ABSTRACTinear growth rates were measured for two species of coral namely, Acropora humilis and Millepora platyphylla in Hurghada during the period from autumn 2006 to summer 2007. In addition, the rates of recovery in man-made lesion in M. platyphylla were estimated on seasonal basis. The linear growth rates of A. humils varied significantly according to the sheltering condition, with an overall mean of 8.89 and 6.98mm/year in exposed and sheltered sites. The highest linear growth rate of A. humilis was estimated at the exposed site of Gotta Abu Ramada, being 9.17mm/year, while the lowest rate of 6.61mm/year was recorded at the sheltered site of El-Fanadir Reef. The seasonal linear growth rates of M. platyphylla were affected significantly by the sheltering condition, and non-significantly by seasons. The estimated annual growth rates of M. platyphylla at the exposed sites averaged higher value of 15.65mm/year compared to 11.29mm/year at the sheltered sites. On the seasonal level, the highest overall mean of growth rates was recorded in spring, while the lowest mean was in autumn, being 3.72 and 3.06mm/season, respectively.The rates of diametric lesions recovery of M. platyphylla varied significantly according to seasons and non-significantly according to sheltering condition. The fastest recovery was recorded in summer, while the lowest recovery was in winter. For instance, the lesions of 3847mm 2 area each, recovered completely within 6 weeks in summer, while the same lesions area were not recovered completely after 12 weeks in winter.

Twenty nine sites on the reef of the area between House Reef Fantazia Resort to House Reef of Shams Alam Resort, south to city of Marsa Alam, were surveyed. The eleven key resilience factors set by McClanahan et al. (2012) were used to evaluate our studied Reef areas. The resilience rank equals the sum of the resistance rank and recovery rank. The highest resistance ranks 2.66 and the lowest one 2.06 recorded in sites 27 and 28, respectively, while the recovery rank ranged between 1.69 and 2.75 in sites 29 and 26 respectively. Dependably, the resilience rank ranged between 3.86 and 5.15 in sites 29 and 19, respectively. Generally, the sites with high recruitment colonies, coral resistance species, herbivores fishes biomass, and lower algal cover, human impacts had higher resilience rank than the others sites.

Study of the effect of human impact and sheltering condition on corals and fish assemblages was carried out in twenty nine reef sites at the area between Marsa Umm El-Grifate and Marsa Shuna, Red sea. Total living covers, total coral cover, and total recruitment colonies were recorded and exhibited higher percentages of occurrence on the exposed and un-impacted sites than on the sheltered and impacted ones. In contrary, the covers of algae, dead and bleached coral colonies were found to be higher on the sheltered and impacted reefs than on the exposed and un-impacted ones. In total, 117 fish species belong to 24 families were recorded. Although, carnivore fish were dominating the food web, the most abundant groups were found to be herbivore and planktivore fishes. Total fish abundance was higher in the shelter sites than in the exposed ones, while the abundance of herbivores, carnivores, and piscivores were higher in the sheltered and impacted sites than in the exposed and unimpacted ones. Total coral cover and total recruitments were negatively correlated to algal cover. Total fish abundance was positively correlated to total living cover and negatively correlated to total coral cover. Herbivores fish abundance was positively correlated to total coral cover and total recruitments, but it was negatively correlated to algal cover. Moreover, planktivores fishes were negatively correlated to the total coral cover and total recruitments. This study strongly recommended to organize the fishing activities along the southern Red Sea, in addition to regulate the rabid coastal development to this part of the Red Sea.