Multiple Stressors

On virtually all coral reefs global climate change is superimposed on a suite of local anthropogenic stressors.

Does management of local coastal ecosystems matter in the face of climate change?Although intuitively it makes sense that ecosystems protected from local stressors would be healthier and more resilient to climate change, the scientific evidence is mixed. Our work, probing ecosystems across gradients of disturbance intensity, is helping to resolve this mystery, revealing how local management can help.

 
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Multiple stressors and coral reefs

We believe that understanding how global climate change is impacting ecosystems means acknowledging the underlying local anthropogenic stressors to which they are also subjected. On coral reefs, this includes everything from coastal development to overfishing. Our research on Kiritimati takes place across the atoll’s spatial gradient of local anthropogenic impacts, from coral reef sites near villages, the port and other infrastructure to very minimally disturbed ones at the remote end of the atoll.

We have used both size and species-based approaches to understand how coral reef community structure changes with increased anthropogenic stressors (Dunic et al. 2017 J. Animal Ecology, Robinson & Baum 2016 Can. J. Fish. Aquat Sci., Wood et al. 2015 Ecology). And all of our work on the impacts and recovery from the 2015-2016 El Niño event on the reef - including that of the entire reef and coral community (Baum et al. 2023 Science Advances), focusing on just soft coral (Maurcieri & Baum 2021 Biological Conservation), the habitat complexity (Magel et al. 2019 Scientific Reports), reef fish communities (Magel et al. 2020 Ecological Applications), coral resilience (Claar et al. 2020 Nature Communications) and their microbes (McDevitt-Irwin et al. 2019 Coral Reefs) - also examines how heat stress interacts with local stressors. Thus far, we’ve found compelling evidence that corals reefs not exposed to local stressors tend to have greater resilience to heat stress.

Photo Credits: Banner (Danielle Claar), Reef on Kiritimati (Danielle Claar), Garbage on beach (Kristina Tietjen)