Tiny krill moves big oceans

From the Australian Antarctic division:

Tiny swimmers stir oceans

Monday, 06 April 2009

Turbulence in the ocean, caused by the wind, tides and currents, plays an important role in regulating the global ocean circulation and the movement of gases and nutrients between the surface and deeper waters. Now new research suggests that organisms as small as krill can contribute to this turbulence.

According to Science magazine, scientists have hypothesised that schools of krill, which migrate up through the water column at night to feed, generate large turbulence patches, potentially increasing the nutrient exchange across the stratified (layered – with warmer water at the surface) ocean. This means that krill could be fertilising the surface waters, boosting the production of phytoplankton.

It’s not hard to imagine that large organisms, such as whales or big fish, could produce such ‘biologically generated turbulence‘ or ‘biomixing’ at a local scale. Indeed, scientists speculate that the removal of whales and stocks of big fish over the past 200 years could have removed enough biomixing to affect climate (through, for example, a change in the exchange of carbon dioxide between the atmosphere and the ocean). But the idea that krill could generate enough turbulence to efficiently mix ocean waters is controversial.

Research by the Australian Antarctic Division’s krill biologist, Dr So Kawaguchi, and his collaborators at the Georgia Institute of Technology in the United States, is lending weight to the hypothesis that biomixing by krill does occur.

A marine effect, somewhat similar to the butterfly effect, usually based on a tropical rainforest example. If small krill can influence the big oceans, then, maybe, watch out what this small blog might yet do ….

Krill prefer sex in the dark: here.

Krill ‘superswarm’ formation investigated: here.

First nearshore survey of Antarctic krill reveals high density, stable population in shallow waters: here.

This parasitic worm hitches a ride with krill into baleen whales, in which it develops into an adult: here.

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