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Field experiments were conducted to determine behavioral responses of minke whales to experimental ropes and buoys made up of different colors, simulating those used in crab and whelk fishing gear. Trials were conducted with yellow, orange, green, blue, white and black ropes. Visual and acoustic monitoring was used to assess behavioral responses of whales to the different experimental gears. In addition, remote sensing equipment was used to monitor oceanographic conditions, underwater sounds and to video the whales as they swam near the experimental ropes. The results indicated a positive correlation between whale approach velocity and depature velocity and bearing changes. Minke whales decreased their swimming velocity and altered their bearing when passing by these ropes and increased their velocity once they had passed by the ropes. This was most evident when the ropes were black and white. Low frequency vocalizations and altered swimming trajectories were also noted in some whales as they passed near the ropes. 

Five biodegrabable twine types were investigated for potential use in the snow crab (Chinoecetes opilio) fishery that operates off Newfoundland and Labrador, Canada. The five twine types included 1) 2-ply Sisal, 2) 3-ply Cotton 60-threated, 3) 3-ply Cotton 72-thread, 4) 3-ply Cotton 96-thread and 5) 3-ply Hemp 40 strand. Each twine was deployed at sea for 124 days and their degradation rates over time were studied. The results indicate variability in twine degradation rates. The 3-ply cotton 96-thread twine was the best performing twine.  Over the study period, this twine rapidly declined in breaking strength. The total reduction was 63% of the initial strength.  In addition, there was a statistical relationship between breaking strength and soak time for three twin types 1) 2-ply Sisal, 2) 3-ply Cotton 60-thread and 3) 3-ply Hemp 40 strand. The 2-ply cotton 96-thread is now required for use by all fisheries in the province of Newfoundland and Labrador targeting snow crabs.

Entanglements of large cetaceans in fishing gear that occurred off the coast of Peru between 1992 and 2012 were catalogued. Direct observations, local news and online graphical evidence was used to identify any entanglements. A total of 15 confirmed entanglements were identified. The species involved in these entanglements included humpback whales (Megaptera novaeangliae), sperm whales (Physeter macrocephalus) and Antarctic minke whale (Balaneoptera bonaerensis). The most common entanglements occurred in gillnets, followed by longlines. This study did not investigate the use of bycatch mitigation techniques.

Entanglements of large cetaceans in fishing gear that occurred off the coast of Peru between 1992 and 2012 were catalogued. Direct observations, local news and online graphical evidence was used to identify any entanglements. A total of 15 confirmed entanglements were identified. The species involved in these entanglements included humpback whales (Megaptera novaeangliae), sperm whales (Physeter macrocephalus) and Antarctic minke whale (Balaneoptera bonaerensis). The most common entanglements occurred in gillnets, followed by longlines. This study did not investigate the use of bycatch mitigation techniques.

This is a comprehensive, critical overview of studies on the use of electrotrawling in the North Sea. Electrotrawling, involves replacing the tickler chains or bobbins with electrical stimulation. The result is reduced contact with bottom habitats, reduced fuel costs and reduced discards. An overview on the current status and implementation of this technique in flatfish, shrimp and razor clam fisheries is provided. In terms of the flatfish fisheries, while electrotrawling is a promising alternative, potential negative impacts (i.e. safe range of pulse parameters, differences in sensitivities of species, effects on early life stages, long-term effects, impact on electrosensitive fish and potential electrolysis effects) were not quantified. Regardless, it appears that electrified trawls are superior to conventional trawls in terms of ecological impacts, management and carbon footprint.

This is a comprehensive, critical overview of studies on the use of electrotrawling in the North Sea. Electrotrawling, involves replacing the tickler chains or bobbins with electrical stimulation. The result is reduced contact with bottom habitats, reduced fuel costs and reduced discards. An overview on the current status and implementation of this technique in flatfish, shrimp and razor clam fisheries is provided. In terms of the flatfish fisheries, while electrotrawling is a promising alternative, potential negative impacts (i.e. safe range of pulse parameters, differences in sensitivities of species, effects on early life stages, long-term effects, impact on electrosensitive fish and potential electrolysis effects) were not quantified. Regardless, it appears that electrified trawls are superior to conventional trawls in terms of ecological impacts, management and carbon footprint.

