Warming Antarctic Seas Could Place Krill and Food Chain at Risk

Krill play a major role in the Antarctic ecosystem. They provide food for all sorts of species of whales, seals penguin and fish. Yet as the climate changes, these creatures may be under threat. That's why scientists took a closer look at how temperature might affect krill.

Krill are known to be sensitive to sea temperature, especially in the areas where they grow as adults. In their early life stages, krill require deep water with low acidity and a narrow range of temperatures for their eggs to successfully hatch and develop. The larvae then feed on algae on the underside of sea ice. In order to successfully grow and reproduce, the adults need suitable temperatures.

In order to find out a little bit more about how climate change could impact krill, the researchers used statistical models. This allowed them to assess the likely impact of projected temperature increases in the Weddell Sea, Scotia Sea and Southern Drake Passage, which is known for its abundance of krill.

So what did they find? It turns out that if warming continues, the area of growth habitat could be reduced by as much as 20 percent. Yet this reduction in krill habitat isn't evenly spread. For example, the island of South Georgia could experience a reduction by as much as 55 percent. Housing a large range of animals that include fur seals and macaroni penguins, this reduction in krill habitat could largely impact these creatures further up the food chain.

"Each year, growth of Antarctic krill in the Southern Ocean produces new material that weighs twice as much as all the sugar produced in the world," said Simeon Hill, the lead author of the new study, in a news release. "Krill grow fastest in cold water and any warming can slow down or stop growth, reducing the food available for wildlife. Our research suggests that expected warming this century could severely reduce the area in which krill can successfully grow."

The findings are published in the journal PLOS One.