1. A coral-algal phase shift in Mesoamerica not driven by changes in herbivorous fish abundance
- Author
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Yves-Marie Bozec, Robert M. Seymour, Craig R. Johnson, Gilberto Acosta-González, Jesús Ernesto Arias-González, Joaquín Rodrigo Garza-Pérez, and Tak Fung
- Subjects
0106 biological sciences ,Coral ,Population Dynamics ,Marine and Aquatic Sciences ,lcsh:Medicine ,Plant Science ,01 natural sciences ,Materials Physics ,Microalgae ,Biomass ,Aquaculture of coral ,lcsh:Science ,Multidisciplinary ,geography.geographical_feature_category ,biology ,Ecology ,Animal Behavior ,Coral Reefs ,Physics ,Fishes ,Coral reef ,Plants ,Anthozoa ,Pollution ,Trophic Interactions ,Grazing ,Community Ecology ,Corals ,Physical Sciences ,Engineering and Technology ,Coral reef protection ,Sedimentation ,Research Article ,Environmental Engineering ,Algae ,Death Rates ,Materials Science ,Marine Biology ,010603 evolutionary biology ,Plant-Animal Interactions ,Animals ,Herbivory ,Reef ,Mexico ,Ecosystem ,Demography ,geography ,Behavior ,Resilience of coral reefs ,010604 marine biology & hydrobiology ,Plant Ecology ,Ecology and Environmental Sciences ,Water Pollution ,lcsh:R ,Organisms ,Biology and Life Sciences ,biology.organism_classification ,Fishery ,People and Places ,Earth Sciences ,Reefs ,Environmental science ,lcsh:Q ,Environmental issues with coral reefs ,Zoology - Abstract
Coral-algal phase shifts in which coral cover declines to low levels and is replaced by algae have often been documented on coral reefs worldwide. This has motivated coral reef management responses that include restriction and regulation of fishing, e.g. herbivorous fish species. However, there is evidence that eutrophication and sedimentation can be at least as important as a reduction in herbivory in causing phase shifts. These threats arise from coastal development leading to increased nutrient and sediment loads, which stimulate algal growth and negatively impact corals respectively. Here, we first present results of a dynamic process-based model demonstrating that in addition to overharvesting of herbivorous fish, bottom-up processes have the potential to precipitate coral-algal phase shifts on Mesoamerican reefs. We then provide an empirical example that exemplifies this on coral reefs off Mahahual in Mexico, where a shift from coral to algal dominance occurred over 14 years, during which there was little change in herbivore biomass but considerable development of tourist infrastructure. Our results indicate that coastal development can compromise the resilience of coral reefs and that watershed and coastal zone management together with the maintenance of functional levels of fish herbivory are critical for the persistence of coral reefs in Mesoamerica.
- Published
- 2017