Research also rules out a possible migration of Harpagifer antarcticus to Chilean Patagonia, due to its intolerance to warmer temperatures.
Although there are already studies that confirm the low tolerance of H. antarcticus to environmental variables produced by climate change, a new study determined its osmoregulatory response at different levels of temperature and salinity. © Ignacio Garrido.
In ecological terms, Harpagifer antarcticus is a well-studied fish within the fauna of the white continent, due to its distribution on the coasts, its importance in the feeding of various organisms and its relationship with the Harpagifer bispinis, a species with similar characteristics that lives in the sub-Antarctic zone (Patagonia,) but of different physiology.
Although there are already studies that confirm the low tolerance of H. antarcticus to environmental variables produced by climate change, a new study determined its osmoregulatory response at different levels of temperature and salinity, showing how climate change affects its hydromineral balance.
The research was led by Dr. Luis Vargas-Chacoff, vice-rector for Research, Development and Artistic Creation of the Austral University of Chile (UACh) and researcher at the Center for Dynamic Research on Marine Ecosystems of High Latitude (IDEAL).
The specimens were exposed to variables such as temperature and salinity (2, 5, 8 and 11°C and 33, 28 and 23 psu,) evaluating changes in the branchial-renal-intestinal activity, the percentage of muscle water and plasma osmolality (solute concentration) in osmoregulatory responses, changes in their body that are also visible in their behavior, such as contractions, erratic swimming, and dehydration.
“Climate change projections indicate an increase in temperature and a drop in salinity due to freshening (fresh water entering the ocean.) If these variables occur abruptly, the animal is subjected to a double stressor, causing it to have serious adaptation problems,” explained the researcher.
The researchers from the IDEAL Center, doctors Kurt Pashcke and Jorge Navarro, who together have already published scientific papers related to the physiological response of H. antarcticus to climate change, also participated in the study.
“These results make it quite clear to us that the animal cannot live at less than 25 psu of salinity, nor at more than 8 degrees Celsius. The fish will be forced to seek deeper places; however, it will lose the ability to blend into the rocky area of the intertidal zone, making it an easy prey for species such as penguins, wolves and other fish,” commented Dr. Vargas-Chacoff.
The study, published in the scientific journal “Journal of Thermal Biology,” also ruled out a possible migration of H. antarcticus to the Magallanes Region, due to its inability to withstand temperatures above 5°C.