Ocean warming is driving large-scale changes to coastal ecosystems worldwide. Nevertheless, the distribution and magnitude of climate impacts is spatially variable. Not all locations are affected equally by warming and within any given biological community, species may respond differently to ongoing changes to the local climate regime. As such, it remains a pressing scientific objective to understand and predict how the ecological impacts and opportunities presented by warming will manifest both between and within local biological communities. Until now, global projections of the biological impacts of climate change have primarily considered that thermal niches remain constant across a species range, overlooking important variation in adaptive capacity among populations, with major implications for predicting warming vulnerability. Vulnerability of an organism to warming is a function of exposure (i.e. rate of warming) and inherent sensitivity to increasing temperatures. Sensitivity to warming in turn, is characterized by the proximity between an organism’s upper thermal limits and the maximum local environmental temperatures that it experiences. As such, warming sensitivity and vulnerability are dynamic between species, space and time, as they integrate intrinsic differences in the thermal niche between species and extrinsic differences in climatology between locations.
Quantifying the variability in local and regional warming vulnerability has important applications for the stewardship of coastal ecosystems. Local to regional scales are those at which governance typically occurs and are arguably the spatial scales of most interest to local users and stakeholders. This research facilitates ecosystem-based management by identifying potentially resistant locations (e.g. climate refugia) and populations (e.g. those pre-selected for warming tolerance), and vulnerable situations where reducing other pressures on biodiversity should be prioritized.
The overarching questions addressed by this project were 1) How do patterns in thermal tolerance breadth and thermal safety margins vary throughout species’ geographical ranges? And 2) What are the environmental drivers, biotic traits and evolutionary factors that determine an organisms thermal tolerance? Through identifying the nature of thermal tolerance patterns and identifying some of the mechanisms influencing these patterns, this research aims to increase the accuracy and resolution of predictions of the sensitivity of marine biota to climate change.
