Data: Upper thermal limits and risk of mortality of coastal Antarctic ectotherms

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 (CTmax) is crucial to project the persistence and distribution
areas of the Antarctic marine species. Using thermal death time curves
(TDT), we estimated CTmax 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 CTmax at 1 min are far from the
temperature present in the marine intertidal area where our study species,
showing Echinoderm species higher CTmax 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 CTmax estimates, which deliver closer and more
realistic parameters according to the species that may be experiencing in
the field.