Are the Q10values of more than 1,000 reported for Antarctic seabed fauna realistic?

Abstract

In a recent paper in Current Biology, Ashton et al.[1] describe the results of what they call the first ever experiment in which benthic assemblages are warmed to ecologically relevant levels in situ. West of the Antarctic peninsula, the authors employed heated settlement panels and studied the settlement and growth of pioneering species over a 5-month period at ambient temperature and at 1°C and 2°C above ambient. Such ocean temperature increases are expected within the next 50-100 years. They claim that the two most dominant species doubled their growth rate already at an increase of 1°C. They further state that this implies Q₁₀ coefficients around 1,000, which is much higher than anticipated. This unpredicted result should, according to the authors, critically change our thinking of how polar communities might respond to ocean warming. Indeed, such extreme Q₁₀ coefficients are a surprising result, and not in accordance with more than a century of laboratory or field research in temperate zones. Here, I will show that the claim is unsubstantiated and that the observed in situ growth-rate response to temperature of these Antarctic species is much weaker than claimed, and not very different from previous work in the temperate zone.