Due to the scarcity of the proper access point to the deep waters by divers and snorkelers, bays ... more Due to the scarcity of the proper access point to the deep waters by divers and snorkelers, bays and lagoons are used as sheltered marine areas in the southern Egyptian Red Sea and are represented very valuable recreational areas. With the recent booming in tourism along the Egyptian coast of the Red Sea, the sheltered bays and lagoon reefs are tremendously impacted by recreational SCUBA diving activities. Three bays with similar environmental and topographic characteristics, but with different levels of diving and snorkeling activities were selected to study the impacts of recreational SCUBA diving on sedimentation rate, substrate analysis, coral cover, diversity, coral recruitment and coral reef fish assemblages. In addition to the expected physical damage causes by incidental contacts to corals by divers, the results showed that increasing sedimentation rate as a result of intensive SCUBA diving also caused a serious impact on coral reef communities of the surveyed bays. Highest sedimentation rate was estimated at the over-dived site of the Marsa Um El-Gurifat (approximately 51,000 divers per year). Walking and standing of divers on the sea floor was disturbing the fine sediments of the bay floor, increasing turbidity and sedimentation rate on the nearby coral reefs of the bay. High sedimentation rate on the reefs of Marsa Um El-Gurifat caused the following: reduced the coral cover; overgrown soft coral that dominated coral cover, reduced the recruitment of new coral colonies, increased dead coral cover, increased the macroalgal cover especially on the reef flat areas, decreased the diversity of hard coral and coral reef fishes, shifted the fish assemblage toward higher occurrence of herbivore fishes comparing with corallivore and carnivore ones.
ARTICLE INFO ABSTRACT Article History Received: June 20, 2011 Accepted: July 15, 2011 Available o... more ARTICLE INFO ABSTRACT Article History Received: June 20, 2011 Accepted: July 15, 2011 Available online: Sept. 2011 ________________
Recently, annual swarm of invasive Erythrean schyphozoan RhopilemanomadicaGalil, 1990 appeared al... more Recently, annual swarm of invasive Erythrean schyphozoan RhopilemanomadicaGalil, 1990 appeared along Egyptian Mediterranean coasts causing beach closures and fishing problems. The present study conducted survey and field monitoring on R. nomadica during blooming season in the Egyptian Mediterranean coast throughout three consecutive years (2015-2017). Three main features of R. nomadica bloom were addressed; viz starting date, duration and maximum density of aggregation. In 2015, the bloom started on 28 July, and over the following two years the bloom starting date shifted earlier being 19 July in 2016 and 15 June in 2017. The duration of the bloom varied yearly giving the longest duration in 2017 when the bloom continued in high density for a month. The highest density of R. nomadica was about 896 medusae/1000 m3 in 2017. The medusae diameter ranged between 21 to 112 cm. The average bell diameter for each year displayed gradual increasing values over the years. The consistent annual...
The spawning season of 17 Acropora species was followed in the Egyptian Red Sea reefs. Synchroniz... more The spawning season of 17 Acropora species was followed in the Egyptian Red Sea reefs. Synchronized spawning was observed for 12 of these species three nights prior to the second spring full moon in 2012 and four nights prior to the second spring full moon in 2013. Development of oocyte size and color was followed. The largest oocytes were recorded for A. clathrata (562 μm), while the smallest recorded were from A. squarrosa (414 μm). A significant difference in oocyte size was detected between species. Five color stages were observed during oocyte maturation: white (immature), light-cream, cream, light-pink, and pink (mature). Estimations of polyp fecundity ranged from 11 oocytes per polyp in A. formosa to 32 oocytes per polyp in A. tenuis. The fecundity of polyps varied significantly between species, while no significant differences were detected between sites, years or colonies of the same species. The density of polyps per square centimeter of tissue varied significantly between...
Study of the effect of human impact and sheltering condition on corals and fish assemblages was c... more 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 unimpacte...
