Levels of intervention – reducing SCUBA-diver impact within subtropical marine protected areas

Subtropical rocky reefs are ecotonal habitats that support unique biodiversity and attract all levels of self-contained underwater breathing apparatus (SCUBA) divers. Compared to tropical coral reefs, there have been few studies evaluating the effects of SCUBA diving on these communities. Cape Byron and Solitary Islands marine parks in northern New South Wales include some of the most intensively dived sites in Australia, outside of the Great Barrier Reef. Most of those diving sites are located within management zones that offer the highest level of protection. Contact by divers, or their equipment, is a principal mechanism for chronic impact on benthic life forms. This study tested two levels of intervention over the standard dive briefing to determine their effectiveness for reducing SCUBA-diver contact: (1) targeted pre-dive briefing with specific reference to minimising benthic contact; and (2) direct underwater reinforcement at the time of first contact. Both intervention levels significantly reduced the number of contacts made by divers. The targeted briefing is the easiest and most cost effective to implement and is the least intrusive on the diving experience. The more intensive approach of underwater intervention may be required in more sensitive areas, or for those divers who have been shown to create the majority of damage.