AUTHOR=Carter Mauricio J. , García-Huidobro M. Roberto , Aldana Marcela , Rezende Enrico L. , Bozinovic Francisco , Galbán-Malagón Cristóbal , Pulgar José M. 

TITLE=Upper thermal limits and risk of mortality of coastal Antarctic ectotherms

JOURNAL=Frontiers in Marine Science

VOLUME=9

YEAR=2023

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.1108330

DOI=10.3389/fmars.2022.1108330

ISSN=2296-7745

ABSTRACT=<p>Antarctic marine animals face one of the most extreme thermal environments, characterized by a stable and narrow range of low seawater temperatures. At the same time, the Antarctic marine ecosystems are threatened by accelerated global warming. Determining the upper thermal limits (<italic>CT</italic><sub>max</sub>) is crucial to project the persistence and distribution areas of the Antarctic marine species. Using thermal death time curves (TDT), we estimated <italic>CT</italic><sub>max</sub> at different temporal scales from 1 minute to daily and seasonal, the predict vulnerability to the current thermal variation and two potential heatwave scenarios. Our results revealed that <italic>CT</italic><sub>max</sub> at 1 min are far from the temperature present in the marine intertidal area where our study species, showing Echinoderm species higher <italic>CT</italic><sub>max</sub> than the Chordata and Arthropods species. Simulations indicated that seasonal thermal variation from the intertidal zone contributed to basal mortality, which increased after considering moderate scenarios of heatwaves (+2°C) in the Shetland Archipelago intertidal zone. Our finding highlighted the relevance of including exposure time explicitly on the <italic>CT</italic><sub>max</sub> estimates, which deliver closer and more realistic parameters according to the species that may be experiencing in the field.</p>