Global warming may kill Antarctic krill

From the Australian Antarctic Division:

Spring ice keeps krill alive

Wednesday, 03 September 2008

Researchers have found that spring-time growth of sea ice algae is critical to krill growth and reproductive potential.

This could mean that future changes in sea ice coverage could threaten the species, which plays a key role in the Southern Ocean food chain and is a source of nourishment for many whale species.

The Australian Antarctic Division measured krill populations during the annual formation and retreat of sea ice around Antarctica. Antarctic krill feed on ice algae during winter and spring, when food in the water column is scarce.

The researchers found that adult krill were just about to start boosting their maturity in preparation for summer reproduction, by utilising ice algae under ice floes as a food source, as well as phytoplankton blooms in areas where the ice had started to retreat. During the voyage krill larvae were also found to be on the verge of accelerating their growth rates, in preparation for summer.