Higher number of broken coral heads
In an abstract from a paper produced by the Department of Marine Biology in the University of Vienna, studies on the impact of scuba divers in the northern parts of the Red Sea demonstrate how scuba diving threatens coral reef systems.
The paper says that reef systems in Dahab, Egypt, are among the world's most dived reefs (30,000 plus a year). The scientists from this university compared frequently dived sites, to sites with little or no diving. It says that benthic (bottom) communities and the condition of corals were examined by the point intercept sampling method in the reef crest zone (3 meters) and reef slope zone (12 meters). Based on a visual census method, there was an abundance of corallivorous and herbivorous fish. Zones subject to intensive Scuba diving activity showed a significantly higher number of broken coral heads and also a lower population of coral. The reef crest coral communities were significantly more affected and up to 95% of the broken coral was branching coral.
For the moment, the abundance of fish did not seem affected however the report says that continued high impact of scuba divers will endanger coral cover in the long term which will in turn affect the fish population.
It was suggested that the number of dives per year be reduced and also the introduction of ecologically sustainable dive plans would be essential to conserve the aesthetic and ecological properties of these dive sites. It was also mentioned that education of dive guides and the recreational divers will form an essential part of a programme of sustainability.