Thermal responses of three native fishes from estuarine areas of the Beagle Channel, and their implications for climate change

LATTUCA, MARÍA EUGENIA; BOY, CLAUDIA CLEMENTINA; VANELLA, FABIÁN ALBERTO; BARRANTES, MARÍA EUGENIA; FERNÁNDEZ, DANIEL ALFREDO

HYDROBIOLOGIA

SPRINGER

Año: 2018 vol. 808 p. 235 - 249

0018-8158

The aim of this work was to analyze the thermal responses of Odontesthes nigricans, Eleginops maclovinus, and diadromous Galaxias maculatus, key species in estuarine areas of the Beagle Channel (Tierra del Fuego, Argentina), under a climate change scenario. We hypothesized that, in the southernmost limit of the species´ distribution, individuals are more likely to be affected by indirect consequences of climate change rather than direct temperature mortality. Their thermal tolerance limits were assessed using the Critical Thermal Methodology and their preferred temperatures, using a thermal gradient. Additionally, the Fulton´s condition factor and the energy density of individuals were analysed as a proxy of the condition of fishes acclimated to different temperatures. Results showed that species analysed have the ability to acclimate to the different temperatures, intermediate to large tolerance polygons and positive relationships between preferred and acclimation temperatures, indicating their eurithermic nature. Thus, O. nigricans, E. maclovinus and diadromous G. maculatus populations from Tierra del Fuego could experience enhanced performances because of moderate warming being and, as it was hypothesized, be influenced by indirect consequences of climate change (habitat degradation or changes in trophic structure) since they are living in environments that are widely cooler than their maximum tolerance.