Polar Ecosystems Affected Differently by Climate Change

The biodiversity of polar ecosystems in the Arctic and the Antarctic might be affected differently as temperatures raise.

This is the main conclusion of a study published in the latest issue of the journal Marine Ecology Progress Series, conducted by scientists from The University of Western Australia’s Oceans Institute together with a team from the Spanish National Research Council (CSIC).

The researchers analysed the feeding relationships between more than 700 species- 145 are common for the Arctic ecosystem, while the remaining 586 belong to the Antarctic. They found that the Arctic was much more susceptible to climate change, because it had larger population of predators such as polar bears and whales, compared to the number of smaller species. The Arctic was also found to have almost double the number of omnivorous species.

The phenomenon, which describes the way the interactions between species will be disturbed, is known as “trophic cascade.” This explains how smaller species are much likely to get affected by the decreasing predators populations.

On the other hand, the Antarctic has larger population of prey species. To describe this relationship, the researchers use an example of the Antarctic krill, which population is found to decrease due to overfishing and climate change.

According to Professor Carlos Duarte, the director of the Oceans institute at the University of Western Australia, the study reveals that here are distinctive elements in the polar ecosystems, relative to non-polar food webs, which show that polar species, especially these in the Arctic, are highly vulnerable. If these species are lost, an invasion by other species is inevitable.

The two polar regions experience the strongest climate change. It is noted that for the Arctic and Antarctic Peninsula, the increase in temperature since 1950 is around 1.5ºC , compared to the 0.5ºC elsewhere in the world.