Issues
Increasing Demand for Krill
Aquaculture
The greatest demand today for Antarctic krill comes from the aquaculture industry, which is literally running out of food to sustain its rapid growth. According to the industry's own sources, fish farming already uses about 75 % of the world's fish oil and 40 % of its fish meal — numbers that could reach 79 % and 48 % respectively by the end of this decade.
Many of the fish species historically harvested by aquaculture for fish oil and meal, such as Peruvian anchoveta are already fully exploited with their harvests capped in many areas. Krill oil and meal appear to be the perfect alternative. They are very high in protein and essential amino acids. Krill oil and meal also have lower levels of pollutants than other sources of fish oil and meal. In addition, they are especially desirable feed for salmon aquaculture because their natural pigment gives these fish their trademark "pink" color.
Medical and Cosmetic Uses
Krill oil has high concentrations of Omega-3 fatty acids that are increasingly marketed as dietary supplements for cardiovascular health and longevity. Krill oil is promoted as a more powerful antioxidant than other fish oils, with lower levels of contaminants. Similarly, some experts now promote krill for pharmaceutical uses such as post-surgical healing and treating high cholesterol.
Technology of Fishery
Krill's behavior has always made them easy to catch in large numbers. Swimming near the ocean's surface, swarms of krill are easy to spot. The giant aggregations of these tiny crustaceans are no match for today's state-of-the-art industrial trawlers. The latest generation of commercial vessel is literally a floating factory, employing sophisticated methods to land, process, and flash-freeze catch. Currently, one of these factory trawlers, the Saga Sea operated by the Norwegian multi-national corporation Aker ASA, has been outfitted with equipment that enables it to continuously vacuum millions of krill from the ocean, harvesting as much as 120,000 tonnes in a single fishing season.
Only Aker uses this technology at the moment, but other vessel owners and national authorities are keen on adopting it. The use of this technology could significantly increase the amount of krill harvested in a given year. Norwegian officials are monitoring these operations. Nevertheless, there is a potential for a dramatic increase in overall krill catch with this new technology. This development is of special concern because the fishery operates in small areas overlapping with important foraging grounds for penguins and seals that depend on krill to feed their young.
Increasing Environmental Pressure
Climate Change
As a result of climate change, Antarctica has seen significant temperature increases over the past 30 years. With fewer months of winter sea-ice coverage, krill spawning and nursery areas are decreasing. The Antarctic management regimes must consider the effects of climate change on the overall ecosystem, with protections for all of its inhabitants.
Krill reproduction depends on sea-ice conditions. The longer the winter sea-ice lasts and the larger area of the ocean it covers, the more successful the krill spawning season. This probably relates to the availability of ice-algae, which grows on the underside of the sea-ice and is an important food source for krill in the winter. Scientists have found that in winters with shorter and smaller sea-ice coverage, krill reproduction is reduced.
Surprisingly, krill behavior may help reduce climate change. Recent research has discovered that these tiny creatures help reduce greenhouse gases by sequestering carbon dioxide. These crustaceans rise to the surface where they eat phytoplankton, taking in large amounts of carbon dioxide (CO2). During feeding, krill periodically dive to great depths, releasing carbon into the deep sea. One study estimates the amount of CO2 ultimately transferred to the ocean floor by millions of krill equals the annual emissions of 35 million automobiles.
The Antarctic Peninsula region is highly vulnerable to a warming planet, while the waters surrounding the peninsula are one of the most important spawning and feeding grounds for Antarctic krill. This area also has the highest abundance of land-based krill predators (penguins and seals) in the Southern Ocean. The reduction in Antarctic sea ice currently occurring in this region negatively affects krill populations in multiple ways, including decreased reproductive output and recruitment success, increased depredation of krill by land-based predators, and increased pressure on krill stocks from industrial fishing fleets. Due to the reductions in sea ice over the past two decades, the krill fishing fleet and land-based predators are both able to take krill for a longer part of the year. The direct impacts that a changing climate have on the Antarctic krill fishery must be taken into account in order to develop an effective management plan for this important species and the ecosystem as a whole. (Kawaguchi et al, 2009)
© Pew Environment Group
-->Icescape photo courtesy U.S. Antarctic Program
Krill Library-->
Monday, 11 October 2010
The Antarctic Krill Conservation Project: The Issue
via krillcount.org
