Overfishing of Krill Threatens Ocean Ecosystem
Published: May 25, 2008
International Herald Tribune
SINGAPORE: In the global rush for resources, a tiny pink crustacean living in the seas around Antarctica is testing man's ability to manage one of the last great fisheries in the world without damaging the environment.
Krill, which grow to about six centimeters, or two inches, occurs in vast schools and is the major source of food for whales, seals, penguins and sea birds. Without it, scientists say, the ecosystem in and around Antarctica could collapse.
But krill is rich in oil brimming in omega-3 fatty acids that Norwegian and Canadian companies sell in pills. The crustaceans are also harvested for special enzymes that can be used by surgeons to clean wounds, even to clean contact lenses.
And the pinkish remains after processing can be used as fish meal, for example to give salmon flesh a richer pink color.
So far, difficulties in processing krill on ships, high fuel prices and the expense of sending fleets to the bottom of the globe has kept a lid on annual catches, which remain far below levels set under a treaty governing Antarctic marine life.
But the economic equation is changing fast, scientists and fishery regulators say, because of soaring food prices, falling global fish stocks and better ship-based processing technology.
Within five years, the annual krill catch could jump from just more than 100,000 tons to several million tons.
"The potential of the krill story is that the competition for protein of whatever form is becoming more and more acute," said Denzil Miller, executive secretary of the Commission for the Conservation of Antarctic Marine Living Resources, based in Hobart, Australia.
"I think in the next two to three years we are going to see a lot of changes in the way governments and the international community addresses problems of expectation around food security."
He said the commission had created guidelines that managed how and where krill were caught to try to minimize the impact on whales, seals and other predators. The idea is to spread out the catch once it reaches a certain size, particularly in the south Atlantic, where the bulk of the krill fishing occurs.
Failure to do so could have disastrous consequences, he said. Krill catches are already rising quickly.
"The most recent total notified catch was about 684,000 tons for the year 2007/08," Miller said, referring to the period from December to November. "That's all the countries that have notified, about 25 vessels from seven members of the commission and two nonmembers."
While it is still unclear whether 684,000 tons will be taken during the 2007/08 fishing season, the figure presents a sharp jump from 109,000 tons caught the previous season but still way below the total allowed catch of six million tons set under commission rules.
But new processing techniques by the Norwegian company Aker BioMarine have recently changed the whole krill fishery, scientists and environmentalists say.
The company has created a new way to harvest and process krill continuously. Previously, it was hard to catch and then later process large amounts of krill because the enzymes inside them break down quickly, spoiling much of the catch.
"The upshot of all this is that instead of one fleet catching 100,000 tons in a season, one boat can catch 100,000 tons in one season," said Gerry Leape, director of the Antarctic Krill Conservation Project.
"All of a sudden if that technology is replicated, you could go from a conservative catch to something that could start being a problem. We are not against krill fishing. We're just against an explosion of it that will not only jeopardize the krill but also have the impacts on the predators and not take into the necessary changes that will be caused by climate change."
Aker BioMarine says it cooperates with the global environmental group WWF to ensure that its krill-harvesting methods are sustainable.
The company also says it wants to increase production of its krill products, including krill oil and krill meal, and is building a high-tech harvesting and processing vessel to go into service in 2009.
The problem with krill, though, is that there are a lot of unknowns. Scientists say no one really knows how abundant krill are, with estimates of 200 million tons to 500 million. And no one really knows the exact numbers of whales, seals and penguins that rely on krill or how climate change will affect those populations or krill numbers.
Krill rely heavily on sea ice for breeding and feeding, particularly during winter months. They eat tiny phytoplankton that thrive on the underside of sea ice but global warming is changing the amount of sea ice down south, particularly around the Antarctic Peninsula, where temperatures have risen sharply in recent years.
In Hobart, Andrew Constable, part of the Antarctic Marine Ecosystems Program of the Australian Antarctic Division and the Cooperative Research Center for Antarctic Climate and Ecosystems, is leading a project to create a management program that will help fishing companies adapt to changing conditions in the Antarctic ecosystem.
"There are a number of different elements to consider with krill," he said. "One is the food web function and being confident the food web can be self-sustaining in the future and not impact on the recovery of whales. How do we make sure that the recovery of whales is not going to be jeopardized by krill fishing because they are going to be targeting the same locations that the krill fishers will."
One idea was to learn by a structured fishing approach.
"You actually have fishing in one location and not in another and you can compare the two to see what effect the fishery might have," Constable said.
"And can you arrange the fishery in such a way that you have a mosaic of areas where they fish and a mosaic of areas where they are not fishing and you measure a few key parameters in each of those areas. You can then start to tease out 'this is how we think the system works."'
And on top of all that, scientists needed to know what impact climate change will have.
"That's another reason I think we need areas which are closed to fishing so we can tease out what the effects of climate change might be from the effects of fishing," Constable said.
Steve Nicol, a krill expert, said it was crucial for any management tool to be very conservative.
"When you calculate how much krill it's safe to take, you put an awful lot of precaution in every aspect of the modeling you use to do it," said Nicol, program leader of the Southern Ocean Ecosystems Group at the Australian Antarctic Division in Hobart.
He also said with grain prices rising, krill could soon become economic to catch as fish meal.
"The supply of fish meal has gone right down, so you are actually getting a double whammy on fish meal and the cost of what people are prepared to pay for good-quality fish meal is going up all the time," Nicol said.
"At some point it's going to become economic to go fishing for krill just as a fish meal product."
Miller, the commission executive secretary, said that krill was already part of the bigger picture of global food security and that a strong management system was crucial for Antarctica's future.
"We've got to get this one right," he said, "because if we don't there's a whole lot of dominoes that follow afterwards that just looks too horrendous to contemplate.