The spawning season of 17 Acropora species was followed in the Egyptian Red Sea reefs. Synchroniz... more The spawning season of 17 Acropora species was followed in the Egyptian Red Sea reefs. Synchronized spawning was observed for 12 of these species three nights prior to the second spring full moon in 2012 and four nights prior to the second spring full moon in 2013. Development of oocyte size and color was followed. The largest oocytes were recorded for A. clathrata (562 µm), while the smallest recorded were from A. squarrosa (414 µm). A significant difference in oocyte size was detected between species. Five color stages were observed during oocyte maturation: white (immature), light-cream, cream, light-pink, and pink (mature). Estimations of polyp fecundity ranged from 11 oocytes per polyp in A. formosa to 32 oocytes per polyp in A. tenuis. The fecundity of polyps varied significantly between species, while no significant differences were detected between sites, years or colonies of the same species. The density of polyps per square centimeter of tissue varied significantly between species, and ranged from 11.5 polyps/cm 2 for A. massawensis to 31 polyps/cm 2 for A. formosa. Estimated fecundity values ranged between 256 oocytes/cm 2 for A. arabensis to 627 oocytes/cm 2 for A. cytherea. The recorded changes in oocyte color and size during development could be a useful tool to predict spawning events. Improvements to our understanding of Acropora species fecundity can assist managers to develop more robust reef recovery practices to alleviate damage on reefs from natural or anthropogenic sources.
The present study introduce an overview on the cladal structure of Symbiodinium population associ... more The present study introduce an overview on the cladal structure of Symbiodinium population associated with some species of scleractinean corals and fire coral in the Egyptian Red Sea coast and discuss the possible consequences of recent climate changes on coral reefs. Cladal structure of Symbiodinium populations associated with eight keystone species of scleractinean corals and one species of fire coral that collected along Egyptian Red Sea coast, during 2012-2013, had been resolved based on 18S nrDNA and ITS2 genetic markers. Only Symbiodinium subclades C1 and A1 were identified from all examined species. Symbiodinium C1 was the dominant subclade that associated with 61% of coral samples. Results revealed that the studied pocilloporid corals were associated with Symbiodinium C1 and/or A1 while acroporids were only associated with Symbiodinium C1. The present data also indicated that Symbiodinium C1 occurred at high densities than A1 or A1+C1 combination. Because of the relative thermal susceptibility of clades C and A, the current study addresses that the recent climate changes may derive dramatic changes on community structure of coral reefs at the Red Sea. DOI : Coming Soon
The zooplankton play important roles in marine biogeochemical cycles and food webs, as they act a... more The zooplankton play important roles in marine biogeochemical cycles and food webs, as they act as a link for the energy transfer from lower to higher trophic levels and have a key role in the recycling and mediating of macronutrients (Stibor et al., 2004; Turner, 2004; Mitra et al., 2014a,b). During the past three decades the Egyptian coast of the Red Sea and the Gulf of Aqaba, including Sharm El-Sheikh has been exposed to intensive human activities, which exhibited pronounced effects on the topography, environmental characteristics and the biotic components of these regions. Numerous studies were carried out on the zooplankton of the Red Sea, either on the spatial distributions of the major ARTICLE INFO
Egyptian Journal of Aquatic Biology and Fisheries, Jul 8, 2018
The present study aimed to examine the morphological variations occur in the same species of some... more The present study aimed to examine the morphological variations occur in the same species of some sclerectinian corals inhabiting Red Sea and Arabian Gulf to establish basic understand the lineage between scleractinian coral species in such geographic region. 126 specimens of the most abundant sclerectinian corals inhabiting the Egyptian coasts along Red Sea and Gulf of Aqaba and Arabian Gulf were collected. Mico-and macro-morphological identification was used to identify and investigate coral species at selected sites. Eight species were recorded (Acropora pharaonis, Acropora humilis, Acropora digitefra, Pocillopora verrucosa, Stylophora pistillata, Porites harrisoni, Platygyra daedalea, Favia pallida) belong to six genera. Analysis of variance (ANOVA) has been made for the corallite and branch measurement with sites. The preset study revealed that corallite diameter are highly influenced by geographic distribution in all species except corallite of Stylophora pistillata. Branch diameter are highly influenced (p<0. 05) by geographic distribution only in Acropora humilis and Acropora digitefera, while Acropora pharaonis, Pocilliopora verrucosa and Stylophora pistillata did not vary among sites. Comparing specimens collected from Arabian Gulf with those from Red Sea and Gulf of Aqaba, corallite and branch measurements of Stylophora pistillata, Platygyra deadalea were very near and morphological characters were identical. Corallite and branch measurements of Favia pallida were very close at all locations. Only in Red Sea specimens (Fanous), costa and paliform was absent.
