Although the rapidly expanding tourism industry is considered an extremely important economic activity, it caused increasing pressure on coral reefs of Egypt. Damage occurs from both direct and indirect impacts of tou...Although the rapidly expanding tourism industry is considered an extremely important economic activity, it caused increasing pressure on coral reefs of Egypt. Damage occurs from both direct and indirect impacts of tourism activities on coral communities. The Gulf of Suez has increasing of resorts from 8 at 2000 to 31 at 2014. This affected the coral communities along the area of study leads to a decrease in coral areas from 960 m2 at 2000 to 750 m2 at 2014, number of coral species from 21 species at 2000 to only 14 species at 2014, percentage cover of life coral from 46.4% at 2000 to 10.6% at 2014;on contrary, dead coral increased from 23.8% to 47.9% at the same period. This accompanied with an increase in the percentage of the algal cover from 8.6% at 2000 to 19.4% at 2014. The statistical analysis revealed a high correlation between the increased tourism activities and the coral status variables measured during the study. The data obtained showed high significant positive and negative correlation between the different variables that determined according to the effect of the different variables on each other and the relation between them. The simple linear regression statistical analyses showed a significant effect of tourism activities on the coral status, the analyses indicated that each increase in number of resorts by one resort leads to significant decrease in total coral area at the site by 0.9%, the analysis also showed that 80% of that decrease referred to the effect of tourism activities and 20% referred to other reasons. The analysis of variance (ANOVA) divided the recoded coral species into three categories, the first is soft corals which recorded significant increase in percentage cover from 2000 to 2014, the second is three species that recorded insignificant difference during the period of study, while the third category include most of the recorded species and they showed significant decrease in their percentage cover along time of study. The data obtained illustrated that all the investigated coral parameters are affected by the increasing tourism activities.展开更多
In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Is...In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands （44.55%±11.10% cover） fol-lowed by tabular forms in the Doga Islands （ranging between 18%±6.47% and 18.30%±9.47% cover）. Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area （58.89%±15.11% cover） followed by the Jeddah coast （24.76%±14.04% cover）. The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah （10.70%±8.21%） and A1-Wajh （9.81%±6.69%）. The live coral cover （including both Scleractinian and non-Scleractinian corals） of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acro- porid corals was greater in the southern region than in the northem and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah （Northem region） and the second one comprised the middle and southem regions （Jeddah to Farassan Islands）, and one outlier Rabigh.展开更多
Our research objective was to expand the very limited knowledgebase pertaining to the ecology of fringing coral reefs in the Gulf of Suez, Egypt. Specifically, determine dominant coral species and investigate why this...Our research objective was to expand the very limited knowledgebase pertaining to the ecology of fringing coral reefs in the Gulf of Suez, Egypt. Specifically, determine dominant coral species and investigate why this reef is capable of surviving at such a high-latitude and extreme harsh environment. Data collection included annual reef surveys, randomized quadrat sampling, five permanent video transects and in situ seawater temperature. Of the known Gulf of Suez 35 taxa, only six (Acropora humilis, A. microclados, A. hemprichii, Litophyton arboretum, Stylophora pistillata, Porites columna, and P. plantulata), compose 94% of the reef's coral cover. Coral dominance across species shifted drastically during the study period. However, the six coral dominance remained unchanged, while some decreased others increased. These six coral taxa regularly experience daily changes in seawater temperature and seasonal variations that exceed These extreme temperatures variation and the fact that only six coral taxa dominance remained unchanged, suggest that these corals may have developed a mechanism to cope with extreme seawater temperatures as evidenced by their continued growth and survival over the study period. We speculate that species dominance shift occurred largely as a result of a local oil spill rather than exposure to extreme temperatures. Further scrutiny of these species and the mechanisms by which they are able to thrive is recommended, as they hold the potential to benefit other coral communities as a resilient transplant species and model for understanding coral survivability in extreme environmental conditions.展开更多
Annual skeletal extension rates of the sclera-actinian corals Porites species were investigated in 32 colonies from the northern Gulf of Aqaba fringing reef at various depths (1 - 42 m). All corals reveal clear and re...Annual skeletal extension rates of the sclera-actinian corals Porites species were investigated in 32 colonies from the northern Gulf of Aqaba fringing reef at various depths (1 - 42 m). All corals reveal clear and regular skeletal density banding patterns. Results showed that the high-density annual growth bands were formed during winter and the low-density annual growth bands during summer. The mean annual extension rates of the studied corals reveal a large inter-colony variability with values ranged between 2.36 to 20.0 mm/year. While a general trend of decreasing coral extension rate with depth was observed and best explained by a simple exponential model, the rates clustered into two groups: 10.86 ± 2.54 mm/year in water depths less than 10 m, and 5.23 ± 1.99 mm/year below 12 m. Light intensity seems to be the primary environmental factor responsible for decreasing coral extension rate with depth since the effect of other environmental parameters could be neglected from the Gulf of Aqaba. Time series record of the mean annual coral extension rate showed a slight increasing linear trend which could be linked to increase seawater temperature over the period of time represented.展开更多
