Krill, the tiny shrimp-like creatures have a great role in the Antarctic food chain. They are small crustaceans located in all the world’s oceans. The name krill originates from the Norwegian word which means ‘small fry of fish.’ It is also usually attributed to varieties of fish.
The tiny creatures are considered an essential trophic level link – near the ground of the food chain – because they feast on zooplankton and phytoplankton, transforming these into a form proper for many bigger creatures for whom krill makes up the greatest component of their diet.
As the climate change heats the Southern Ocean and changes sea ice patterns, the region of Antarctic water proper for the tiny creatures to hatch and develop could fall sharply.
Most of the Antarctic krill are located in an area from the Weddell Sea to the waters nearby the Antarctic Peninsula. Many species of whales, penguins and seals consider the tiny creatures an essential source of food.
In those areas, communities of adult Antarctic krill have decreased by 70 to 80 over the preceding 40 years.
Researchers are presently trying to find out if the decrease is due to a rebound in whale groups after the cessation of commercial whaling, the results of climate change or a combination of the two factors.
Scientists are worried about the consequences that coming climate change might have on the krill population and the greater Antarctic ecosystem.
The variations in ocean temperatures and sea ice coverage could affect krill through their earliest life steps when they are extremely exposed to environmental conditions.
The regimented life cycle that needs a delicate stability of conditions is very complex for the tiny creatures. The female lays eggs during summer in the upper ocean. The eggs then sink to the area of the ocean where is the temperature range for them to hatch. Once hatched, the larvae must return to the surface of the ocean where they need to find food within ten days, or they will die.
Whether phytoplankton populations would decrease or increase along with the warming is another unknown. The study shows that if they do lower, the higher that decline is, the more it will reduce krill populations.
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