Journal of Environmental Science and Public Health
Scleractinian corals Phylogenetic studies have been shown that most taxa are not matched with the... more Scleractinian corals Phylogenetic studies have been shown that most taxa are not matched with their evolutionary histories. Using gross morphology as principal base, traditional taxonomy cannot solve the lack of well-defined and homologous characters that can describe scleractinian diversity sufficient. Scleractinian Coral species are hard to identify because of their morphological plasticity. DNA barcoding techniques were used to build molecular phylogenetic analysis to some common scleractinian species in Red Sea and Arabian Gulf. The phylogenetic analysis showed that Porites harrisoni, was clustered separate from other Porites sp collected from gene bank. While for Acropora digitefra genetic divergences were recorded between samples collected from the Red Sea and Gulf of Aqaba. Platygyra daeleda sample from Fanous (Red Sea) were distinct from other Platygyra daeleda samples same case were recorded with Pocillopora verrucosa samples. The DNA barcoding technique proves to be very useful in not only differentiating between species but also finding genetic diversity within species.
inear growth rates were measured for two species of coral namely, Acropora humilis and Millepora ... more inear 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.
The present study introduce an overview on the cladal structure of Symbiodinium population associ... more The present study introduce an overview on the cladal structure of Symbiodinium population associated with some species of scleractinean corals and fire coral in the Egyptian Red Sea coast and discuss the possible consequences of recent climate changes on coral reefs. Cladal structure of Symbiodinium populations associated with eight keystone species of scleractinean corals and one species of fire coral that collected along Egyptian Red Sea coast, during 2012-2013, had been resolved based on 18S nrDNA and ITS2 genetic markers. Only Symbiodinium subclades C1 and A1 were identified from all examined species. Symbiodinium C1 was the dominant subclade that associated with 61% of coral samples. Results revealed that the studied pocilloporid corals were associated with Symbiodinium C1 and/or A1 while acroporids were only associated with Symbiodinium C1. The present data also indicated that Symbiodinium C1 occurred at high densities than A1 or A1+C1 combination. Because of the relative the...
ABSTRACT This paper reviews management frameworks used in marine protected areas to limit the imp... more ABSTRACT This paper reviews management frameworks used in marine protected areas to limit the impact of SCUBA divers on coral assemblages, including the Carrying Capacity Approach and Limits of Acceptable Change. It notes their weaknesses, which can render them especially difficult to implement in developing countries. The paper proposes an alternative management framework that is procedurally and computationally simple, and can provide early warning of the deterioration of coral assemblages. With this approach, the abundance of coral injuries (broken branch tips and tissue abrasions) is monitored and compared concurrently at dive and reference sites. A requirement for further management action is triggered if the median abundance of coral injuries taken at a dive site equals or exceeds the 80th percentile of coral injuries estimated from reference sites. The primary assumption of this framework is that disturbance of a coral assemblage by divers manifests in a measurable increase in coral injuries before there is a decrease in the percent coverage of living coral. Other advantages are that it avoids the need to specify an absolute quantity considered ecologically important and the trigger criterion is regularly updated to reflect extraneous factors such as storm events.
