Fri, Nov 03, 2006 - Page 9 News List

The cost of killing krill

A tiny crustacean crucial to the Antarctic marine food chain is in danger of being overfished - to the detriment of other sea life

By Virginia Gascon Gonzalez and Rodolfo Werner Kinkelin

A recent report by the UN Food and Agriculture Organization found that almost half of all fish eaten worldwide are raised on fish farms rather than caught in the wild. It is likely that consumption of no other fish has soared more than that of farmed salmon, with production surging by almost 300 percent in 20 years.

Salmon are carnivorous, however, and to feed the voracious appetite of these legions of farm-raised fish, the aquaculture industry increasingly has turned its attention to a small crustacean commonly known as Antarctic krill. But that's bad news for leopard seals and Adelie penguins, humpback and blue whales, and many other species, because most organisms in the Antarctic marine ecosystem eat either krill or something that eats krill.

Found in the cold waters of the Southern Ocean, krill constitute a key ingredient in fish oil and feed. Unfortunately, recent research indicates that expanded krill fishing might put the Antarctic ecosystem at risk. Representatives from the world's major fishing nations, meeting this fall in Australia, have an opportunity to limit krill catches, thereby helping creatures that need krill to survive.

Although each krill may only grow to weigh about 2g, together they constitute one of the most abundant animal species on Earth. Indeed, krill form the largest known aggregation of marine life, with a biomass perhaps greater than any other multicellular animal organism on the planet.

This "pink gold" forms the heart of the Antarctic marine food web, and land-based krill predators, such as penguins and seals, are most vulnerable to krill scarcity. Scientists have found that demand for krill has begun to exceed supply in some areas of the Southwest Atlantic. As a result, penguins and albatrosses already experience difficulty rearing their offspring in areas such as South Georgia. And yet krill fishing is projected to grow.

The Southern Ocean contains the largest population of krill in the world. As krill tend to aggregate in concentrated swarms, they are easy to catch and have become particularly attractive to large-scale commercial interests.

Moreover, krill fishing has recently been fueled by new technological advances such as vacuum pumps, which allow a single fishing vessel to catch and process huge amounts -- up to 120,000 tonnes per season.

Furthermore, demand for krill products -- from fish oil and feed to skin creams and other cosmetics -- has increased over the past 20 years. As wild fish populations continue to decrease, in tandem with an ever-growing global appetite for seafood, the pressure on the aquaculture industry for fish feed will skyrocket. The increased demand for krill, along with the new catching and processing capabilities, has combined in a way that the Antarctic ecosystem might not be able to withstand.

But there is hope. The Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) was established in 1982, as part of the Antarctic Treaty System, in response to concerns that continued unregulated fishing might undermine the basis of the Antarctic food chain. The CCAMLR is governed by a commission of 24 member states -- including Argentina, Australia, Chile, Japan, Norway, Russia, South Africa, South Korea, Ukraine, the US and the EU -- that meets annually in Hobart, Australia, to discuss new fishing regulations concerning marine species in the Southern Ocean.

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