An IDEAL Center investigation revealed that amphipods – small crustaceans living in coastal areas – may not survive an increase in temperature.

Amphipods are small crustaceans known as scuds or, locally, as pulgas de mar.

Lorenzo Palma, IDEAL Center. Experiments at the Research Center Dynamics of High Latitude Marine Ecosystems (IDEAL) of the Universidad Austral de Chile revealed that, in Antarctica, amphipods (commonly known as scuds and locally as pulgas de mar), whose importance is fundamental to the diet of Antarctic fish, may not adapt to global climate change.

The research was developed within the framework of the Antarctic Scientific Expedition (ECA) 54 and was headed up by Dr. Kurt Paschke, a researcher at the IDEAL Center and an academic at the Institute of Aquaculture, Universidad Austral de Chile (UACh). The research team further consisted of Dr. Luis Vargas-Chacoff (researcher), Alejandro Ortiz (research assistant), and Julia Saravia (Doctoral student in Aquaculture Sciences, UACh).

In order to determine the fragility of amphipods in the face of global climate change and determine the repercussions on other Antarctic species, the research team carried out experiments subjecting amphipods to different temperatures.

“Amphipods are crustaceans that live around stones, rocks, and algae. Melting ice exposes them to a change in the salinity of the water they live in,” explains Dr. Paschke.

The IDEAL Center team chose Gondogeneia antarctica for the experiments. These amphipods play a key role in the White Continent’s food chain. The amphipods were collected in Fildes Bay, then exposed to temperatures of 2°, 5°, and 8°C. The amphipods experienced increased metabolism at 5° and 8°C, indicating highly stressful conditions. None of the amphipods survived a full day at temperatures of 11°C.

The research group also compared crustaceans and Antarctic fish. “The amphipods were more sensitive than the fish, particularly more than Harpagifer antarcticus, their main predator,” Dr. Paschke says. He further notes that, whereas the fish could tolerate temperatures as high as 11°C for ten days, none of the amphipods survived that temperature for a full day.

Furthermore, a combination of low salinity and high temperature affected the species considerably. Increases in temperature, melting ice, and freshwater inputs would be fatal for these small animals.

Finally, the upper trophic levels of the Antarctic systems could also be affected. Predators that feed on these amphipods may struggle more due to global change. Indeed, they may need to look for other sources of food.