Abstract
Coral reefs are biodiversity hotspots that provide income and resources to millions of people worldwide. Yet, they are highly vulnerable to the “deadly trio” of climate change stressors – ocean warming, acidification and hypoxia (low O2). If current emission trends continue, the future of coral reefs is at risk. However, scientists, including myself, have recently discovered naturally stress-resistant coral populations that appear to thrive under variable, extreme environmental conditions that frequently expose corals to heat, acidification and low O2. Strong environmental variability therefore has significant potential to increase coral stress tolerance. If true, this could fundamentally change the outlook for future reef persistence. Yet, it remains poorly understood when environmental variability is beneficial (or not) and whether variability-enhanced stress resilience could aid future coral reef survival. The aim of this project is therefore to determine how environmental variability modulates coral multi-stress tolerance and persistence in a future ocean. By combining fieldwork in reefs with strong gradients in environmental variability with controlled mesocosm experiments, I will address four research questions: 1. How does exposure history modulate coral resistance to heat, acidification and hypoxia? 2. How do stressor amplitude, frequency and duration influence resistance to single-stressor variability (temperature, pH, O2)? 3. How do interactions between multiple co-varying stressors (temperature, pH, O2) alter stress tolerance? 4. Can reefs with strong environmental variability serve as resilience hotspots and promote future reef persistence? Using mathematical tools from the field of ecotoxicology, I will develop a novel mechanistic framework to predict how time-dependent exposure to co-varying environmental stressors alters coral multi-stress tolerance and persistence under rapid climate change. This innovative approach will provide a step change in our understanding of how reef-scale environmental processes alter coral adaptive capacity and future survival, leading to better predictions of where resilience hotspots occur and providing critical knowledge for reef conservation.
Netherlands