‘Krill’ is the common term for the various species of crustacean which exist within the order Euphausiacea. They are similar to shrimp, and are very small – at their largest they are around two inches in size. Among the various species of krill, of which eighty-five are currently known, the most familiar and most abundant is the Antarctic krill (Euphausia superba). In recent years there has been a movement in some areas to restrict the term “krill” to this one species, although this has not been universally adopted.
The role of krill in the food chain
Krill form a vital link in the food chains of marine ecosystems, serving as the primary form of prey for various species of fish, squid, seabird and aquatic mammal. Some animals, such as the blue whale, live almost exclusively on krill.
The animals gather together in swarms, sometimes so tightly packed together that shoals of krill can be visible from the air; it is because of this that they can provide adequate food supplies to large animals such as whales despite their small size.
Human consumption of krill
Although krill are not currently as popular as a form of seafood in the Western world as shrimp or prawns, they are eaten in various countries including Japan and Russia. More recently, krill oil has become available on the market as a dietary supplement due to its high quantities of omega-3 acids.
The U.N.’s Food and Agriculture Organization has also pointed to krill as a species which could potentially be harvested to deal with the serious problem of potential food shortages in the future.
This claim has sparked apprehension in certain quarters. Due to their important place in the food chain, there has been concern that extensive harvesting krill could lead to a major depletion of the quantities living in the sea, thereby disrupting entire ecosystems as other varieties of aquatic life are robbed of their main source of food.
Sustainable fishing of krill
Because of the concerns noted above, it is important that serious thought and research is put into sustainability when it comes to fishing krill so as to prevent over-harvesting.
For one thing, it is worth remembering just how many krill there currently are in the sea. According to studies, the current combined biomass of Antarctic krill is around 420 million tonnes; current krill harvesting, meanwhile, has taken in less than 150,000 tonnes a year from 2002 to 2007. This is clearly a sustainable amount, although there may still be problems if harvesting were to rise in scale according to the above proposal from the Food and Agriculture Organization.
Currently, krill fishing in the Southern Ocean is overseen by the Commission for the Conservation of Antarctic Marine Living Resources. If society is to begin harvesting krill for everything from dietary supplements to a solution for world hunger, then adequate measures need to be taken in the present day to ensure that the animal is not over-fished. At the moment, there is little sign of any major problems, with current krill fishing contained within sustainable levels and overseen by dedicated bodies. But history has shown us that humanity can have a disastrous impact on the natural world; it is vital that we learn from our mistakes and proceed with caution as we adapt to the world of the future.
Sustainable Eco Harvesting:Superba Krill Oil from Aker Biomarine
Gary Bale writes on a range of topics relating to ecology, sustainability and the environment.