Multispecies Competition Among Corals, Sponges, and Algae on Reefs in the U.S. Virgin Islands
University of the Virgin Islands, 2015-2017 Committee: Marilyn Brandt, Andia Chaves Fonnegra, Ian Enochs Survival of reef-building Caribbean corals will depend on whether corals can compete with sponges and algae, but we know very little about how these three groups compete together, in a multispecies context. My masters research comprised a field experiment monitored with 3D photogrammetry, and a simulation model based on the outcomes of that experiment, to evaluate multispecies (coral-sponge-algae) competitive outcomes and simulate their influence on benthic communities. (link to full thesis: here). |
Field Experiment:
We arranged sponges and algae around coral to recreate competitive interactions between two or three groups and compare the outcome of each competitive scenario. We found that one sponge overgrew coral more rapidly during multispecies competition, when the sponge was also in contact with algae. Direct contact with algae appeared to confer a competitive advantage to the sponge, for example through providing nutrition or structural support. This "algae-sponge facilitation" is a novel interaction with concerning implications for reef-building corals, especially those on the many Caribbean reefs where sponges and algae now outnumber reef-building corals. (Olinger et al., 2021). |
last updated March 2019