The Southern Ocean has immense global value, for its ability to regulate global ocean temperature, moderate sea levels, and store carbon, as well as the fundamental role its marine native species play in the food web, feeding marine mammals, seabirds, and fish. However, in a new paper, a group of scientists including UBC researchers say the members of the Commission for the Conservation of Antarctic Marine Living Resources (CCLAMR) and other nations of the world are not protecting it well enough.
“With no Indigenous Peoples in Antarctica, and no local fishing communities, exploitation of the waters surrounding Antarctica has always been the result of industrial distant water activities,” said lead author Dr. Cassandra Brooks, professor of environmental studies at the University of Colorado Boulder. “Species such as toothfish, the region’s top fish predator, Antarctic krill, and mackerel are being overexploited by fishers, to the detriment of the Southern Ocean ecosystem, including local fauna, such as whales and native seabirds.” Dr. Brooks pointed to direct competition between the krill fishery, which, in 2021, killed three juvenile humpback whales, along with 16 seals, and 59 seabirds over the last two seasons.
The researchers noted that the Southern Ocean suffers major stressors from climate change. Sea ice is melting at alarming rates and ocean acidification and rising temperatures are pushing stocks into other zones, which has allowed for fishing all year round. Fishing at current levels will likely exacerbate environmental impacts on toothfish and Antarctic krill, along with the greater Southern Ocean ecosystem, including competing birds and mammals. Finally, krill’s crucial role in ecosystem and biogeochemical cycles means that impacts to their population is predicted to negatively impact Southern Ocean ecosystem services, including reducing the carbon storage by krill and drawdown of carbon and nutrients to the seafloor by whales.
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University of British Columbia (via EurekAlert!), 20 October 2022. Press release.
