Publication Abstract

Comment on "Rivers, runoff, and reefs"

This comment is not intended as a direct criticism of the conclusions of the recent paper bRivers, runoff, and reefsQ by McLaughlin et al. (2003), but rather seeks to (1) highlight the potential problems and limitations that exist with global scale studies such as this, and (2) comment on the bias of recent and current research that often focuses exclusively on clear-water reef environments. Many reef environments that may be perceived as being marginal in terms of their environmental parameters (sensu Kleypas et al., 1999), including sites subject to high terrigenous sediment input, have received limited attention compared to the vast biological, ecological and geological literature that relates to clear-water reef environments (see Perry and Larcombe, 2003, for a discussion). These more marginal environments are often regarded as impoverished in terms of coral abundance and diversity, and characterised by reduced coral growth rates and framework-building capacity. Whilst this in itself is not always the case, it more importantly ignores the fact that these more restricted coral communities should not automatically be regarded as impacted or disturbed communities, but rather as alternative states of reef development. Whilst McLaughlin et al. (2003) deal with an important issue, namely the perceived links that exist between increasing sediment input and reduced reef development, we believe their results may be skewed due to (1) incorporation of the dReefBaseT data set as a resource for defining reef presence/absence, and (2) more widespread misconceptions about the nature of turbid-zone reefs or coral communities, i.e., that occur under conditions of high sediment input and/ or turbidity.

Reference:

I.A. Macdonald, C.T. Perry and P. Larcombe (2005). Comment on "Rivers, runoff, and reefs" . Global and Planetary Change, 45: 333-337.