Environmental Science · Global and Planetary Change
People have fished for tuna for about 44,000 years and billfish for about 10,000 years, according to a global review of archaeological evidence. But sustained, intensive fishing in offshore and oceanic waters appears to have developed mainly during the past 200 years.
Humpback whales in Monterey Bay fed more frequently when California sea lions were present. The whales appeared to spend less time searching and approaching prey, while the effort and movement of individual lunges showed no detectable increase.
Humpback and fin whales often move into killer whales’ herring-hunting groups in northern Norway, feeding on dense patches that the killer whales have gathered. The intrusions can end killer whale hunts, while whale-watching tourism adds further disruption to feeding.
Large groups of mahi-mahi may interfere with striped marlin hunting at shared prey schools, causing the marlin to abandon a hunt. The study also found that smaller numbers of mahi-mahi may increase the marlin’s net captures.
Satellite tracking of 21 southern right whales from Aotearoa New Zealand found that they used one of two routes to reach shared summer feeding grounds. The results suggest the whales may balance faster travel against lower energy costs, while adjusting their route as individuals.
A review of 51 Pacific salmon reintroduction programs in western North America found that most assessed populations were stable or increasing. The authors also describe ecological and cultural benefits, while emphasizing the need to identify and reduce risks linked to reintroduction and to inaction.
A data-driven analysis of the central and western Baltic Sea identified ecosystem risk hotspots where low oxygen near the seafloor, depth-related constraints and fishing pressure occurred together. These areas also had relatively high species abundance, according to analyses of 2020 data covering 145 marine species.
A study of temperate kelp forests along 600 kilometers of Baja California found that reef states after the 2014–2016 marine heatwave supported very different contributions to ecosystems and people. Reefs with persistent canopy-forming kelp generally supported more fish biomass, ecological functions and nutritional supply than simplified reefs.
A study mapped where gillnet fisheries and 13 cetacean species occur in Brazil’s Santos Basin. Guiana dolphins, franciscanas and bottlenose dolphins showed the greatest spatial overlap with the fisheries, highlighting areas for bycatch monitoring and management.
A study of catch-and-release bogue found that deeply hooked fish had similar survival outcomes whether anglers used a de-hooker or cut the line. Loss of orientation and bleeding were associated with mortality, making prevention of deep hooking the most effective way to reduce harm.
Illegal fishing can enter seafood markets through ship-to-ship transfers, weakly regulated ports and false documents. The article estimates that illicit marine wild-fish seafood trade totals 8.4 to 15.4 million metric tons a year and is worth $6.2 billion to $12.2 billion, while noting that proposed solutions still need more research.
