Effects of ocean acidification on acid-base physiology, skeleton properties, and metal contamination in two echinoderms from vent sites in Deception Island, Antarctica

Antarctic surface waters are expected to be the first experience severe ocean acidification (OA) with carbonate undersaturation and large decreases in pH forecasted before end of this century. Due long stability environmental conditions relatively low daily seasonal variations which they exposed, marine organisms, especially those a supposedly poor machinery eliminate CO2 protons heavily calcified skeleton like echinoderms, hypothesized as highly vulnerable these shifts. The opportunities offered by natural gradient generated vent activities Deception Island caldera, Western Peninsula, were used investigate for time acid-base physiologies, impact OA on metal accumulation sea star Odontaster validus urchin Sterechinus neumayeri. two species sampled four stations within at (total scale) 8.0–8.1 reduced 7.8. Measured variables pH, alkalinity, dissolved inorganic carbon coelomic fluid; characteristic fracture force, stress Young's modulus using Weibull statistics Cd, Cu, Fe, Pb Zn concentrations integument, gonads digestive system. Recorded characteristics both studied fit general picture deduced from temperate tropical stars urchins but possibly confounding factors, principally food availability quality, prevented definitive conclusions. Reduced seawater 7.8 metals had almost no mechanical properties investigated despite very high Cd O. integument. was correlated increased contamination most relation weak. Translocation caging experiments taking into account parameters proposed better understand future processes linked echinoderms.