Trade-offs between short- and longer-term resilience to warming within and between subtidal marine assemblages

Abstract

Abstract Subtidal marine ectotherm physiological responses vary with ocean warming. Predicting these responses is important for ecosystem assessments to inform management and conservation strategies. Falkland Islands coastal species representing different mobility, feeding guilds, and habitats were tested, through laboratory incubation experiments, to estimate their short- (acute - seconds to hours) and longer-term (acclimation - weeks to months) resilience to ocean warming, to understand if ecological traits affect temporal trade-offs in responses, and contrasted with other marine assemblages. We found trait-specific, and species-specific, trade-offs in resilience to short-term and longer-term warming. Filter feeders and predators had higher acute tolerance than detritivores and herbivores. Lower acclimation capacity was found in molluscs, sessile species, filter feeders and kelp associated species. Benthic species had amongst the highest acclimation capacity. When compared to analogous experiments conducted with the same methodology at 10 different locations, across latitudes, we found a consistent relationship between short- and long- term resilience across marine assemblages, but with notable exceptions from unpredictable environments with episodic warming events; the Peruvian upwelling and Falklands fauna had a lower short-term resilience, relative to their longer-term resilience, than the other assemblages. When predicted rates of ocean warming under a high anthropogenic carbon emission scenario and anticipated increases in marine heat waves were taken into account, low latitude assemblages showed greater vulnerability in terms of years until acute thermal safety margins are breached (less than 500 years) than higher latitude assemblages (up to 4000 years), which is largely driven by projected rates of ocean warming. Understanding this variation, and the relationship to predictability, in coastal communities will be informative for predicting ecosystem responses and informing management and conservation strategies.