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.
“Antarctic fish have been easily overexploited, and many of these fisheries continue to be economically viable only on account of government subsidies which, as has been shown, contribute to overfishing,” said senior author Dr. Rashid Sumaila, professor at the UBC Institute for the Oceans and Fisheries (IOF) and the school of global affairs and public policy. “The remoteness of the Antarctic means that fuel use is high, leaving a disproportionate carbon footprint for fishing. Further, some fisheries are still targeted by illegal, unregulated, and unreported fisheries.”
The researchers highlighted their support of several recommendations that have already been made to CCAMLR, including a suite of science-based tools for managing marine systems for ecological and climate resilience.
“The Southern Ocean should be valued beyond its extractive value,” said co-author Dr. Louise Teh, IOF research associate. “Comprehensively mapping and then assessing the area in terms of ecosystem services should be done. It is important to evaluate this international zone in terms of social perceptions from stakeholders and all non-monetary values, including the significance of its marine mammals and birds, its role in our earth systems, its value as a global wilderness, and its contribution to peace and science.”
“Both current and future generations would suffer greatly if this area continues to be misused. Prioritizing conservation into CCAMLR values, management, and trade-offs in tandem with the wider Antarctic Treaty System, which is included in the CCAMLR Convention is necessary,” agreed Dr. Sumaila.
“The CCAMLR, during its meetings taking place this week and next, should push more forceful approaches to protecting this highly important and vulnerable area. This includes introducing more stringent catch limits, and expanding the current Ross Sea marine protected area to an ecologically representative network of Southern Ocean MPAs. A complete moratorium on finfish fishing may even be required if the species in the Antarctic Peninsula region continue to be vulnerable: unable to combat climate change or rebuild their stocks due to the overfishing pressure.”
“Protect global values of the Southern Ocean ecosystem,” was published in Science today.