Macroborer Presence on Corals Increases with Nutrient Input and Promotes Parrotfish Bioerosion

Authors

Mallory M. Rice, University of California - Santa Barbara
Rebecca L. Maher, Oregon State University
Adrienne M.S. Correa, Rice University
Holly V. Moeller, University of California - Santa Barbara
Nathan P. LeMoine, Marquette UniversityFollow
Andrew A. Shantz, Pennsylvania State University
Deron E. Burkepile, University of California - Santa Barbara
Nyssa J. Silbiger, California State Univeristy

Document Type

Article

Publication Date

4-2020

Publisher

Springer

Source Publication

Coral Reefs

Source ISSN

0722-4028

Abstract

Bioerosion by reef-dwelling organisms influences net carbonate budgets on reefs worldwide. External bioeroders, such as parrotfish and sea urchins, and internal bioeroders, including sponges and lithophagid bivalves, are major contributors to bioerosion on reefs. Despite their importance, few studies have examined how environmental (e.g., nutrients) or biological drivers (e.g., the actions of other bioeroders) may influence bioeroder dynamics on reefs. For example, internal bioeroders could promote external bioerosion by weakening the coral skeletal matrix. Our study investigated: ( 1) whether nutrient supply influences the dynamics between internal and external bioeroders and ( 2) how the presence of a boring bivalve, Lithophaga spp., influences parrotfish bioerosion on massive Porites corals. We hypothesized that nutrient supply would be positively correlated with Lithophaga densities on massive Porites colonies, and that as bivalve density increased, the frequency and intensity of parrotfish bioerosion would increase. To test these hypotheses, we analyzed six time points over a 10-yr period from a time series of benthic images and nitrogen content of a dominant macroalga from the fringing reefs around Moorea, French Polynesia. We found Lithophaga densities were positively correlated with nitrogen availability. Further, massive Porites that are more infested with Lithophaga had both a higher probability of being bitten by parrotfish and a higher density of bite scars from parrotfishes. Our findings indicate that increasing nutrient availability may strengthen the relationship between internal and external bioeroders, suggesting that colonies at more eutrophic sites may experience higher bioerosion rates.

Comments

Accepted version. Coral Reefs, Vol. 39, No. 2 (April 2020): 409-418. DOI. © 2020 Springer. Used with permission.

Recommended Citation

Rice, Mallory M.; Maher, Rebecca L.; Correa, Adrienne M.S.; Moeller, Holly V.; LeMoine, Nathan P.; Shantz, Andrew A.; Burkepile, Deron E.; and Silbiger, Nyssa J., "Macroborer Presence on Corals Increases with Nutrient Input and Promotes Parrotfish Bioerosion" (2020). Biological Sciences Faculty Research and Publications. 814.
https://epublications.marquette.edu/bio_fac/814