The emergent role of small-bodied herbivores in pre-empting phase shifts on degraded coral reefs.

ABSTRACT: Natural and anthropogenic stressors can cause phase shifts from coral-dominated to algal-dominated states. In the Caribbean, over-fishing of large herbivorous fish and disease among the long-spined urchin, Diadema, have facilitated algal growth on degraded reefs. We found that diminutive species of urchin and parrotfish, which escaped die-offs and fishing pressure, can achieve abundances comparable to total herbivore biomass on healthier, protected reefs, and exert sufficient grazing function to pre-empt macroalgal dominance following mass coral mortality. Grazing was highest on the most degraded reefs, and was driven by small herbivores that made up >93% of the average herbivore biomass (per m²). We suggest that previously marginal species can achieve a degree of functional red

SUBMITTER: Kuempel CD 

PROVIDER: S-EPMC5215077 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature