Epifaunal community structure in Acropora spp. (Scleractinia) on the Great Barrier Reef: implications of coral morphology and habitat complexity

The structure and composition of the infauna of the coral P. damicornis in the Capricorn Group, Great Barrier Reef, is examined. A total of 40 coral heads were sampled from four localities on two reefs and 951 individuals of 101 species were extracted. This is five times the species collected from P. damicornis in previous studies. A comprehensive species list is provided. Infauna was dominated by only a few species, 20 species accounting for 78% of individuals and 36 species recorded only as single individuals. Crustacea was the dominant taxon present, comprising 72% of species and 86% of individuals. Number of species and number of individuals show significant regressions with size of coral heads. Differences in physical environment at the four sites did not affect species diversity within coral heads. However, several common species only occurred within particular habitats. Species diversity is discussed briefly in relation to the behaviour of resident symbionts, random pelagic settlements of larvae, the size of target corals and habitat heterogeneity in coral heads.

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The effects of marine reserve protection on the trophic relationships of reef fishes on the Great Barrier Reef

Environmental Conservation ◽

10.1017/s0376892903000195 ◽

2003 ◽

Vol 30 (2) ◽

pp. 200-208 ◽

Cited By ~ 133

Author(s):

N.A.J. Graham ◽

R.D. Evans ◽

G.R. Russ

Keyword(s):

Coral Reef ◽

Great Barrier Reef ◽

Reef Fish ◽

Coral Reef Fish ◽

Habitat Complexity ◽

Prey Species ◽

Marine Reserve ◽

Trophic Relationships ◽

Barrier Reef ◽

Prey Fish

What are the effects of no-take marine reserves on trophic relationships of coral reef fish? Previous studies often have lacked detailed dietary information on major predators, and have often been confounded by differences in habitat complexity between reserve and fished sites. This study investigates the effects of marine reserve protection on predator-prey interactions of coral reef fish on the inshore islands of the Great Barrier Reef (GBR). The abundance of species of prey fish of Plectropomus leopardus (Serranidae), a piscivore and the major target of the hook and line fisheries on the GBR, were estimated in protected and fished zones. These prey species were identified from previous detailed studies of the diet of P. leopardus. Fish populations and habitat characteristics were surveyed by underwater visual census. Previous studies had determined that the biomass of P. leopardus was 3–4 times higher in protected than fished zones in the Whitsunday and Palm Islands, central GBR, after 14 years of protection. Eight of the nine prey species had a higher density within fished zones than protected zones, six significantly so. The density of all prey fish was twice that in the fished than the protected zone (p < 0.001). There were no significant differences in availability of different sized refuge holes, structural complexity or live coral cover between zones. Thus, important attributes of habitat complexity did not confound the comparisons between reserve and fished zones. Finally, a significant negative correlation (r = 0.46) between coral trout biomass and summed prey fish biomass suggested that predation may be an important structuring process in this system. The results have implications for the conservation of fishery targets and their prey. The study highlights the potential ecosystem implications of the use of no-take marine reserves as conservation and fisheries management tools.

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