Prior to any dredging operations of East Branch Harbour of Port-Said, the benthic marine ecology ... more Prior to any dredging operations of East Branch Harbour of Port-Said, the benthic marine ecology at this area was investigated. This pre-impact study included assessments of the environmental conditions and included salinity, oxygen concentration, chlorophyll “a”, nutrients concentration (phosphate, nitrite, nitrate), total suspended solids, concentration of heavy metals. The diversity of benthic biota is discussed in relation to the present and expected environmental status of the area. Such base-line data when combined with monitoring studies are essential for evaluating the undesirable impacts of harbour development that can threaten to marine life.
Recently, annual swarm of invasive Erythrean schyphozoan Rhopilema nomadica Galil, 1990 appeared ... more Recently, annual swarm of invasive Erythrean schyphozoan Rhopilema nomadica Galil, 1990 appeared along Egyptian Mediterranean coasts causing beach closures and fishing problems. The present study conducted survey and field monitoring on R. nomadica during blooming season in the Egyptian Mediterranean coast throughout three consecutive years (2015-2017). Three main features of R. nomadica bloom were addressed; viz starting date, duration and maximum density of aggregation. In 2015, the bloom started on 28 July, and over the following two years the bloom starting date shifted earlier being 19 July in 2016 and 15 June in 2017. The duration of the bloom varied yearly giving the longest duration in 2017 when the bloom continued in high density for a month. The highest density of R. nomadica was about 896 medusae/1000 m 3 in 2017. The medusae diameter ranged between 21 to 112 cm. The average bell diameter for each year displayed gradual increasing values over the years. The consistent annual R. nomadica blooming was attributed to the high level of eutrophication and ecosystem degradation occurred along the Mediterranean coast since last decades. The shifting in the annual bloom starting date and duration may reflect the adaptation of R. nomadica to the climate change effect on the Mediterranean Sea temperature. DOI: Coming Soon
Due to the scarcity of the proper access point to the deep waters by divers and snorkelers, bays ... more Due to the scarcity of the proper access point to the deep waters by divers and snorkelers, bays and lagoons are used as sheltered marine areas in the southern Egyptian Red Sea and are represented very valuable recreational areas. With the recent booming in tourism along the Egyptian coast of the Red Sea, the sheltered bays and lagoon reefs are tremendously impacted by recreational SCUBA diving activities. Three bays with similar environmental and topographic characteristics, but with different levels of diving and snorkeling activities were selected to study the impacts of recreational SCUBA diving on sedimentation rate, substrate analysis, coral cover, diversity, coral recruitment and coral reef fish assemblages. In addition to the expected physical damage causes by incidental contacts to corals by divers, the results showed that increasing sedimentation rate as a result of intensive SCUBA diving also caused a serious impact on coral reef communities of the surveyed bays. Highest sedimentation rate was estimated at the over-dived site of the Marsa Um El-Gurifat (approximately 51,000 divers per year). Walking and standing of divers on the sea floor was disturbing the fine sediments of the bay floor, increasing turbidity and sedimentation rate on the nearby coral reefs of the bay. High sedimentation rate on the reefs of Marsa Um El-Gurifat caused the following: reduced the coral cover; overgrown soft coral that dominated coral cover, reduced the recruitment of new coral colonies, increased dead coral cover, increased the macroalgal cover especially on the reef flat areas, decreased the diversity of hard coral and coral reef fishes, shifted the fish assemblage toward higher occurrence of herbivore fishes comparing with corallivore and carnivore ones.
ARTICLE INFO ABSTRACT Article History Received: June 20, 2011 Accepted: July 15, 2011 Available o... more ARTICLE INFO ABSTRACT Article History Received: June 20, 2011 Accepted: July 15, 2011 Available online: Sept. 2011 ________________
Recently, annual swarm of invasive Erythrean schyphozoan RhopilemanomadicaGalil, 1990 appeared al... more Recently, annual swarm of invasive Erythrean schyphozoan RhopilemanomadicaGalil, 1990 appeared along Egyptian Mediterranean coasts causing beach closures and fishing problems. The present study conducted survey and field monitoring on R. nomadica during blooming season in the Egyptian Mediterranean coast throughout three consecutive years (2015-2017). Three main features of R. nomadica bloom were addressed; viz starting date, duration and maximum density of aggregation. In 2015, the bloom started on 28 July, and over the following two years the bloom starting date shifted earlier being 19 July in 2016 and 15 June in 2017. The duration of the bloom varied yearly giving the longest duration in 2017 when the bloom continued in high density for a month. The highest density of R. nomadica was about 896 medusae/1000 m3 in 2017. The medusae diameter ranged between 21 to 112 cm. The average bell diameter for each year displayed gradual increasing values over the years. The consistent annual...
The spawning season of 17 Acropora species was followed in the Egyptian Red Sea reefs. Synchroniz... more The spawning season of 17 Acropora species was followed in the Egyptian Red Sea reefs. Synchronized spawning was observed for 12 of these species three nights prior to the second spring full moon in 2012 and four nights prior to the second spring full moon in 2013. Development of oocyte size and color was followed. The largest oocytes were recorded for A. clathrata (562 μm), while the smallest recorded were from A. squarrosa (414 μm). A significant difference in oocyte size was detected between species. Five color stages were observed during oocyte maturation: white (immature), light-cream, cream, light-pink, and pink (mature). Estimations of polyp fecundity ranged from 11 oocytes per polyp in A. formosa to 32 oocytes per polyp in A. tenuis. The fecundity of polyps varied significantly between species, while no significant differences were detected between sites, years or colonies of the same species. The density of polyps per square centimeter of tissue varied significantly between...
Study of the effect of human impact and sheltering condition on corals and fish assemblages was c... more 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 unimpacte...
The spawning season of 17 Acropora species was followed in the Egyptian Red Sea reefs. Synchroniz... more The spawning season of 17 Acropora species was followed in the Egyptian Red Sea reefs. Synchronized spawning was observed for 12 of these species three nights prior to the second spring full moon in 2012 and four nights prior to the second spring full moon in 2013. Development of oocyte size and color was followed. The largest oocytes were recorded for A. clathrata (562 µm), while the smallest recorded were from A. squarrosa (414 µm). A significant difference in oocyte size was detected between species. Five color stages were observed during oocyte maturation: white (immature), light-cream, cream, light-pink, and pink (mature). Estimations of polyp fecundity ranged from 11 oocytes per polyp in A. formosa to 32 oocytes per polyp in A. tenuis. The fecundity of polyps varied significantly between species, while no significant differences were detected between sites, years or colonies of the same species. The density of polyps per square centimeter of tissue varied significantly between species, and ranged from 11.5 polyps/cm 2 for A. massawensis to 31 polyps/cm 2 for A. formosa. Estimated fecundity values ranged between 256 oocytes/cm 2 for A. arabensis to 627 oocytes/cm 2 for A. cytherea. The recorded changes in oocyte color and size during development could be a useful tool to predict spawning events. Improvements to our understanding of Acropora species fecundity can assist managers to develop more robust reef recovery practices to alleviate damage on reefs from natural or anthropogenic sources.
