Indirect effects of overfishing on Caribbean reefs: Sponges overgrow reef-building corals
- Published
- Accepted
- Subject Areas
- Aquaculture, Fisheries and Fish Science, Conservation Biology, Ecology, Environmental Sciences, Marine Biology
- Keywords
- food webs, trophic cascades, indirect effects, resource trade-offs, chemical defense, top-down control, spatial competition, coral reefs, MPAs, marine protected areas
- Copyright
- © 2015 Loh et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. Indirect effects of overfishing on Caribbean reefs: Sponges overgrow reef-building corals. PeerJ PrePrints 3:e836v1 https://doi.org/10.7287/peerj.preprints.836v1
Abstract
Consumer-mediated indirect effects at the community-level are difficult to demonstrate empirically. Here, we show an explicit indirect effect of overfishing on competition between sponges and reef-building corals from surveys of 69 sites across the Caribbean. Removal of sponge-eating angelfishes and parrotfishes resulted in > 3 fold increase in overgrowth of corals by sponges, with coral-sponge contact increasing from 11.0% to 25.6%, and these sponges were mostly species palatable to sponge predators. Palatable species have faster rates of growth or reproduction than defended sponges, which instead make metabolically expensive chemical defenses. On average, overfished sites had lower macroalgal cover, contrary to prevailing assumptions about seaweed control by herbivorous fishes. Coral-sponge competition provides an additional and unambiguous justification for marine protected areas (MPAs) in the Caribbean, where the conceptual model of sponge community ecology and defense trade-offs is notable for the clarity of top-down control and indirect effects across a broad geographic region.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
nMDS plot of survey sites by benthic community structure using square-root transformed occurrences of benthic categories
Sites labeled green are less-fished, and sites labeled blue are overfished. The following benthic categories were used: rock, fire coral, rubble, zoanthid, sponges, other benthos, hard coral, gorgonian, silt, sand, turf, macroalgae, and coralline algae. Prefixes of site names denote the following locations: B, Bahamas; C, Cayman Islands; D, Dominican Republic; E, St. Eustatius; F, Key Largo, FL; J, Jamaica; M, Martinique; O, Bonaire; P, Bocas del Toro, Panama; R, Puerto Rico; S, St. Lucia; U, Curaçao; X, Mexico.
