Simultaneous top-down and bottom-up forces control macroalgal blooms on coral reefs (Reply to the comment by Hughes et al.)

Hughes et al. (1999) implied that I discounted the role of herbivory as a factor controlling macroalgal abundance on coral reefs. However, I explicitly recognized the contemporaneous effects of both grazing and nutrient availability as potential controllers of macroalgal blooms on coral reefs (see Fig. 1, RDM, and references in Lapointe 1997). While the term "macroalgal bloom" has been used loosely and is not defined in prior studies, I define this term to indicate an increase in abundance, above normal background levels, of a species in a geographic area or particular coral reef habitat.