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This study trialed the use of  on-demand, acoustic recovery systems/ on-demand gear (ODGs) as an alternative to vertical buoy lines (VBLs) to reduce North Atlantic right whale (Eubalaena glacialis) entanglement risk in commercial lobster and crap trap fisheries in offshore New England (United States). Trials occurred between 2020 and 2023, and 5,798 hauls were completed using 10 different ODG prototypes. Recovery success of hauls increased throughout the trials as participants gained more experience with the gear, and fishers were able to use the gear to successfully access areas that prohibit VBLs. 

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  to minke whales (Balaenoptera acutorostrata), humpback whales (Megaptera novaeangliae), basking sharks (Cetorhinus maximus), 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.

The authors performed modeling on 10 years of logbook data to analyze environmental and operational factors that influence shark and odontocete depredation in the New Caledonian longline tuna fishery. Results suggest that there are "hotspots" of odontocete depredation, and that it is driven by environmental factors such as sea surface temperature and bathymetry, while shark depredation is driven by operational fisheries factors such as soaking time and number of hooks. Alterations such as reducing soaking time to under 12 hours, or setting limits on hooks to <1,750, could significantly reduce the likelihood of depredation. 

The authors modeled 28 years of data to estimate the impact of entanglement on female North Atlantic right whale (Eubalaena glacialis) health, survival and reproduction. Results show that entangled whales were drastically more likely to experience negative health impacts, including declines in body condition and lower survival rates. Furthermore, whales in poor body condition were not reproductive- between 1994 and 2021, entanglements reduced the expected number of calves by 12.9% and the number of living females by 18.5%. The authors state that reducing entanglement risk is crucial in order for the population to recover. 

The authors conducted field studies off the coast of Iceland to measure the response of humpback whales (Megaptera noveangliae) in their feeding grounds to a whale pinger and seal scarer (acoustic deterrents). Results indicate that whale pingers caused a significant increase in humpback swimming speed and a significant decrease in surface feeding, and that seal scarers caused no significant, consistent behavioral changes.  Additionally, the authors conducted a field trial of whale pingers on a capelin (Mallotus villosus) purse seine; the pingers did usually deter whales from the purse seine, and the two times that whales entered the net, the pingers combined with crew responsiveness seemed to aid their escape. Whale pingers can be a useful humpback whale entanglement mitigation tool, but they should be used only short-term so as to avoid reduced fitness consequences.

The authors conducted field studies off the coast of Iceland to measure the response of humpback whales (Megaptera noveangliae) in their feeding grounds to a whale pinger and seal scarer (acoustic deterrents). Results indicate that whale pingers caused a significant increase in humpback swimming speed and a significant decrease in surface feeding, and that seal scarers caused no significant, consistent behavioral changes.  Additionally, the authors conducted a field trial of whale pingers on a capelin (Mallotus villosus) purse seine; the pingers did usually deter whales from the purse seine, and the two times that whales entered the net, the pingers combined with crew responsiveness seemed to aid their escape. Whale pingers can be a useful humpback whale entanglement mitigation tool, but they should be used only short-term so as to avoid reduced fitness consequences.

The PearlNet aims to mitigate odontocete bycatch in bottom-set gillnets by enhancing the acoustic visibility of nets through the incorporation of small, acrylic glass spheres. This study found that PearlNet performed similarly to standard nets in terms of catch efficiency and handling time of gear. Performance of the gear in reducing marine mammal bycatch was not assessed during this study, however, no mammal bycatch was reported. 

Potential risk of fisheries to cetaceans was assessed using a screening procedure based on a Productivity Susceptibility Analysis (PSA) using gears found in Ireland. Gillnets targeting demersal species was assessed as the fishery posing the greatest risk to cetaceans. Pelagic trawls targeting small pelagic species was found to pose a moderate risk to cetaceans. Specific gear-species interactions were also identified, such as humpback whales (Megaptera novaeangliae) and pots/traps.  

Direct interactions between longline fisheries and many top predators such as toothed whales result in substatial impacts on fishing activity; depredating species and fish stocks. These issues continue to be a growing concern in fisheries worldwide, including the French Patagonian toothfish (Dissostichus eleginoides) fishery. In this field study, researchers deployed data loggers on killer whales (Orcinus orca) and sperm whales (Physeter macrocephalus) while aboard commercial toothfish demersal longline fishing vessels to gain insight into when, where and how depredation occurs. Data from odontocete tracking loggers and longline accelerometer loggers reveal both species are able to depredate longlines on the seafloor. Findings from this study suggest depredation can occur at anytime during the whole fishing process.      

This investigation details an unusual encounter with a lunge-feeding minke whale (Balaenoptera acutorostrata) with fresh entanglement-like injuries to its head and ventral pouch.  It also discusses results from a short-term comparative study that tested whether the whale fed differently than five uninjured minke whales feeding in the same area.  Collectively, this study: 1) quantifies how much a rope-like injury can restrict the expansion of a minke's ventral pouch while feeding, 2) provides the first minke whale lunge-feeding velocities from a photogrammetric method using digital video, and 3) describes a new lunge-feeding aerial maneuver for minke whales that is possibly associated with the injury.