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This paper reports on successful seabird mitigation methods implemented in a CCAMLR fishery. The sub-Antarctic Patagonian toothfish fisheryhad a high seabird bycatch mortality rate, particularly of black-browed albatross and white-chinned petrels, when it began (>5,000 birds per 1,000 hooks); due to successful mitigation measures and compliance, it has since significantly reduced (<0.01 bird per 1,000 hooks). A multitude of measures were implemented, and the following measures are considered to have been important in reducing mortality: restricting the fishery to only operating in the austral winter, using novel marked hooks, 100% observer coverage, restricting longline setting to only occur during nighttime, and requiring weighted hooks so that lines sink rapidly. 

Using modeling (specifically Bayesian multilevel network meta-regression modelling), this  study presents a synthesis of the effectiveness of alternative pelagic longline weighting in mitigating seabird bycatch.  There is a high probability (97%) that all weighting designs do reduce seabird bycatch when compared to no weight, but the designs with weights >60g and >1m from the hook performed significantly better than designs with less weight but attached closer to the hook. 

This study investigated and summarized trends in US marine mammal bycatch from 1990-2017. Total annual bycatch was estimated to be 4296 ± 1789 individuals, and the vast majority occurred in gillnets; 52% of marine mammal bycatch consisted of pinnipeds, while the other 48% was cetaceans. Total marine mammal bycatch in US fisheries declined from 1990 to 2002 following the passage of the MMPA in 1972, but there was no change in total bycatch from 2002 to 2017, suggesting that US bycatch mitigation measures have had some success. While bycatch levels declined through 2017 in the Atlantic-Gulf of Mexico-Carribbean region, reductions either halted or increased in the Pacific in Atlantic regions by 2006. 

This paper assessed richness, distribution, and incidental catch of benthic sessile invertebrates in the Great Amazon Reef System (GARS)  based on records and photographs collected from onboard observers between 2015 and 2022. In total, 54 distinct species were recorded as bycatch, with most being echinoderms. Gillnet and trawl fisheries pose great threats to the GARS, and over time this bycatch may profoundly disturb benthic reef communities and therefore reduce fishery yields.

This study measured deep-sea elasmobranch (DSE) bycatch on a commercial crustacean bottom trawler off of southern Portugal between June 2020 and May 2022, and collected data from Global Fishing Watch to estimate the bycatch of deep-sea sharks since 2017, which is the year that trawling below 800m was banned in the region. DSE represents a high proportion of total catch biomass, especially at depths below 800m; despite EU regulations restricting fishing to only occur above 800m, bottom trawlers were regularly observed operating below that depth. Analyses suggest that substantial numbers of DSE have been caught in the five years following the prohibition on bottom trawling below 800m in the Northeast Atlantic. 

The authors trialed the effectiveness of green LED lights to reduce sea turtle bycatch in bottom-set gill and trammel nets in the northeastern Adriatic Sea (territorial waters of Croatia and Slovenia) . The result was no significant change in sea turtle bycatch, and a significant decrease (35%) of primary target catch. Although net illumination has been highly effective (up to 93%) in reducing sea turtle bycatch in other regions, this study highlights the importance of regional variability in mitigation measures.

Through on-board fishing vessel observations and Autonomous Underwater Vehicle (AUV) transects, this study explored the impact of trammel nets on cold-water gorgonian (soft coral) populations in the Northwestern Mediterranean Sea. High bycatch of gorgonians, especially larger colonies with greater than average height, was observed in the majority of assessed nets at an average rate of 2.4 ± 0.8 colonies or fragments per 200m of net. Impact was higher in specific areas below 80m depth and where wave heights were greater than 1m. Trammel nets mostly caught large colonies with greater height than average. Impact could be significantly mitigated by measures such as avoiding fishing at 80-90m depth during adverse weather conditions.

The authors worked with creel fishers to trial and assess whether sinking rope was practical to fish with in Scottish inshore waters, and therefore to reduce entanglement risk of minke whales, humpback whales, and other megafauna. Overall, the fishers reported few problems with the modified gear, and the gear performed well underwater according to Remotely Operated Vehicle (ROV) footage and sensors. Sinking rope may be a simple, viable option to reduce entanglement risk in the Scottish creel fishery.