Researchers deployed LED lights on the floatlines of paired gillnets (control vs illuminated net) during 864 fishing sets by small-scale vessels departing from three Peruvian ports between 2015 and 2018. Bycatch probability per set for sea turtles, cetaceans and seabirds as well as catch per unit effort (CPUE) of target species were analyzed for illuminated and control nets using a generalized linear mixed-effects model (GLMM). For illuminated nets, bycatch probability per set was reduced by up to 74.4 % for sea turtles and 70.8 % for small cetaceans in comparison to non-illuminated, control nets. For seabirds, nominal BPUEs decreased by 84.0 % in the presence of LEDs. Target species CPUE was not negatively affected by the presence of LEDs. This study highlights the efficacy of net illumination as a multi-taxa BRT for small-scale gillnet fisheries in Peru. 

The focus of this study was to compare two selective devices in a trawl by automated counting of fish escapements through each selective device (a white and black square mesh panel) based on video sequencing and an algorithm for automated object detection and tracking. The software detected a significant difference in fish escapement rate according to net color- 60% of all fish escaped through the white panel, suggesting that net color influences the escape rate of fish. The color of the selective device should therefore be investigated further with the aim of increasing selection efficiency. Further development of the software could be done to identify species and size of the fish and assess the effectiveness of a selective device by species and size.

The study quantified the impact of turtle excluder devices (TEDs) on the catches of various elasmobranchs caught off northern Australia using data collected during a previous study (Brewer, et al., 2006). The effect of fish size and various aspects of TED design such as grid orientation, grid angle, and bar space were quantified to determine their effect on the escape of elasmobranchs from shrimp trawls. The relatively low number of elasmobranchs encountered during sampling resulted in a lack of power to isolate the effects of the various factors tested. Generally, the study showed that TEDs facilitated the escape of large elasmobranchs, including several species of conservation interest (the scalloped hammerhead, Sphyrna lewini and the zebra shark, Stegostoma fasciatum). Bar space and orientation were important TED design factors affecting the escape of elasmobranchs. Top-shooter TEDs enabled more Carcharhiniformes (“ground sharks”, including requiem sharks and hammerhead sharks) to escape penaeid trawls, while bottom-shooter TEDs increased the escape of Myliobatiformes (rays, including stingrays and cownose rays). However, the TED bar space that facilitates maximum escape of elasmobranchs while maintaining catch of the target species is more difficult to quantify given the low catch rate of elasmobranchs in the trawls. 

The Pacific hake (Merluccius productus) midwater trawl fishery is the largest groundfish fishery off the U.S. West Coast by volume. However, bycatch of Chinook salmon can be an issue as Endangered Species Act (ESA)-listed Evolutionarily Significant Units represent a portion of the total Chinook salmon bycatch. This study investigated the influence of artificial illumination on Chinook salmon behavior and their escapement out of a bycatch reduction device (BRD) in a Pacific hake midwater trawl. Artificial illumination can influence where Chinook salmon exit out of the BRD and can also enhance their escapement overall. As conservation of ESA listed Chinook salmon is an ongoing management priority, this research contributes new information on how artificial illumination can minimize adverse interactions between the Pacific hake fishery and Chinook salmon.