Gondogeneia antarctica. (Photo: IDEAL)

Sand fleas may not adapt to temperature increase in Antarctica

CHILE
Thursday, August 16, 2018, 00:10 (GMT + 9)

An investigation by the Centre for the Dynamic Investigation of Marine Ecosystems of High Latitudes (IDEAL) reveals that amphipods, small crustaceans that live in coastal areas, would not survive an increase in temperatures. And it warns that this could affect their predators, who would be forced to look for new foods.

Experiments carried out by scientists from the IDEAL Centre of the Austral University of Chile revealed that, in Antarctica, amphipods - commonly known as sand fleas and whose importance is fundamental to the diet of Antarctic fish - may not adapt to global change.

The research, which was developed within the framework of the Antarctic Scientific Expedition (ECA) 54, was led by IDEAL Centre researcher and academic from the Institute of Aquaculture of the Universidad Austral de Chile Dr. Kurt Paschke.

With the objective of studying the fragility with which these crustaceans face the global change and the repercussions that it can have for other Antarctic species, Dr. Paschke, together with the researcher Dr. Luis Vargas-Chacoff, the research assistant Alejandro Ortiz and the student of the Doctorate in Aquaculture Sciences of the UACh Julia Saravia, carried out experiments where they subjected the amphipods to different temperatures.

"The amphipods are crustaceans that live associated with stones, rocks and algae. When the ice melts, they are exposed to a change in the salinity of the water they live in," explains Dr. Paschke.

For the experiments, the IDEAL Centre team worked with Gondogeneia antarctica, amphipods that play a key role in the trophic plots of the white continent, as they are prey to various animals. After being collected at Bahía Fildes, the crustaceans were exposed to temperatures of 2, 5 and 8 °C. At temperatures ranging between 5 and 8 °C, the increase in metabolism indicated highly stressful conditions, whereas when subjected to a temperature of 11 degrees Celsius, none survived a full day.

The working group also made a comparison between crustaceans and Antarctic fish.

"Amphipods were more sensitive than fish, particularly the Harpagifer antarcticus, their main predator," says Dr. Paschke, adding that the fish tolerated up to 11 °C for ten days. However, all amphipods died by subjecting them to that temperature.

At the same time, the researchers detected that the combination of low salinity and high temperature affects the species considerably. Conditions of temperature increase, ice melt and freshwater intake would be lapidary for small animals.

As a consequence of the above, the upper trophic webs of the Antarctic systems could also be affected. Predators that feed on these amphipods may also have more problems with global change, and may be in need of other food.

editorial@seafood.media
www.seafood.media

Print