The present study introduce an overview on the cladal structure of Symbiodinium population associ... more The present study introduce an overview on the cladal structure of Symbiodinium population associated with some species of scleractinean corals and fire coral in the Egyptian Red Sea coast and discuss the possible consequences of recent climate changes on coral reefs. Cladal structure of Symbiodinium populations associated with eight keystone species of scleractinean corals and one species of fire coral that collected along Egyptian Red Sea coast, during 2012-2013, had been resolved based on 18S nrDNA and ITS2 genetic markers. Only Symbiodinium subclades C1 and A1 were identified from all examined species. Symbiodinium C1 was the dominant subclade that associated with 61% of coral samples. Results revealed that the studied pocilloporid corals were associated with Symbiodinium C1 and/or A1 while acroporids were only associated with Symbiodinium C1. The present data also indicated that Symbiodinium C1 occurred at high densities than A1 or A1+C1 combination. Because of the relative thermal susceptibility of clades C and A, the current study addresses that the recent climate changes may derive dramatic changes on community structure of coral reefs at the Red Sea. DOI : Coming Soon
The zooplankton play important roles in marine biogeochemical cycles and food webs, as they act a... more The zooplankton play important roles in marine biogeochemical cycles and food webs, as they act as a link for the energy transfer from lower to higher trophic levels and have a key role in the recycling and mediating of macronutrients (Stibor et al., 2004; Turner, 2004; Mitra et al., 2014a,b). During the past three decades the Egyptian coast of the Red Sea and the Gulf of Aqaba, including Sharm El-Sheikh has been exposed to intensive human activities, which exhibited pronounced effects on the topography, environmental characteristics and the biotic components of these regions. Numerous studies were carried out on the zooplankton of the Red Sea, either on the spatial distributions of the major ARTICLE INFO
Egyptian Journal of Aquatic Biology and Fisheries, Jul 8, 2018
The present study aimed to examine the morphological variations occur in the same species of some... more The present study aimed to examine the morphological variations occur in the same species of some sclerectinian corals inhabiting Red Sea and Arabian Gulf to establish basic understand the lineage between scleractinian coral species in such geographic region. 126 specimens of the most abundant sclerectinian corals inhabiting the Egyptian coasts along Red Sea and Gulf of Aqaba and Arabian Gulf were collected. Mico-and macro-morphological identification was used to identify and investigate coral species at selected sites. Eight species were recorded (Acropora pharaonis, Acropora humilis, Acropora digitefra, Pocillopora verrucosa, Stylophora pistillata, Porites harrisoni, Platygyra daedalea, Favia pallida) belong to six genera. Analysis of variance (ANOVA) has been made for the corallite and branch measurement with sites. The preset study revealed that corallite diameter are highly influenced by geographic distribution in all species except corallite of Stylophora pistillata. Branch diameter are highly influenced (p<0. 05) by geographic distribution only in Acropora humilis and Acropora digitefera, while Acropora pharaonis, Pocilliopora verrucosa and Stylophora pistillata did not vary among sites. Comparing specimens collected from Arabian Gulf with those from Red Sea and Gulf of Aqaba, corallite and branch measurements of Stylophora pistillata, Platygyra deadalea were very near and morphological characters were identical. Corallite and branch measurements of Favia pallida were very close at all locations. Only in Red Sea specimens (Fanous), costa and paliform was absent.
Journal of Environmental Science and Public Health
Scleractinian corals Phylogenetic studies have been shown that most taxa are not matched with the... more Scleractinian corals Phylogenetic studies have been shown that most taxa are not matched with their evolutionary histories. Using gross morphology as principal base, traditional taxonomy cannot solve the lack of well-defined and homologous characters that can describe scleractinian diversity sufficient. Scleractinian Coral species are hard to identify because of their morphological plasticity. DNA barcoding techniques were used to build molecular phylogenetic analysis to some common scleractinian species in Red Sea and Arabian Gulf. The phylogenetic analysis showed that Porites harrisoni, was clustered separate from other Porites sp collected from gene bank. While for Acropora digitefra genetic divergences were recorded between samples collected from the Red Sea and Gulf of Aqaba. Platygyra daeleda sample from Fanous (Red Sea) were distinct from other Platygyra daeleda samples same case were recorded with Pocillopora verrucosa samples. The DNA barcoding technique proves to be very useful in not only differentiating between species but also finding genetic diversity within species.
inear growth rates were measured for two species of coral namely, Acropora humilis and Millepora ... more inear 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.
