Growth Characteristics of Reef-Building Corals Within and External to a Naval Ordinance Range: Vieques, Puerto Rico

The skeletal growth of reef·building corals is known to be sensitive to the environment. In particular, high levels of sedimentation and turbidity lead to decreased growth rate, suppressed growth variation, and, ultimately, coral death because of reduced illumination necessary to zooxanthellae and/or increased energy expenditure by the coral animal to remove impacted sediments.To assess the effect of Naval Ordnance Range usage at Vieques, Puerto Rico, specimens of Montastrea annulariswere collected from reefs adjacent to and removed from the range area. Growth was measured from annual increments revealed by X-radiography of medial slabs of the coral skeletons. Mean growth rates and growth variances were calculated for each station or station grouping over the common time period 1970-1977.Statistical comparison of the growth data reveals a general similarity between range and control stations. This evidence coupled with quantitative coral abundance and diversity data of others indicate a lack of anomalous and adverse sedimentation/turbidity conditions affecting corals on reefs near the range area.Chronologies of coral band widths compared to historical recorded environmental data indicate that a major natural parameter which controls coral growth in Vieques is annual water temperature variation.