Search

The diversity and abundance of the invertebrates associated with two different abundant macroalgal species (Acanthophora and Padina) north of Jeddah coastal waters on the central Red Sea were studied during summer and winter seasons. Seven major groups belonging to 18 families of invertebrates were observed during this study. The most abundant invertebrate taxa were crustaceans followed by molluscs and polychaetes. The numerical density of communities associated with the two macroalgal species was higher in summer than in winter. Acanthophora hosted higher counts than those associated with Padina during summer and winter. Significant seasonal variations were observed in the abundance of isopods and decapods. Overall, this study indicated that marine macroalgae inhabiting in Jeddah coastal waters are acting as a refugia for marine invertebrates thereby supporting the coastal biodiversity. [ABSTRACT FROM AUTHOR]

The present study uses benthic foraminiferal abundance and diversity indices in the coastal bottom sediments of the Farasan Island, Southern Cornich of Jeddah (SCJ) and Rabigh areas, Saudi Arabia to identify the ecological controls on their distribution. A total of 20 recent sediment samples were collected from the studied sites. Grain size analysis, CaCO3 content and organic matter were determined. Multivariate analyses were applied to test and represent the diversity indices and distribution of benthic foraminiferal assemblage. Two main benthic foraminiferal assemblages; A and B have been distinguished. The assemblage-A includes a high abundance of T. trigonula (33%), S. communis (30%), Q. bosciana (21%), E. striatopunctatum (18%) with low diversity indices in the Rabigh coastal sediments indicating high ecological stress. The Farasan ecosystem is dominated by sub-assemblage-B1 P. planatus (55%), S. orbiculus (27%), N. calcar (15%), Q. limbata (14%), which totally ranges between 60%-82%, indicating a highly oxic marine environment and normal ecology stress. Sub-assemblage-B2 such as P. planatus (39%),C. hemprichii (26%), V. neostriata (15%),Q. costata (10%) dominate the Southern Corniche of Jeddah (SCJ) with relatively high diversity indices, indicating moderate stress ecology or unstable environmental conditions.The cluster and the canonical correspondence analyses (CCA) indicated that the distribution and diversity pattern of benthic foraminifera are controlled by the enrichment of organic matters, CaCO3 contents, and sediments grain size characteristics. The concept of differentiation between these ecosystems is probably related to several factors, such as seasonal flash floods carrying a considerable amount of dissolved nutrients and mangrove communities on the Rabigh coast. In contrast, it is negligible on the south Jeddah coast and absence on Farasan Island. [ABSTRACT FROM AUTHOR]

The Al-Salam Lagoon is one of the recreational sites along the Jeddah coast, showing the environmental impacts of urbanization along the coast. A sediment core (220 cm) was collected from the intertidal zone to evaluate the heavy metals (Fe, Mn, Cr, Ni, Cu, Zn, and Pb) and geochemical indices (contamination factor, geo-accumulation index, and pollution load index). In the organ-ic-rich muddy sediments (0–100 cm), there is a high metals content and a pollution load index of ~3, indicting anthropogenic impacts with high Cu contamination (CF:12) and moderate Fe, Mn, Cr, Ni, Zn, and Pb contamination (CF: geo trends indicate a common pollutant source and pollution load variations over time. In the sediment section (70–40 cm), a high organic matter, metal concentration, CF, Igeo, and PLI value (≥5) suggest an uncontrolled pollution load. The decreased and stable trends of environmental indicators toward surface sediments suggest measures taken to control the pollution along the Jeddah coast. Below 110 cm, the carbonate-rich sediments have low organic matter and metals, showing an unpolluted depositional environment. The negative geo-accumulation index implies a geogenic source and indicates no anthropogenic impacts as inferred from low (~1.0) CF and PLI.

