Coral reefs as ocean-connected ecosystems: Impacts on food webs and reef futures under climate change.

Abstract

Coral reef ecosystems are inherently dependent on their surrounding ocean. Mounting evidence reveals that oceanographic processes deliver pelagic subsidies that shape coral reef food webs and influence reef persistence following disturbance. These findings are challenging the classical view of reefs as 'self-sustaining' ecosystems in oligotrophic seas. Yet our observations of these biophysical interactions are limited, and we lack a fundamental understanding of how ocean-reef interactions structure shallow reef dynamics. As climate change continues to alter fundamental physical processes within our ocean, the impacts of ocean-reef interactions on reef futures remain unknown. In this review, we offer a forward-looking perspective to catalyze our understanding of ocean-reef connections through interdisciplinary studies and more standardized approaches to data collection and validation. We provide a primer for ecologists on some of the foundational physical processes structuring subsurface temperature dynamics and resource supply to coral reef ecosystems and synthesize the available evidence on how these biophysical interactions influence reef food webs, from microbes to sharks and ultimately humans. Lastly, we emphasize how climate change is restructuring vital biophysical processes in the ocean and on reefs and identify practical solutions for improving our ability to more critically evaluate ocean-reef interactions across scales. Achieving this will be crucial to improve our projections of coral reef futures and to help inform strategic management to support and promote reef persistence under climate change.