After doing experiments in the white continent, a team of researchers from the IDEAL Center observed negative effects of temperature increase concerning the fish, Harpagifer antarcticus.
The Antarctic´s intertidal zone is one of the places where the Harpagifer fish inhabits. Photograph: Javier Arata.
Harpagifer antarcticus is the scientific name of the Antarctic spiny plunderfish, a fish that inhabits the Antarctica coast and nearby islands and has a high capacity to mimic between the rocks and substratum. It lacks commercial importance; however, it plays a crucial role in communities of small crustaceans that exist on the white continent.
During the first Antarctic campaign of the Research Center Dynamics of High Latitude Marine Ecosystems (IDEAL), researchers, Jorge Navarro, Luis Vargas and Kurt Paschke, from the University Austral of Chile, together with research assistant Alejandro Ortiz, studied what effect an increase in water temperature would have over the physiological response of this species. This investigation will help to better understand the role of this fish in the intertidal zone of Antarctica.
“Harpagifer is a predator of small crustaceans from the amphipods group that inhabit the intertidal zone of Antarctica and therefore, regulates the population of these invertebrates, that are very abundant in these areas”, explains Dr. Jorge Navarro.
The team hypothesized that: an increase in temperature in Antarctica, in the face of future global change scenarios, will have a negative effect on Harpagifer, affecting its physiological response. To test this, they conducted 10 days of experiments at the Escudero Base, belonging to the Chilean Antarctic Institute, in which the species was exposed to different temperatures, the scientists observed as immediate results, that this fish, which lives between 2° and 4° Celsius, when exposed to higher temperatures, shows the first negative signs at 8° C, with low mortality, which significantly increases ??over 30% of mortality values when exposed to 11° Celsius.
“We then subjected the species to an extreme temperature of 14° Celsius, where we could observe over 93% mortality during the experimental period,” says Dr. Navarro.
Scientists observed a mortality above 93% when the fish was subjected to extreme temperatures. Photograph: Jorge Navarro
The same experiment in Magallanes
The team of scientists will perform the same experiment with the fish, Harpagifer bispinis (Magellan plunderfish), which lives in the sub-Antarctic zone is closely related with Harpagifer antarticus.
“These studies will respond to two objectives of our research line within the IDEAL Center. The first is related to the ability of these two congeneric species to live in both geographic areas (Magellan and Antarctica), from the point of view of tolerance to temperature and depending on the connectivity that might exist between them two regions.
The second objective is to investigate how these two species react to future scenarios of global change, understanding that both in Magellan and Antarctica, temperatures are expected to increase during the present century”, concludes Dr. Navarro.