Meeting Abstract
Recolonisation of the deep-sea by shallow water organisms following catastrophic climatic event has taken place on several occasions of the geological past. At shorter time scale, a shift in the distribution of species is of great importance as a response for species facing climate change. Many studies have focussed on the capacity of marine ectotherms to shift their ranges latitudinally in response to current ocean-surface warming. Bathymetric range shifts offer an important alternative; yet hardly any relevant data exist. Hydrostatic pressure (HP) and temperature have wide ranging effects on physiology, importantly acting in synergy thermodynamically, and therefore represent key environmental constraints to bathymetric migration. Here, I synthesise data from recent studies on the thermal scope, thermal and hydrostatic pressure acclimation, and transcriptional regulation in a shallow-water marine crustacean (Palaemon varians) to establish the potential physiological limit to bathymetric migration by shallow-water fauna. Observed changes in gene expression are indicative of cellular macromolecular damage, disturbances in metabolic pathways, and a lack of acclimation after prolonged exposure to high HP. These effects appear less deleterious at higher temperatures, and are exacerbated at lower temperatures. These data have important implications for our understanding of the potential for marine ectotherms to undergo climate-driven bathymetric range shifts.
