Impacts of Short-Term Large-Scale Climatic Variation on Sponge Assemblages

There are large-scale processes that are impacting marine communities across the world at a range of temporal scales. In this chapter, we consider the potential impacts of short-term, large-scale, climate processes on sponges with a major focus on temperature variation. We examined available case studies from across the world to assess the physiological and ecological impacts of such temperature anomalies. Sponges show a number of responses to temperature including changes to respiration rates and heat-shock protein production, and temperature can also alter symbiont function. At the ecological level, temperature influences sponge reproduction, feeding and growth and therefore has the potential to influence population dynamics and wider ecosystem function. Responses of sponges were variable when comparing the impacts of short-term temperature increases between different geographic regions, with reports of both tolerance and population declines. However, within tropical systems, there are increasing reports of higher tolerance of sponges to increases in temperature compared to corals and of sponges showing subsequent increases in abundance where coral populations have declined. However, there are still very few studies that have focused on understanding the mechanisms of acclimation to temperature stress, which should be a focus of future research.