Antarctic Krill Move Southwards Amid Increasing Temperatures
Due to conditions created by global warming, it would seem that the Antarctic krill are moving en masse in a southward direction in order to escape the warmer waters. According to scientists, over the past 90 years, krill have progressively been moving from the Southern Ocean toward the Antarctic continent by roughly 270 miles.
Scientists from the Plymouth Marine Laboratory and the British Antarctic Survey have come together to compile data from the Scotia Sea and the Antarctic Peninsula, which traces back all the way to the 1920s. Their findings suggest that krill numbers and dispersal began shifting from the 1980s. Coincidentally, this lines up with the Southern Annular Mode or the north-south movement of the wind belt circling Antarctica.
This change led to a decrease in sea ice and an increase in warmer weather conditions. While such conditions make it easier for larval krill to hatch, they unfortunately make it difficult for them to survive. This is because the larval krill use sea ice to shelter themselves and feed on the algae that grow in the nooks of ice. Krill have also become much bigger in terms of length in recent times because the species is increasingly dominated by older members.
According to the scientists, there are fewer krill and most of them aren’t even found in their natural habitat. Their exact quote reads: “Our results suggest that over the past 40 years, the amount of krill has, on average, gone down, and also the location of the krill has contracted to much less of the habitat.”
It’s extremely concerning that krill are moving away from their natural habitat as they’re a staple fixture in the diets of various marine life in the area, such as seabirds, penguins, and whales. As it is, these species find themselves endangered due to a myriad of reasons, but those factors are compounded by the fact that their food source’s population seems to be declining.
Even now, there is evidence to support the fact that macaroni penguins and fur seals are competing with each other to secure krill in order to sustain their numbers. With the number of krill being on the decline, this competitive spirit is likely to extend to all species that rely on krill for nourishment.
Due to these concerns, scientists have stated that some action needs to be taken or else the marine ecosystems are going to experience negative impacts. They also acknowledge the need for global action to contend with climate change, as managing krill fishery is limited in its helpfulness.