Field studies were conducted in the tropical northeast Atlantic to determine the effect of different hook types (J and circle) on target, bycatch and discard species caught in pelagic longline fisheries. Tests were conducted comparing J-hooks with squid bait and two circle hooks (non offset and 10 degree offset) with mackerel bait. Swordfish catches were negatively impacted when circle hooks were used. However, bait type had a bigger impact than hook style. Yellowfin tuna and escolar catches were lower when mackerel instead of squid bait was used. Longfin mako shark catch rates were lower when circle hooks were used. Hook style and bait type did not influence at-haulback mortality rates of the majority of discarded species. Based on these results the authors suggest that using circle hooks in this region to reduce sea turtle bycatch would not negatively impact the economic viability of the fishery.

Experimental studies were conducted over a three year period (August 2008-December 2011) to determine the effects of changing traditional J-hooks baited with squid bait to circle hooks (offset and non offset) with mackerel bait on sea turtle interactions. Studies were carried out aboard pelagic longline vessels targeting swordfish in the tropical northeast Atlantic Ocean. Overall, sea turtle interactions were reduced when circle, compared to J-hooks were used. However species specific differences did occur. Leatherback interactions were only reduced when circle hooks with an offset were used. Leatherback interactions can be reduced by 55% in this fishery by switching from J-style to circle hooks. Hardshell turtle interactions were reduced when both circle hook styles and mackerel bait were used. Interactions with hard shelled turtles can be reduced by 50-55% in this fishery by switching from J-style to circle hooks.  A 55% reduction in hardshell turtle bycatch is expected to occurr in this fishery by switching from squid to mackerel bait.

Experimental studies were conducted over a three year period (August 2008-December 2011) to determine the effects of changing traditional J-hooks baited with squid bait to circle hooks (offset and non offset) with mackerel bait on sea turtle interactions. Studies were carried out aboard pelagic longline vessels targeting swordfish in the tropical northeast Atlantic Ocean. Overall, sea turtle interactions were reduced when circle, compared to J-hooks were used. However species specific differences did occur. Leatherback interactions were only reduced when circle hooks with an offset were used. Leatherback interactions can be reduced by 55% in this fishery by switching from J-style to circle hooks. Hardshell turtle interactions were reduced when both circle hook styles and mackerel bait were used. Interactions with hard shelled turtles can be reduced by 50-55% in this fishery by switching from J-style to circle hooks.  A 55% reduction in hardshell turtle bycatch is expected to occurr in this fishery by switching from squid to mackerel bait.

A population viability analysis and evaluations of bycatch mitigation techniques were used to investigate the impact of bycatch mortality on the populations of four freshwater turtles (common snapper, Chelydra serpentina, eastern musk, Sternotherus odoratus, northern map, Graptemys geographica, and painted, Chrysemys picta) incidentally captured in small-scale commercial fisheries operating in Lake Opinicon, Ontario, Canada.  Two approaches to bycatch reduction were investigated. The first was the use of a bycatch reduction device (BRD) and the second was the use of effort reductions (BRSs). The BRD was an exclusion device, which was vertically oriented within the funnel of the nets, which acted as a phycial barrier preventing turtles from entering. The BRSs consisted of reducing the season length.  The population viability analysis results indicated that even low levels of additional bycatch mortality of females (annual) would either result in a reduction of the population sizes or extirpation of the local population within 500 years.  The results also indicated that the use of BRD's and/or BRSs could help reduce the risk of extirpation.  The BRD's reduced the bycatch of snapping turtles by 95-100% and 0-97% for the other three species.  BRSs can also be used to reduce turtle interactions for some species. Specifically, significantly more painted turtles were caught before May 20th, than between May 20th and June 20th. Significantly less snapping turtles were caught before May 20th. No significant differences were found for the other two species. The combined use of the BRD and BRSs would prove beneficial in this fishery.