A coral damage index and its application to diving sites in the Egyptian Red Sea

A coral damage index (CDI) is provided, to screen sites to obtain a perspec tive on the extent and severity of physical damage to coral. Sites are list ed as "hot spots" if in any transect the percent of broken coral colonies ( BCC) is greater than or equal to 4% or if the percent cover of coral rubble (CR) is greater than or equal to 3%. To demonstrate its utility, the CDI i s applied to a real-life management situation off Hurghada and Safaga, Egyp t in the Red Sea. The extent of corral damage covered all four diving sites , Forty percent of all the transects were "hot spots" that required managem ent action. Thirty-one percent of the 16 "hot spot" transects were identifi ed by both broken coral and rubble criteria, 25% by only broken coral crite rion and 44% by only coral rubble criterion of the CDI, suggesting that pas t breakage was responsible for most of the observed damage. Sixty-three per cent of the "hot spot" transects were at 4 m depth versus 37% at 8 m depth, suggesting that most of the damage was caused by anchors dragging across t he reef in shallow water. The severity of coral damage, reflected by CR, wa s the greatest at Small Giftun in transect 5 at 4 m depth (333% above the C DI). EI Fanous experienced the most severe degree of broken coral damage (3 25% above the CDI) at 8m depth along transect 2. Estimates of the number of dives per year show diving carrying capacities for El Fanous, Gotta Abu Ra mada, Ras Abu Soma and Small Giftun being exceeded by large amounts. The CD I can be used globally to; gauge the severity and extent of damage, focus m anagers on areas that need mooring buoys and associated dive site managemen t programs, and provide a starting point from which to focus more detailed coral reef assessments and restoration programs.