文摘Although the rapidly expanding tourism industry is considered an extremely important economic activity, it caused increasing pressure on coral reefs of Egypt. Damage occurs from both direct and indirect impacts of tourism activities on coral communities. The Gulf of Suez has increasing of resorts from 8 at 2000 to 31 at 2014. This affected the coral communities along the area of study leads to a decrease in coral areas from 960 m2 at 2000 to 750 m2 at 2014, number of coral species from 21 species at 2000 to only 14 species at 2014, percentage cover of life coral from 46.4% at 2000 to 10.6% at 2014;on contrary, dead coral increased from 23.8% to 47.9% at the same period. This accompanied with an increase in the percentage of the algal cover from 8.6% at 2000 to 19.4% at 2014. The statistical analysis revealed a high correlation between the increased tourism activities and the coral status variables measured during the study. The data obtained showed high significant positive and negative correlation between the different variables that determined according to the effect of the different variables on each other and the relation between them. The simple linear regression statistical analyses showed a significant effect of tourism activities on the coral status, the analyses indicated that each increase in number of resorts by one resort leads to significant decrease in total coral area at the site by 0.9%, the analysis also showed that 80% of that decrease referred to the effect of tourism activities and 20% referred to other reasons. The analysis of variance (ANOVA) divided the recoded coral species into three categories, the first is soft corals which recorded significant increase in percentage cover from 2000 to 2014, the second is three species that recorded insignificant difference during the period of study, while the third category include most of the recorded species and they showed significant decrease in their percentage cover along time of study. The data obtained illustrated that all the investigated coral parameters are affected by the increasing tourism activities.
文摘In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands （44.55%±11.10% cover） fol-lowed by tabular forms in the Doga Islands （ranging between 18%±6.47% and 18.30%±9.47% cover）. Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area （58.89%±15.11% cover） followed by the Jeddah coast （24.76%±14.04% cover）. The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah （10.70%±8.21%） and A1-Wajh （9.81%±6.69%）. The live coral cover （including both Scleractinian and non-Scleractinian corals） of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acro- porid corals was greater in the southern region than in the northem and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah （Northem region） and the second one comprised the middle and southem regions （Jeddah to Farassan Islands）, and one outlier Rabigh.
文摘Our research objective was to expand the very limited knowledgebase pertaining to the ecology of fringing coral reefs in the Gulf of Suez, Egypt. Specifically, determine dominant coral species and investigate why this reef is capable of surviving at such a high-latitude and extreme harsh environment. Data collection included annual reef surveys, randomized quadrat sampling, five permanent video transects and in situ seawater temperature. Of the known Gulf of Suez 35 taxa, only six (Acropora humilis, A. microclados, A. hemprichii, Litophyton arboretum, Stylophora pistillata, Porites columna, and P. plantulata), compose 94% of the reef's coral cover. Coral dominance across species shifted drastically during the study period. However, the six coral dominance remained unchanged, while some decreased others increased. These six coral taxa regularly experience daily changes in seawater temperature and seasonal variations that exceed These extreme temperatures variation and the fact that only six coral taxa dominance remained unchanged, suggest that these corals may have developed a mechanism to cope with extreme seawater temperatures as evidenced by their continued growth and survival over the study period. We speculate that species dominance shift occurred largely as a result of a local oil spill rather than exposure to extreme temperatures. Further scrutiny of these species and the mechanisms by which they are able to thrive is recommended, as they hold the potential to benefit other coral communities as a resilient transplant species and model for understanding coral survivability in extreme environmental conditions.
文摘Annual skeletal extension rates of the sclera-actinian corals Porites species were investigated in 32 colonies from the northern Gulf of Aqaba fringing reef at various depths (1 - 42 m). All corals reveal clear and regular skeletal density banding patterns. Results showed that the high-density annual growth bands were formed during winter and the low-density annual growth bands during summer. The mean annual extension rates of the studied corals reveal a large inter-colony variability with values ranged between 2.36 to 20.0 mm/year. While a general trend of decreasing coral extension rate with depth was observed and best explained by a simple exponential model, the rates clustered into two groups: 10.86 ± 2.54 mm/year in water depths less than 10 m, and 5.23 ± 1.99 mm/year below 12 m. Light intensity seems to be the primary environmental factor responsible for decreasing coral extension rate with depth since the effect of other environmental parameters could be neglected from the Gulf of Aqaba. Time series record of the mean annual coral extension rate showed a slight increasing linear trend which could be linked to increase seawater temperature over the period of time represented.
