Temporal change in hard substrate communities 10-250m, the Bahamas
9th Int Coral Reef Symp., Bali, Indonesia
Fine-scale change in hard-substrate community structure was determined through repeat photography of'natural substrates and artificial settling panels over a three year period and along a depth gradient of 10-250 m off Lee Stocking Island, the Bahamas. Indices were developed to address temporal changes in substrate components, including percent areas occupied and addition or loss of individuals or colonies. Overall values for change were relatively low at 10 m depth, increased to a maximum between 30 and 50 m, and then declined with increasing depth to 250 m. Numbers of fish grazing scars counted on artificial settling panels were positively correlated with the loss index and negatively correlated with algal cover, suggesting that fish are a major contributor to the observed temporal changes in the sessile community between 10-50 m. Dominant substrate components shifted from algae to corals to sponges with increasing depth. Although correlations between change indices and hard-substrate community structure suggest an association between intermediate values of change and high species diversity, a simple causal relationship between agents (wave action, fish grazing) of fine-scale change and community structure was not demonstrated. Instead, a complex interplay of abiotic and biotic disturbance forces, diminishing light levels, and changing phyletic dominance accompanied by shifting tradeoffs in competitive abilities occurs along the bathymetric gradient.
Liddell, W. D. and W.E. Avery. 2000. Temporal change in hard substrate communities 10-250m, the Bahamas. Proc. 9th Int Coral Reef Symp., Bali, Indonesia 2:1053-1058.