Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up.
Caribbean coral reefs have been transformed in the past few decades with the demise of reef-building corals, and sponges are now the dominant habitat-forming organisms on most reefs. Competing hypotheses propose that sponge communities are controlled primarily by predatory fishes (top-down) or by th...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2013-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3648561?pdf=render |
| _version_ | 1817980545492058112 |
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| author | Joseph R Pawlik Tse-Lynn Loh Steven E McMurray Christopher M Finelli |
| author_facet | Joseph R Pawlik Tse-Lynn Loh Steven E McMurray Christopher M Finelli |
| author_sort | Joseph R Pawlik |
| collection | DOAJ |
| description | Caribbean coral reefs have been transformed in the past few decades with the demise of reef-building corals, and sponges are now the dominant habitat-forming organisms on most reefs. Competing hypotheses propose that sponge communities are controlled primarily by predatory fishes (top-down) or by the availability of picoplankton to suspension-feeding sponges (bottom-up). We tested these hypotheses on Conch Reef, off Key Largo, Florida, by placing sponges inside and outside predator-excluding cages at sites with less and more planktonic food availability (15 m vs. 30 m depth). There was no evidence of a bottom-up effect on the growth of any of 5 sponge species, and 2 of 5 species grew more when caged at the shallow site with lower food abundance. There was, however, a strong effect of predation by fishes on sponge species that lacked chemical defenses. Sponges with chemical defenses grew slower than undefended species, demonstrating a resource trade-off between growth and the production of secondary metabolites. Surveys of the benthic community on Conch Reef similarly did not support a bottom-up effect, with higher sponge cover at the shallower depth. We conclude that the structure of sponge communities on Caribbean coral reefs is primarily top-down, and predict that removal of sponge predators by overfishing will shift communities toward faster-growing, undefended species that better compete for space with threatened reef-building corals. |
| first_indexed | 2024-04-13T22:54:56Z |
| format | Article |
| id | doaj.art-5d92370949c244498ad0c6e130857cd2 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-13T22:54:56Z |
| publishDate | 2013-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-5d92370949c244498ad0c6e130857cd22022-12-22T02:26:04ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0185e6257310.1371/journal.pone.0062573Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up.Joseph R PawlikTse-Lynn LohSteven E McMurrayChristopher M FinelliCaribbean coral reefs have been transformed in the past few decades with the demise of reef-building corals, and sponges are now the dominant habitat-forming organisms on most reefs. Competing hypotheses propose that sponge communities are controlled primarily by predatory fishes (top-down) or by the availability of picoplankton to suspension-feeding sponges (bottom-up). We tested these hypotheses on Conch Reef, off Key Largo, Florida, by placing sponges inside and outside predator-excluding cages at sites with less and more planktonic food availability (15 m vs. 30 m depth). There was no evidence of a bottom-up effect on the growth of any of 5 sponge species, and 2 of 5 species grew more when caged at the shallow site with lower food abundance. There was, however, a strong effect of predation by fishes on sponge species that lacked chemical defenses. Sponges with chemical defenses grew slower than undefended species, demonstrating a resource trade-off between growth and the production of secondary metabolites. Surveys of the benthic community on Conch Reef similarly did not support a bottom-up effect, with higher sponge cover at the shallower depth. We conclude that the structure of sponge communities on Caribbean coral reefs is primarily top-down, and predict that removal of sponge predators by overfishing will shift communities toward faster-growing, undefended species that better compete for space with threatened reef-building corals.http://europepmc.org/articles/PMC3648561?pdf=render |
| spellingShingle | Joseph R Pawlik Tse-Lynn Loh Steven E McMurray Christopher M Finelli Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up. PLoS ONE |
| title | Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up. |
| title_full | Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up. |
| title_fullStr | Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up. |
| title_full_unstemmed | Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up. |
| title_short | Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up. |
| title_sort | sponge communities on caribbean coral reefs are structured by factors that are top down not bottom up |
| url | http://europepmc.org/articles/PMC3648561?pdf=render |
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