Contamination with heavy metals in industrial wastewater of many tanneries and metal industries is increasing and dangerous problem. Red sea was habited by diverse groups of marine macroalgae with different economic importance, as feed, fodder and medicine. The biosorption ability of some red sea algae for lead ions was poorly studied. This study aimed to study the removal of dangerous heavy metal and some human pathogens by dried macroalgae collected from Jeddah Coast. The tested algal species were belonging to Chlorophyta (two species named Halimeda opuntia and Ulva lactuca), Phaeophyta (two species named Dictyota dichotoma and Sargassum muticum), and Rhodophyta (Digenea simplex). Ulva and Sargassum were the most dominant genera in the collecton area of the red sea. The dead algal mass of all tested macroalgae have the ability to absorb lead from solutions which is one of the most dangerous heavy metals. The green algal species, Ulva lactuca showed the best removal level of lead followed by the red algal species, Digenea simplex. The removal percentages of lead by Halimeda opuntia, Dictyota dichotoma and Sargassum muticum were nearly the same. Thus, Ulva lactuca was selected for detailed studies. Metal sorption included binding on the algal cell surface and to intracellular ligands. Various pretreatments enhance metal sorption capacity of algae. Maximum adsorption of lead by Ulva powder was obtained at 45°C and pH 4. Percentage of lead adsorption was about 100% by Ulva dry mass, suspended in lead solution (1000 mg/l) at pH 4 or pH 5, while the percentage was decreased to 40% and 10% at pH 4 and pH 5 at 5000 mg/l, respectively, which means at pH 5, high lead concentrations, the removal process is decreased. Maximum removal of lead by Ulva dry mass was obtained after 6 hrs of incubation at static conditions. Increasing shaking rate decreased biosorption process. It is clear that, in the biosorption process, increasing the weight of the used Ulva dry mass, enhanced removal process and maximum removal percentage was obtained using 1 g dry mass/l, while the lowest was obtained for 0.12 g/l. The antimicrobial activities of the tested algal extract against different microorganisms were determined. Maximum growth inhibition was recorded by aqueous extract of Ulva for both Escherichia coli and Aspergillus niger, thus they were used as control test organisms for both bacteria and fungi. It was clear that, the effect of Ulva extract was excellent on gram-negative bacteria compared to gram-positive bacteria with MIC ranged from 30-40 µg/ml for gram-negative bacteria and 60-65 µg/ml for gram-positive bacteria. Moderate antifungal activities were recorded against Candida albicans and Alternaria alternata compared to Aspergillus niger. In conclusion, using Ulva dry mass to remove lead from contaminated solutions is effective and low-cost method. Moreover, Ulva extract inhibited certain bacterial and fungal pathogens, thus, Ulva dry mass can be used to clean wastewater from heavy metals and some pathogens. [ABSTRACT FROM AUTHOR]

A study was conducted to find out the possible reasons of fish killing at the Jeddah Coast, the Red Sea, Saudi Arabia. There are many factors for a sudden fish die-off in a water body such as toxic discharges, low dissolved oxygen (DO), temperature, salinity, pH, ammonia, turbidity, pesticides, toxins, and diseases. The study was carried out to find out the reasons of sudden fish killing. Therefore, physico-chemical and biological parameters, and postmortem, especially the gills and gut content of dead fishes were studied. The dead Tilapia tilapia (Tilapia), Chanos chano (Milkfish) and Parapriacanthus ransonneti (Glassfish) were found with wide mouth opened, skin with huge mucous and a bent back head, flared gills lesion and reddish sanguinary. The water temperature (°C), DO, salinity and pH varied from 24.8 to 26.2 (°C), 0.10 to 0.35 mg/L, 7.41 to 18.77 ppt and 7.31 to 7.64, respectively. Water column microalgal cell abundance varied from 78×10³ to 147×10³cells/L, with an average of 97.2×10³ cells/L. The abundance of microalgae in gut was 137.30×10³, 105.30×10³ and 204.14×10³ cells/g of gut of Tilapia, milkfish and glassfish, respectively. In gut, microalgae of Bacillariophyceae were 60, 81 and 61% among total microalgae in gut content of Tilapia, Milkfish and Glassfish, respectively. There was no microalga on gills. The salinity was 50 to 79% lower than that of the normal salinity of the Red Sea due to rain on previous day of fish killing. Sudden decrease of salinity and nearly zero DO concentration might be the reasons of killing fish by creating osmotically imbalance and suffocation of fishes. Additionally, due to low pH, huge mucous covered the gills filaments which might have created difficulties for respiration. Thus, the fish killing incident might have occurred by synergetic effects of different physico-chemical factors. [ABSTRACT FROM AUTHOR]

