Increased Spatial and Temporal Variability in Coral Damage Caused by Recreational Scuba Diving

Abstract

The most dramatic changes in natural environments caused by human recreation are often during the initial use of a site, when the most susceptible and fragile species are disturbed. Approaches to managing the effects of recreational activities often assume that site impacts accumulate under sustained patterns of use and that the rate of accumulation is predictably related to the amount of initial use that individual sites receive. We investigated the patterns of impact caused by the experimental opening of two new scuba diving sites in the Great Barrier Reef Marine Park, Queensland, Australia. Changes in the abundance and condition of corals at the dive sites and two undived (control) sites were monitored for 5 mo before the sites were opened and for a further 13 mo after regular dive visits began. Sampling was stratified at increasing distances (0, 40, and 80 m) away from the point of entry to each site to determine spatial patterns of impact. Despite regular use of the sites by dive charters, impacts occurred as repeated discrete pulses in coral damage that were spatially and temporally heterogeneous. Increases in the density of broken branching corals were typically short‐term and occurred asynchronously within a single stratum or dive site. Our results show that repeated use of coral reef dive sites does not necessarily lead to cumulative deterioration in their condition. The heterogeneous patterns of impact that we detected appear to be associated with variability in diver behavior and to the relatively rapid growth of broken coral branches. To limit damage in these popular environments, management actions that identify and mitigate the causes of damaging behavior are likely to be more pragmatic and efficient than setting numerical limits to site use.

Forecasting the combined effects of disparate disturbances on the persistence of long-lived gorgonians: a case study of Paramuricea clavata

“…Long-lived sessile species such as red gorgonian are especially vulnerable to disturbances due to slow population dynamics (Hughes & Jackson 1985, Dayton et al 1995, Garrabou & Harmelin 2002, Coma et al 2004). The past, and expected future, increases in multiple anthropogenic mortality sources create the need for a joint assessment of the threats they pose to marine long-lived species, especially in MPAs (Rouphael & Inglis 2002, Barker & Roberts 2004. One approach to such an assessment is to conduct long-term monitoring to examine the response capacity of the species facing increasing disturbances.…”

Effectiveness of lionfish removal efforts in the southern Caribbean

“…Fishing of lionfish commonly occurs on easily accessible and popular dive sites and house reefs of dive operators. It is assumed that divers generally move no more than 150 m from the location where they entered the water in a single dive (Hawkins et al 1999, Rouphael & Inglis 2002. Such frequently visited areas, where divers enter the water at marked and therefore consistent locations, are hereafter considered fished areas.…”

The effect of recreational SCUBA divers on the structural complexity and benthic assemblage of a Caribbean coral reef

“…are more resilient) and vice versa. For example, branching and leafy stony corals have little resistance to breakage and fragmentation by physical disturbance of divers and are often cited as the benthic organism most commonly broken by divers (Hawkins and Roberts 1992;Chadwick-Furrnan 1995;Rouphael and Inglis 2002). However, many branching and leafy corals recover more quickly following abrasion than massive corals (Meesters et al 1992;Hall 1997).…”