The present study introduce an overview on the cladal structure of Symbiodinium population associ... more The present study introduce an overview on the cladal structure of Symbiodinium population associated with some species of scleractinean corals and fire coral in the Egyptian Red Sea coast and discuss the possible consequences of recent climate changes on coral reefs. Cladal structure of Symbiodinium populations associated with eight keystone species of scleractinean corals and one species of fire coral that collected along Egyptian Red Sea coast, during 2012-2013, had been resolved based on 18S nrDNA and ITS2 genetic markers. Only Symbiodinium subclades C1 and A1 were identified from all examined species. Symbiodinium C1 was the dominant subclade that associated with 61% of coral samples. Results revealed that the studied pocilloporid corals were associated with Symbiodinium C1 and/or A1 while acroporids were only associated with Symbiodinium C1. The present data also indicated that Symbiodinium C1 occurred at high densities than A1 or A1+C1 combination. Because of the relative the...
ABSTRACT This paper reviews management frameworks used in marine protected areas to limit the imp... more ABSTRACT This paper reviews management frameworks used in marine protected areas to limit the impact of SCUBA divers on coral assemblages, including the Carrying Capacity Approach and Limits of Acceptable Change. It notes their weaknesses, which can render them especially difficult to implement in developing countries. The paper proposes an alternative management framework that is procedurally and computationally simple, and can provide early warning of the deterioration of coral assemblages. With this approach, the abundance of coral injuries (broken branch tips and tissue abrasions) is monitored and compared concurrently at dive and reference sites. A requirement for further management action is triggered if the median abundance of coral injuries taken at a dive site equals or exceeds the 80th percentile of coral injuries estimated from reference sites. The primary assumption of this framework is that disturbance of a coral assemblage by divers manifests in a measurable increase in coral injuries before there is a decrease in the percent coverage of living coral. Other advantages are that it avoids the need to specify an absolute quantity considered ecologically important and the trigger criterion is regularly updated to reflect extraneous factors such as storm events.
Prior to any dredging operations of East Branch Harbour of Port-Said, the benthic marine ecology ... more Prior to any dredging operations of East Branch Harbour of Port-Said, the benthic marine ecology at this area was investigated. This pre-impact study included assessments of the environmental conditions and included salinity, oxygen concentration, chlorophyll “a”, nutrients concentration (phosphate, nitrite, nitrate), total suspended solids, concentration of heavy metals. The diversity of benthic biota is discussed in relation to the present and expected environmental status of the area. Such base-line data when combined with monitoring studies are essential for evaluating the undesirable impacts of harbour development that can threaten to marine life.
Recently, annual swarm of invasive Erythrean schyphozoan Rhopilema nomadica Galil, 1990 appeared ... more Recently, annual swarm of invasive Erythrean schyphozoan Rhopilema nomadica Galil, 1990 appeared along Egyptian Mediterranean coasts causing beach closures and fishing problems. The present study conducted survey and field monitoring on R. nomadica during blooming season in the Egyptian Mediterranean coast throughout three consecutive years (2015-2017). Three main features of R. nomadica bloom were addressed; viz starting date, duration and maximum density of aggregation. In 2015, the bloom started on 28 July, and over the following two years the bloom starting date shifted earlier being 19 July in 2016 and 15 June in 2017. The duration of the bloom varied yearly giving the longest duration in 2017 when the bloom continued in high density for a month. The highest density of R. nomadica was about 896 medusae/1000 m 3 in 2017. The medusae diameter ranged between 21 to 112 cm. The average bell diameter for each year displayed gradual increasing values over the years. The consistent annual R. nomadica blooming was attributed to the high level of eutrophication and ecosystem degradation occurred along the Mediterranean coast since last decades. The shifting in the annual bloom starting date and duration may reflect the adaptation of R. nomadica to the climate change effect on the Mediterranean Sea temperature. DOI: Coming Soon
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Papers by Mahmoud Hanafy