21 Oct 2019
WHALES, PENGUINS AND KRILL FEELING THE HEAT IN ANTARCTICA
A new report by the World Wide Fund for Nature (WWF) highlights that human-caused warming is destroying sea ice habitat in the Antarctic, threatening the survival of many iconic polar species such as whales, penguins and krill.
The report Tracking Antarctica: Responding to the Climate Crisis has been released as the annual meeting of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) gets underway in Hobart.
WWF is urging CCAMLR to deliver a network of marine protected areas to reduce pressure on the region's wildlife and give it time and space to adapt.
Ocean temperatures in West Antarctica along the Antarctic Peninsula have risen by more than 2.7°C since the 1970s—about five times the global rate of warming.
The Antarctic Peninsula is a hotspot of environmental change, with almost 90% of the western peninsula’s 674 glaciers receding since the 1940s.
Antarctic ice shelves have shrunk in size by almost one quarter since the 1950s and the continent has lost 3 trillion tonnes of ice since 1992.
Melting sea ice poses a grave threat to krill which feed on phytoplankton growing beneath the ice.
Krill, a key species in the Antarctic food web, are contracting southward by as much as 440 km (4 degrees latitude) as their suitable habitat recedes due to climate change along the Peninsula and Scotia Sea.
This shift in krill distribution is likely to drain energy from migrating whales, with effects on body condition, reproductive fitness and population abundance.
“With key feeding areas of whales, and other krill predators such as penguins, seals and seabirds, increasingly overlapping with commercial krill fishing, it means Antarctica’s iconic wildlife is under increasing pressure,” said Chris Johnson, Senior Manager, WWF Antarctic Program.
In 2018 the industry caught 312,989 tonnes of krill in the Southern Ocean —the largest catch recorded since 1991.
The duration of sea ice cover has decreased by 85 days in the Western Antarctic Peninsula, resulting in population declines for sea ice-dependent Adélie and chinstrap penguins.
Similarly, emperor penguins in the Weddell Sea have experienced multi-year breeding failures due to melting sea ice.
Climate models of diminishing sea ice predict that emperor penguins are facing population decreases of between 40% and 99% by the end of the century.
High densities of Antarctic minke whales occur near the edges of seasonal sea ice, where they are more protected from open-water predators, such as Type A killer whales.
Recent studies found that Antarctic minke populations may also be declining as a result of reduced seasonal sea ice and further forecasted sea ice changes could heavily impact the species.
“Antarctica may seem remote but the science is clear where climate change is threatening the stability of marine ecosystems that are undergoing a rapid, unprecedented transformation,” said Mr Johnson.
“Protecting nature is part of the solution to fight back. As governments around the world are making commitments to fight climate change at home, this year we can deliver on commitments to establish networks of marine protected areas around Antarctica – creating a safety net for wildlife. We are at a critical crossroads.
“We can provide space for nature to adapt to current and projected changes, safeguarding Earth’s biodiversity for future generations.
“Last week, Australia’s Environment Minister Sussan Ley publicly endorsed the East Antarctica Marine Protected Area proposal. It will protect a huge area of ocean the size of South Australia (1mil sq. km). Global leaders now have the opportunity to step up and respond,” he said.