The influence of boat moorings on anchoring and potential anchor damage to coral reefs

摘要

Recreational boating is increasingly popular and provides social and economic benefits, but can also have ecological impacts, including damage from anchoring on sensitive seabed habitats like coral reefs. Mooring buoys are commonly used to manage anchoring activity, and I tested whether they moderated anchoring on coral reefs in the British Virgin Islands. A spatial survey revealed that overall boat use (moored plus anchored) was 3.6 times higher at sites with moorings than those without. The density of boats anchored on coral reef was, however, reduced by roughly half at sites with moorings. A survey of two sites before and after moorings were installed confirmed that the addition of moorings increased the total number of boats at a site, but reduced the rate of anchoring on reef. At any given site, the rate of anchoring on reef increased as the total number of boats present increased, but the effect of crowding was diminished at sites with moorings. Moorings can thus be an effective management tool for mitigating anchor damage to sensitive habitats, and because boat densities continue to rise worldwide, these findings focus attention on discovering why moorings reduce the tendency of boats to anchor on reef as sites become more crowded.