Predator release of the gastropod Cyphoma gibbosum increases predation on gorgonian corals

Abstract

When large, predatory fishes and invertebrates were excluded from areas of a coral reef in the Florida Keys, USA, densities of the normally rare gastropod Cyphoma gibbosum, a principal predator of gorgonian corals, increased 19-fold. Gorgonians in predator exclosures were grazed more frequently and extensively by C. gibbosum than were gorgonians in uncaged areas. In exclosures, 14% of all gorgonians showed recent predation by C. gibbosum, with 62% of the entire colony surface being removed from these attacked individuals. In areas where predators of C. gibbosum were not excluded, only 5% of gorgonians exhibited recent damage, with only 26% of the colony surface being removed from these few damaged individuals. Thus, the increases in both frequency and extent of attack combined to produce an 8x increase in gorgonian damage following removal of large predators. These patterns suggest that predators typically suppress C. gibbosum populations, that overfishing of these predators could release C. gibbosum from top-down control, and that this release will allow increased damage to gorgonian corals.

Herbivory effects on benthic algal composition and growth on a coral reef flat in the Egyptian Red Sea

“…Nearby locations (distance to cages <1 m) without any cage treatment served as controls. Further cage controls were not used, since previous studies have shown that a mesh size of 2.5 cm has little impact on algal community development, sedimentation rates, or water movement (Miller et al 1999, Smith et al 2001, Burkepile & Hay 2007. At each of the 8 sites, all 3 treatments were present, randomly distributed, and located within 1 m from each other.…”

Nutrient versus herbivore control of macroalgal community development and coral growth on a Caribbean reef

“…Mesh of this size has little impact on algal community development, coral growth, sedimentation rates, or bulk water flow , Smith et al 2001, Burkepile & Hay 2007. Adjacent uncaged areas of 4 m 2 (n = 8) served as controls.…”

Isotopic labeling and antifungal resistance as tracers of gut passage of the sea fan pathogen Aspergillus sydowii

“…Recent work suggests that the removal of top predators due to over-fishing may allow the release of C. gibbosum, leading to a large increase in octocoral damage due to grazing (Burkepile & Hay 2007). This suggests that sites with reduced top predator densities may be particularly susceptible to vectored disease transmission.…”