Hot or not? The role of sea, air and sand temperatures in determining the range edge for a shore-dwelling decapod in a marine warming hotspot
David S Schoeman (1), Rod Connolly (2), Andrew Olds (1), Ben Gilby (1), Chantal Huijbers (1), Thomas A Schlacher (1)
1 School of Science & Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, Queensland 4558, Australia
2 Australian Rivers Institute – Coast & Estuaries, and School of Environment, Griffith University, Gold Coast, Queensland 4222, Australia
Recent studies have demonstrated that marine ectotherms are more likely than their terrestrial counterparts to fully occupy their fundamental niches. Moveover, traits of marine species, including dietary breadth, swimming ability and size of latitudinal range, have also been shown to enhance the rate of climate-driven range extension. This suggests that we have a good understanding of climate-mediated range shifts. Yet there are a few marine species for which range limits are precisely known, and fewer, still for which the effects of multiple temperature metrics on inferred opportunistically from time series that do not necessarily include observations at the range edge. And these range shifts tend to be quantified against metrics deprived from mean annual temperatures, which are not always representative of extremes or of other temperature studies of climate-change ecology; the ghost crab Ocypode cordimanus specifically, we track its poleward range edge over the period of three years and quantify the role of multiple metrics of air, sea and sediment temperatures in controlling the position of this range edge. Although this range edge is located in a marine warming hotspot, air, sea and sediment temperatures exhibit contrasting temporal patterns and sediment temperatures are also dependent on depth. Thus temperature control of the range edge is shown to be complex for this species, confounding simple predictions of poleward range extension.