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Paired trials were conducted to compare standard gillnet, trammel nets, and set longlines in Türkiye with several different types of modifications: LED (LP Electralume, 520–530 nm; 18,000–20,000 mcd) and UV-LED devices (LP Electralume, 395–400 nm; 12,000 mcd) and C-type fishing hooks. 

Compared to control nets, LED and UV-illuminated gillnets and trammel nets reduced the biomass of commercial species catch  by 54-75%, and there was no significant reduction in the catch of vulnerable species, including elasmobranchs and sea turtles.  Circle hooks reduced commercial catch by 77% compared to standard J-hooks and similarly had a higher proportion of vulnerable species (noting no sea turtles were captured in the control or treatment longline sets). 

These somewhat unexpected findings may have been influenced by study design limitations (small sample size) or other variables, including high turbidity and larger gear mesh sizes. Additional research is planned. 

Four experimental snow crab (Chionoecetes opilio) conical pots with non-selective, small mesh jackets  and collars of 180 mm, 240 mm, 300 mm, and 180 mm with a 51 mm lip, were compared with small mesh pots with no collar and traditional pots with traditional mesh in Conception Bay, Canada. Smaller collars did not improve catch efficiency (but did not significantly reduce target catch), and caught large amounts of sub-legal and female crabs.  Additionally, larger collars substantially reduced catch of target-sized crabs (although sub-legal catch was also reduced). Future work will integrate escape gaps to assist escapement. 

This study examined the effectiveness of three electronic bycatch reduction devices with different signal frequencies and duty cycles (100% duty cycle fixed signal, 50% duty cycle fixed signal, 100% duty cycle quasi-random signal) in a laboratory experiment on Atlantic dogfish (Squalus acanthias). The results suggest that time-varying electrical signals can deter spiny dogfish from baited hooks. The researchers observed a reduction in bait consumption, mean bite rate, and probability of bait consumption from all three prototypes . The lowest bait consumption occurred with the 100% duty cycle, fixed-signal BRD, while the largest treatment differences resulted from the BRD with 100% duty cycle emitting a quasi-random frequency. 

The study evaluated if green LED lights and pulsed electrical deterrents (SharkGuard) could reduce bycatch of threatened elasmobranchs in Northern Australia gillnet fisheries. 23 paired deployments of LED lights (Fishtek Marine) and 7 electric deterrent trials were analyzed. Nets with green LED lights caught 35% fewer elasmobranchs, while also resulting in a significant increase (76%) of bony fish catch (however, commercially-targeted species of bony fish were not caught significantly more in the LED nets). Electric deterrents did not significantly reduce bycatch or fish catch, however, the small sample size limits the ability to detect meaningful effects. Both green LEDs and electric deterrents showed moderate effects related to reduced sawfish (Pristis clavata, P. zijsron, Anoxypristis cuspidata) catch per unit effort (CPUE), particularly for the electrical deterrents, which could be explored in a larger study. 

Studies in the Mediterranean and Atlantic swordfish (Xiphias gladius) fisheries have reported that looplines/traplines or Meka-rings are increasingly being used. Loop lines consist of concentric monofilament loops attached to the branch line, replacing conventional hook and bait. Available evidence suggests that this device may enhance swordfish catch rates while exhibiting high selectivity and reduced bycatch of non-target species (less bait in the water attracts fewer predators and scavengers). However, looplines may also have drawbacks, including more stress on the captured organism and increased drag during retrieval. In addition, loop lines are not yet formally recognized as a separate gear type, which may impact fisheries management. 

This study evaluated the effectiveness of updated best handling and release practices, as well as a custom-designed shark release ramp, in improving the post-release survival of sharks onboard a U.S. purse seine vessel. 98.5% of sharks were released using the ramp system, with release times averaging under two minutes. 47% of captured sharks exhibited poor or moribund condition at haul-back. Tagging data from three released sharks indicated survival or likely survival post-release. While the ramp system with a hopper improved operational efficiency and enhanced crew safety, wider tagging efforts is needed to validate improved survivability of sharks post-release. 

This paper is a global review of seabird bycatch in gillnets. The authors identified 148 seabird species as susceptible to bycatch in gillnets, of which 81 have been recorded incidentally caught. A review of reported bycatch estimates suggests that at least 400,000 birds die in gillnets each year. The highest levels of bycatch are reported in the Northwest Pacific, Iceland, and the Baltic Sea.  

The addition of a prototype "tunnel excluder" consisting of a filter grid (inclined at ca. 20 degrees) that leads to an escape tunnel in the Mauritanian industrial trawl fishery nets achieved a 40-100% reduction in bycatch of vulnerable species, including allowing 100% of rays and turtles to escape, 75% of manta rays, 40% of billfish and between 20-75% of sharks to escape. Cetaceans were less likely to use the tunnel to escape due to the narrowness of the design. 

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 (in primarily Laysan albatross, Phoebastria immutabilis) 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.

Fishery observer data from Japanese longline vessels targeting southern bluefin tuna (Thunnus maccoyii) was used to determine if there were differences in seabird avoidance between two types ("WCPFC type" and "Light type") of tori-lines.  There was no significant difference between the two tori-lines for either the nominal catch rates of albatross or the per-capita catch rates.  Therefore both types of tori-line have similar seabird avoidance effects and the "Light type" may be more practical in areas with difficult weather and oceanic conditions.