (Weimerskirch et al 1999; Gilman 2006; Robertson et al 2006; Birdlife International 2013). The high bycatch rate is due to seabirds, such as petrels, being attracted to pelagic and demersal longlines by bait and offal discarded from vessels (Gilman 2006; Bugoni […]
The response of sea turtles to vocalizations opens new perspectives to reduce their bycatch | Consortium for Wildlife Bycatch Reduction
This study recorded and analyzed vocalizations of green sea turtles off the Carribbean island of Martinique, and identified which sounds seemed to be linked to flight, fear, and social aspects. When these recordings of sea turtles were played to wild sea turtles, they demonstrated behavioral responses (vigilance and/or escape) to the sounds they produce, suggesting […]
Harbor Porpoise | Consortium for Wildlife Bycatch Reduction
Although it is believed that the harbor porpoise population is not seriously in danger at present, incidental catch of the species in gillnets continues to be the primary threat throughout its range (Hammond et al 2008). Off the eastern coast of the US, an estimated 1200 to 2900 harbor porpoises were killed annually in gillnets […]