Cleaner water may make corals more resistant to bleaching, according to research by Daniel Wagner, Philip Kramer and Robert van Woesik in a study published in a recent issue of the journal Marine Ecology Progress Series.
The authors looked at coral bleaching in the Florida Keys from 2005 and 2007, with the primary objectives of the study being to examine the spatial pattern of coral bleaching and its relationship to coral community composition and habitat and to determine the relationship between environmental parameters and coral-bleaching prevalence.
Combining survey data (from more than 400 sites) with water quality parameters (measured at about 150 sites), the authors statistically analysed their results and found that there was a clear relationship between bleaching and high water temperature, high concentrations of dissolved inorganic nitrogen, and high chlorophyll a concentrations in the water column .
Based on their results, the authors suggest that locally regulating waste water discharge from the land to minimise nutrients and reduce local water-column productivity may reduce coral bleaching when regional water temperatures are high.
For more information, see the paper: Wagner, DE, P Kramer and R van Woesik (2010) Species composition, habitat, and water quality influence coral bleaching in southern Florida. Marine Ecology Progress Series 408, pp. 65–78.