Many specific problems in the coastal zones require an accurate description of the wave field and knowledge of wave parameters. The studies on the spectral characteristics of wind-waves in the Red Sea are very much limited. In this study, the spectral characteristics of nearshore waves in the central Red Sea, specifically the Jeddah coast has been investigated utilizing a third generation spectral wave model, SWAN. The model results were validated against the available measured data. The seasonal and monthly characteristics and the diurnal variability of wave spectra were analysed and discussed. The wave transformation between deep, intermediate and shallow water depths were assessed at three transects – northern, central and southern regions off Jeddah. The results indicate that multi-directional swells are present in the Jeddah nearshore regions, which are propagated from the northern and southern Red Sea. The diurnal variability in the wave spectra is persistent throughout the year, although it fluctuates among the seasons according to the prevailing wind conditions. Significant attenuations in wave heights were identified in the intermediate and shallow waters, with the highest attenuation occurred in the central Jeddah coast. [ABSTRACT FROM AUTHOR]

The sponge Chalinula saudensis, which occurs along the Jeddah coast, has only recently been isolated and identified. In this study, the total crude organic matter of the sponge was extracted by solvents. The total crude extract was further separated by partitioning it with hexane and water, then with water and chloroform, and finally with water and t-butanol. The chloroform layer was subjected to separation by preparative layer chromatography on silica. One fraction contained four long-chain fatty acid esters, C28H56O2, C30H60O2, C32H62O2 and C36H70 O2. The second ester, C30H60O2, has been identified in the fire corals Millepora dichotoma and Millepora platyphylla. The others have not previously been reported from marine organisms; however similar long-chain esters with different long aliphatic chains and with different molecular weights have been identified from other marine organisms. These compounds are normally waxy and their presence in Chalinula saudensis plays a vital role in the biosynthetic pathways. They also act as insulators against seasonal variations.A esponja Chalinula saudensis ocorre ao longo da costa de Jeddah, Arabia Saudita, mas apenas recentemente foi isolada e identificada. No presente estudo a matéria orgânica total da esponja foi extraída por solventes e o extrato foi separado por partição sucessiva através do emprego de hexano e água, clorofórmio e água e finalmente t-butanol e água. A camada contendo clorofórmio foi então separada por cromatografia em sílica. Os resultados mostraram a presença de ésteres de quatro ácidos graxos de cadeira longa (C28H56O2, C30H60O2, C32H62O2 e C36H70O2), sendo que o segundo deles foi também identificado nos corais Millepora dichotoma e Millepora platyphylla. Não se tem evidência da presença dos demais compostos em outros organismos marinhos, embora haja relatos para ésteres semelhantes de cadeia longa, mas contendo diferentes cadeias alifáticas e diferentes pesos moleculares. Os compostos isolados em C. saudensis são geralmente ceras e sua presença na esponja tem importância não só nas rotas de biosíntese, mas servem como isolantes nas variações sazonais adversas.

Mycosporine-like amino acids (MAAs) were studied in stony coral species (Fungiidae) along the Eastern coast of the Red Sea. Six species - Fungia scutaria, F. danai, F. corona, F. repanda, Ctenactis echinata and Lithophyllor lobata - were examined for MAAs at water depths of 5, 10, 15 and 20 m. Protein and chlorophyll were also determined and showed higher contents in winter than in summer. Generally, the total content of MAAs in summer was found to be approximately three times greater than in winter. Overall, concentrations of MAAs were greatest at a depth of 5 m. Porphyra-334 was the most abundant MAA in F. Scutaria and F. Danai, whereas asterina-330 was either not detectable (e.g. L. lobata) or present in low concentrations (e.g. F. danai, F. repanda and C. echinata). Shinorine was not detected in F. danai or L. lobata. Both C. echinata and L. Lobata had the lowest concentrations of MAAs, presumably because of their large calcareous skeletons. The variation in MAA concentrations among seasons and water depths is probably due to a number of factors, including the intensity of solar radiation, turbidity and phylogenetic variation.

