Bioerosion of Porites coral by Lithophaga bivalve in the eastern tropical Pacific: Interactive effects in an island reef

Coral reefs are maintained by a balance between formation (calcifiers) and destructive processes (dissolution and erosion). In eastern tropical Pacific reefs, Porites genus is the second-largest contributor to CaCO3 production, but is affected by bioerosion. In this study, we evaluate the interaction between Lithophaga and Porites in an island reef in the Mexican Pacific by quantifying bioerosion rate, its impact on CaCO3 production, and contrasting growth models. To achieve this, Porites lobata colonies were collected to evaluate calcification and CaCO3 production. Shells of Lithophaga ( Leiosolenus plumula) were extracted from corals, and age and length fed into a growth model. Our results indicate a high bioerosion rate (21.9 +/- 4.1 %), representing 8.3 % of overall CaCO3 production. Bivalves' age (8 y) was less than corals (12.6 y), and cohort analysis indicates an intense recruitment. We associate this with high productivity derived from the island's oceanography, promoting nutrient enrichment, a plausible scenario for reefs under eutrophication conditions