Krill: how a tiny marine creature is forcing a big re-think of remote ecosystem

Krill have astonished scientists by being found swimming, eating and breeding in huge numbers many thousands of feet deeper than it was thought possible.
The discovery is forcing scientists to reassess their understanding of the creature and has highlighted just how little is known of the remote ecosystem.
Krill form a major source of food for whales, penguins, seals and squid in the Antarctic but had long been thought to survive only in the upper 500 feet of water.
A robot submarine sent by scientists to investigate life in an Antarctic abyss sent back pictures of krill feeding and ready to spawn in large numbers at 10,000 feet beneath the surface. Smaller quantities were found as far down as 11,500 feet.
“The new findings revise significantly our understanding of the depth distribution and ecology of Antarctic krill,” said Professor Andrew Clarke, of the British Antarctic Survey.
“It was a surprise to observe actively-feeding adult krill, including females that were apparently ready to spawn, close to the seabed in deep water.
“The behaviour of marine organisms - even quite ‘primitive’ ones - can be complex and more varied than we usually assume. There is still a great deal to learn about the deep sea and an important role for exploration in our attempts to understand the world we live in.”
Krill were recorded by the robotic craft engaged in nose-diving into the sediment of the seabed and then filtering the plume of dirt for nutients.
The deepwater discovery of Antarctic krill, Euphausia superba, by researchers from BAS and the National Oceanography Centre, in Southampton, was reported in the journal Current Biology.