Aliphatic hydrocarbons including resolved aliphatics (C11-C30), isoprenoids (phytane and pristane) and unresolved complex mixture, as well as total aromatic hydrocarbons were analyzed in 25 surface sediment samples represented five sites along Jeddah coast, Red Sea. The descending order of total petroleum hydrocarbons in the different sites along the coast was found as following: Al-Arbaeen Lagoon (site 2) 481 ppm > Al-Shabab lagoon (site 3) 410 ppm > Southern Corniche (site 1) 205.3 ppm > Northern Corniche (site 4) 172.7 ppm > Sharm Obhur (site 5) 23.6 ppm. The concentrations of total aliphatic hydrocarbons were ranged between 2.18 and 492 ppm dry weights, while the range for the total poly aromatic hydrocarbons was from 2.67 to 160.6 ppm dry weight. The highest concentrations for hydrocarbons were recorded at site 2 (Al-Arbaeen lagoon, station 8). The indices used to evaluate the probable origin of hydrocarbons indicated petroleum origin with high degradation process in most stations as well as fresh oil inputs in few stations at sites 1 and 4. The levels of total aromatic hydrocarbons for 80% of studied stations were exceeding effects range- median value (ERM) for the sediment quality guideline (SQG). [ABSTRACT FROM AUTHOR]

Thirty sediment samples were collected from six sites in Jeddah coast, Red Sea to assess the concentration levels of polychlorinated biphenyls (PCBs). Concentrations of ∑19 PCBs at the study area were ranged from 0.58 to 15.63 ng/g dry weight. The highest concentrations were recorded in the semi closed lagoons Al-Shabab and Al-Arbaeen (sites 4 and 5) which are highly influenced by sewage dumping. Textural classification of the sediments was found to be highly correlated with PCBs concentrations. PCB congener # 87 (penta-CB) showed the highest concentration among the 19 PCBs congeners. The descending order of different PCBs congeners was: penta-CB > tetra-CB > hexa-CB > mono-CB > tri-CB > hepta-CB > nona-CB. The medium PCBs congeners penta-, tetra- and hexa-CBs represented the major components at all sites. Aerobic and anaerobic environmental conditions change the homologue percentage in all stations. The contamination levels of PCBs in all sites were found to be below the two common sediment quality guidelines; the effects range-low value (ERL) and the threshold effects level (TEL). [ABSTRACT FROM AUTHOR]

Copyright of Arab Gulf Journal of Scientific Research is the property of Arabian Gulf University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Oceanography is the property of Instituto Oceanografico da Universidade de Sao Paulo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Al-Salam Lagoon is one of the recreational sites along the Jeddah coast, showing the environmental impacts of urbanization along the coast. A sediment core (220 cm) was collected from the intertidal zone to evaluate the heavy metals (Fe, Mn, Cr, Ni, Cu, Zn, and Pb) and geochemical indices (contamination factor, geo-accumulation index, and pollution load index). In the organ-ic-rich muddy sediments (0–100 cm), there is a high metals content and a pollution load index of ~3, indicting anthropogenic impacts with high Cu contamination (CF:12) and moderate Fe, Mn, Cr, Ni, Zn, and Pb contamination (CF: <3). The organic matter and heavy metals washed through surface run-off from the land and deposited as urban waste. Down the core, consistent metals concentration, CF, and Igeo trends indicate a common pollutant source and pollution load variations over time. In the sediment section (70–40 cm), a high organic matter, metal concentration, CF, Igeo, and PLI value (≥5) suggest an uncontrolled pollution load. The decreased and stable trends of environmental indicators toward surface sediments suggest measures taken to control the pollution along the Jeddah coast. Below 110 cm, the carbonate-rich sediments have low organic matter and metals, showing an unpolluted depositional environment. The negative geo-accumulation index implies a geogenic source and indicates no anthropogenic impacts as inferred from low (~1.0) CF and PLI. [ABSTRACT FROM AUTHOR]