The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts
Climate-driven changes in biotic interactions can profoundly alter ecological communities, particularly when they impact foundation species. In marine systems, changes in herbivory and the consequent loss of dominant habitat forming species can result in dramatic community phase shifts, such as from coral to macroalgal dominance when tropical fish herbivory decreases, and from algal forests to ‘barrens’ when temperate urchin grazing increases. Here, we propose a novel phase-shift away from macroalgal dominance caused by tropical herbivores extending their range into temperate regions. We argue that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas. Overgrazing of temperate macroalgae by tropical herbivorous fishes has already occurred in Japan and the Mediterranean. Emerging evidence suggests similar phenomena are occurring in other temperate regions, with increasing occurrence of tropical fishes on temperate reefs.
- Received April 13, 2014.
- Accepted June 13, 2014.
- © 2014 The Author(s) Published by the Royal Society. All rights reserved.
- 1. Introduction
- 2. Poleward boundary currents, other ocean warming hotspots and their consequences to species distribution and abundance
- 3. Intrusion of tropical herbivorous fishes into temperate systems and impacts on temperate algal and seagrass beds
- 4. Mechanisms facilitating the tropicalization of temperate systems by herbivorous fishes
- 5. How will other effects of climate change modulate the interaction between temperate macroalgae and range-shifting tropical herbivores?
- 6. Socio-ecological consequences of climate-mediated changes in herbivory
- 7. Conclusion
- Funding statement
- Figures & Data
- Info & Metrics