Can seastars cope with predatory pressure in high CO2?

See our recent paper published in the peer-reviewed journal Marine Environmental Research:

McCarthy, I, Whiteley, N, Fernandez, WS, Ragagnin, MN, Cornwell, TO, Suckling, CC, Turra, A. Accepted. Elevated pCO2 does not impair performance in autotomized individuals of the intertidal predatory starfish Asterias rubens. Marine Environmental Research.

Abstract: The impacts of ocean acidification remain less well-studied in starfish compared to other echinoderm groups. This study examined the combined effects of elevated pCO₂ and arm regeneration on the performance of the intertidal predatory starfish Asterias rubens, as both are predicted to come at a cost to the individual. A two-way factorial experiment (∼400 μatm vs ∼1000 μatm; autotomised vs non-automised individuals) was used to examine growth rates, lipid content (pyloric caeca and gonads), and calcium content (body wall) in both intact and regenerating arms, as well as subsequent effects on rate of arm regeneration, righting time (behaviour) and mortality over 120 days. Autotomised individuals tended to show lower (not significant), survival and growth. Elevated pCO₂ had no effect on mortality, body growth, arm regeneration, righting time or arm calcium content. Lipid content was higher in the pyloric caeca, but not in the gonads, in response to elevated pCO₂ irrespective of autotomisation. The results of the study suggest that adult A. rubens remain unaffected by increased pCO₂ and/or arm autotomy for 120 days, although longer term experiments are necessary as the results indicated that survival, growth and calcification may be impaired with longer-term exposure to elevated pCO₂.