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Monkfish in the US mid-Atlantic and northeast are targeted through sink gillnets that also capture Atlantic sturgeon. Large-mesh gillnets are required to fish seasonally using tie-downs as part of the Harbor Porpoise Take Reduction Plan. This study looked at the effects of tie-downs (control: 12 meshes x 30.5 cm stretch mesh with four mesh tie-downs, experimental: same, no tie-downs) on Atlantic stureon and marine mammal bycatch. Atlantic sturgeon bycatch (CPUE) did not differ between gillnet configurations.The experimental gillnets without tie-downs significantly decreased monkfish landings and resulted in common dolphin mortalities.       

Four types of tori-lines (long streamer, light streamer, hybrid streamer and modified light streamer) were tested for their ability to reduce seabird bycatch on commercial longline fishing vessels in the north Pacific Ocean.  Two experiments were undertaken 1) determine the frequency of bycatch of Laysan albatross for each tori-line and 2) determine mean rate of attacks for tori-lines.  In experiement 1, the mean number of seabirds appearing and the catch per unit effort (for seabirds) was not statistically different between the four tori-lines.  In experiment 2, seabird attack rates (Laysan albatross and shearwater) were not statistically different nor were bycatch rates of Laysan albatross among the four tori-line types.

Two types of tori-lines (tori-line and tori-line light streamer) were tested aboard commercial and research longline vessels in the western North Pacific to determine their effectiveness for seabird avoidance.  The tori-line light streamer reduced bait-taking behavior (primarily Laysan albatross) and bycatch of seabirds (primarily Laysan albatross) compared to the tori-line.  Therefore, the tori-line light streamer is a good option for avoiding seabird bycatch in this longline fishery.

In northern hemisphere trawl fisheries, little is known about the extent of cable strike seabird mortality or techniques to mitigate it. We compared the rate of heavy seabird strikes by third-wire cables and warps, using three mitigation measures compared to a control of no mitigation. Experiments were conducted aboard two catcher-processor vessels targeting walleye pollock (Theragra chalcogramma) in the eastern Bering Sea: one that rendered offal into fish meal and fish oil (Vessel R) and one that minced offal prior to discharge (Vessel M). More birds attended Vessel M, but the rate of seabird cable strikes was higher on Vessel R due to the greater aerial extent of its cables. Streamer lines significantly reduced heavy seabird strikes by both cable types regardless of discharge characteristics. Reducing the aerial extent of third wires also reduced third-wire strike rates, but this method was less effective than streamer lines. Warp booms designed to divert seabirds from warps failed to reduce seabird warp strikes, but this technique could be improved. These results show for the first time that seabird strikes with modern third-wire trawl sonar cable systems can be reduced through mitigation or gear modification and that warp strikes can be mitigated with techniques similar to those found successful in southern hemisphere fisheries. 

In northern hemisphere trawl fisheries, little is known about the extent of cable strike seabird mortality or techniques to mitigate it. We compared the rate of heavy seabird strikes by third-wire cables and warps, using three mitigation measures compared to a control of no mitigation. Experiments were conducted aboard two catcher-processor vessels targeting walleye pollock (Theragra chalcogramma) in the eastern Bering Sea: one that rendered offal into fish meal and fish oil (Vessel R) and one that minced offal prior to discharge (Vessel M). More birds attended Vessel M, but the rate of seabird cable strikes was higher on Vessel R due to the greater aerial extent of its cables. Streamer lines significantly reduced heavy seabird strikes by both cable types regardless of discharge characteristics. Reducing the aerial extent of third wires also reduced third-wire strike rates, but this method was less effective than streamer lines. Warp booms designed to divert seabirds from warps failed to reduce seabird warp strikes, but this technique could be improved. These results show for the first time that seabird strikes with modern third-wire trawl sonar cable systems can be reduced through mitigation or gear modification and that warp strikes can be mitigated with techniques similar to those found successful in southern hemisphere fisheries. 

Visual cues are important in sea turtle foraging behavior and likely influence their interaction with fishing gear. This studey examined the potential effectiveness of three visual cues: 1) shark shapes, 2) illumination of nets by LED lights, and 3) nets illuminated with chemical lightsticks - for reducing green sea turtle bycatch in gillnets. The presence of shark shapes significantly reduced mean sea turtle catch rates by 54%, but also reduced target catch by 45%. Nets illuminated with LED lights significantly reduced sea turlte bycatch by 40% and had negligable impact on target catch. Lastly, nets illuminated with chemical lightsticks also reduced sea turtle catch rates by 60% and had no significant impact on target catch. 

Visual cues are important in sea turtle foraging behavior and likely influence their interaction with fishing gear. This studey examined the potential effectiveness of three visual cues: 1) shark shapes, 2) illumination of nets by LED lights, and 3) nets illuminated with chemical lightsticks - for reducing green sea turtle bycatch in gillnets. The presence of shark shapes significantly reduced mean sea turtle catch rates by 54%, but also reduced target catch by 45%. Nets illuminated with LED lights significantly reduced sea turlte bycatch by 40% and had negligable impact on target catch. Lastly, nets illuminated with chemical lightsticks also reduced sea turtle catch rates by 60% and had no significant impact on target catch. 

Visual cues are important in sea turtle foraging behavior and likely influence their interaction with fishing gear. This studey examined the potential effectiveness of three visual cues: 1) shark shapes, 2) illumination of nets by LED lights, and 3) nets illuminated with chemical lightsticks - for reducing green sea turtle bycatch in gillnets. The presence of shark shapes significantly reduced mean sea turtle catch rates by 54%, but also reduced target catch by 45%. Nets illuminated with LED lights significantly reduced sea turlte bycatch by 40% and had negligable impact on target catch. Lastly, nets illuminated with chemical lightsticks also reduced sea turtle catch rates by 60% and had no significant impact on target catch. 

Experiments were conducted in California to determine the effect of hook type (circle and J-type) on anatomical hook location and subsequent growth and mortality rates of white seabass.  Juvenile white seabass were captured with 4/0 offset circle hooks, J-type hooks or a control net.  There was a significant difference in hook location between the two types of hooks, with more fish being hooked in the lip with the circle hooks.  The majority of mortality occured in fish with hook damage to the esophagus but equal numbers of these fish were caught on the two hook types.  Deeply hooked fish died 65% of the time when hooks were removed and 41% of the time when they were left embedded regardless of hook type.  White seabass caught on circle hooks grew at a significantly faster rate compared to those caught on J-type hooks or in the control net.  The results suggest catch-and-release mortality should be included in management plans for this species.

Tests were conducted in the Gulf of Maine to determine the effectivenss of a new Rope Grid in reducing the bycatch of small finfish in the pink shrimp (Pandalus borealis) trawl fishery.  The new Rope Grid was constructed by removing two-thrids of the netting surrounding the traditional Nordmore Grid and replacing it with four ropes.  This new Rope Grid was tested against the traditional Nordmore Grid during sea trials.  The new Rope Grid significantly reduced the bycatch of silver hake, red hake, American plaice and witch flounder compared to the Nordmore Grid but did not significantly reduce catches or the size of targeted pink shrimp.  The new Rope Grid allowed larger fish to escape compared to the Nordmore Grid.