Differing temperature regimes have no impact on the heat stress response of shallow and upper mesophotic populations of a temperate calcareous sponge

Marine heatwaves (MHWs) are increasing in intensity and frequency globally due to anthropogenic climate change. Temperate mesophotic ecosystems (TMEs) are light-dependent habitats found at depths of approximately 30–150m, between shallow euphotic zones and the deep sea. TMEs typically experience lower, more stable temperatures than adjacent shallow ecosystems, which may result in intraspecific differences in thermal tolerance between populations. Sponges, often the dominant benthic organisms in TMEs, display varied responses to thermal stress. We hypothesised that shallow-water sponges may be more resilient to heat stress than those from adjacent upper-mesophotic zones. Here we have deposited all data and code used in the analysis for this study.