مجلة جامعة الملك عبدالعزيز: علوم البحار

Photophysiology Photophysiology Response Of Montipora Sp. To High Temperature and High Nitrate Stress

Tengku Fara Tengku — 2025-01-05

Coral reef health has declined significantly around the world as a result of anthropogenic activities and natural environment changes, such sewage pollution and climate change due to global warming. These significant threats can interrupt coral’s fluorescence yield and also modify the zooxanthellae performance, which can lead to bleaching events if prolonged stress. Nowadays, other than using zooxanthellae density to determine coral’s health, numerous study starts to focus more on observing the effective quantum yield, Y(II) of corals by using Pulse Amplitude (PAM) fluorometer, as it is an effective and non-lethal way in determining coral’s health. In this study, there are two objectives to be achieved which are i) To measure the effective quantum yield of Montipora sp. before and after nitrate and temperature stress and ii) To calculate the zooxanthellae density of Montipora sp. after nitrate and temperature stress. Montipora sp. that was exposed to high nitrate (HN), high temperature (HT) and high nitrate with high temperature (HNHT) treatment exhibited the decrement of their Y(II) reading and zooxanthellae density after 48 hours exposure. Major decrease of Y(II) resulted from the HN treatment while major drop of zooxanthellae is caused by HT treatment. For future studies, longer term experiment duration, various coral species and molecular studies should be done to understand the photoinhibition process and its effect to the coral body system.

Growth rate, Lipid and Fatty acids content in some Marine and Freshwater diatoms

Abdulfattah Elfituri — 2025-01-05

Diatoms are photosynthetic organisms that can produce lipids in large amounts within a short time. Their biomass can be processed into biofuels and other valuable commercial products. In this research, six diatom species were isolated from Malaysian water (seawater and freshwater) and grown under the same conditions to observe differences in their lipids and fatty acids composition. The results showed significant differences in total lipid contents between freshwater and marine species. Where Sellaphora pupula, Nitzschia palea, and Craticula cuspidate (Freshwater species) had a relatively constant percentage of lipid (13 to 16.1 % of dw) while Nitzschia sp, Chetoceros calcitrans, and Nitzschia sigma (marine species) had high lipid contents (>18 %). Total fatty acid content slightly varied between marine and freshwater diatoms (43.5 to 60.5). Palmitoleic acid-C16:1 (29.9 to 39.5% of TFA) and Palmitic acid-C16:0 (15.6 to 33.2% of TFA) was predominant in most of the six diatoms studied. In addition, ω-3 and ω-6 PUFA showed a high percentage in some marine and freshwater species (Nitzschia sp and C. cuspidata), which suggested both species had a good quality of polyunsaturated fatty acid and could be used as food sources in aquaculture or in other useful applications.

تقييم تنوع الطيور الخواضة وطيور الشاطئ في بحيرات عدن - عدن / اليمن

Abeer Yousuf Qardash — 2025-01-05

تهدف هذه الدراسة إلى تقييم تنوع الطيور الخواضة وطيور الشاطئ في بحيرات عدن من أكتوبر 2021 إلى ديسمبر 2022. تم تسجيل أربعة وخمسين نوعًا تنتمي إلى سبع عائلات لطيور الشاطئ وخمس عائلات من الطيور الخواضة في منطقة الدراسة. وسجلت أعلى وفرة نسبية 14.78% في يونيو 2022 ، بينما سجلت أدنى نسبة% 3.03 في أبريل 2022. مؤشر تنوع Simpson 0.95 ، في حين كان مؤشر Shannon-Weiner 3.25. بلغ مؤشر الثراء 5.432 ، في حين بلغ مؤشر التكافؤ 0.862. سجل مؤشر الهيمنة قيمة عالية في نوفمبر 2021 ويوليو 2022 وأغسطس 2022 وسبتمبر 2022 ونوفمبر 2022. وكان تجمع الطيور الخواضة وطيور الشاطئ في بحيرات عدن معتدلاً ، بينما أظهر تجمعًا مضطربًا وشبه متوازن من حيث الثراء والتساوي على التوالي.

The The first record for the shore crab, Cyclograpsus aff. integer (Cyclograpsinae: Varunidae: Grapsoidea) from the Egyptian coasts of the Red Sea

Awaad El-Sayed — 2025-01-05

تشير النتائج الحالية إلى تسجيل نوع سيكلوجرابسس انتيجر(Cyclograpsus aff. integer Cyclograpsinae: Varunidae: Grapsoidea) من عائلة فارونيدي التي تتبع فوق عائلة الجرابسويديا من السرطانات الأصيلة بالشواطيء المصرية قاطبة ومن البحر الأحمر عامة، ويعتبر هذا النوع من الأنواع صغيرة الحجم التي تقطن المناطق الرملية المختلطة بفتات الصخور والرمال والمواد العضوية المتحللة حول تجمعات نبات المانجروف وفي مصبات الأودية حيث تبني أنفاقا للمعيشة بتلك البيئات. ولقد أوضحت الصفات التشخيصية لهذا النوع والتي تميزه عن غيره من الأنواع قريبة الشبه وجود اختلاف في بعض الصفات التصنيفية للعينات الحالية عن مثيلاتها من نفس النوع المسجل سابقا من مناطق انتشاره بالمحيطات الهندي والهادي والأطلسي مما يؤدي هذا التسجيل إلى احتمالية كونه نوعا جديدا وزيادة فونة سرطانات الجرابسويديا بالبحر الأحمر إلى20 نوعا حسب التسجيلات السابقة, وإلى 13نوعا بالشواطيء المصرية، تمثل أكثر من 65% من إجمالي فونة سرطانات الجرابسويديا بالبحر الأحمر.

First Descriptions of the ocean-collected first Crabs of Etisus sp. (Crustacea: Brachyura: Portunidae) from the Saudi Arabian Red Sea

ندي ناقور — 2025-01-05

No first crab of the genus Etisus has been described yet. Thirty five megalops of an Etisus sp. were collected from Obhur Creek, Jeddah, Saudi Arabia and reared in the laboratory upto first crab stage. These first crabs were identified using molecular barcode methods and morphologically described herein and compared with those of the two species of Xanthoidean crabs, Eurytium limnosum and Leptodius exaratus. Apart fromsome minor variations, three characters differentiate the first crabs of the present study with those of the other two species: presence of several minute spines on the basal segment of the peduncle of antennule, presence of crista dentate in the endopod of third maxilliped and serrated lateral margins of third abdominal segment.

Seaweed: A Multifaceted Marvel Driving Global Sustainability and Environmental Health

Muhammad Abdul Waheed — 2025-01-05

This article explores the potential of seaweed as a sustainable resource for the environment. Seaweed has been traditionally consumed as food by coastal communities and used as animal feed, but it also has applications in other industries. Seaweed can capture carbon and can also provide a habitat for fish species. Seaweed reduces the use of antibiotics and boosts the immune system. Several types of seaweed are often utilized in medications in their raw form. It is an important biorefinery feedstock it is used to produce a variety of materials like cosmetic products, polymeric substances (Protein, cellulose), agrifood, and food supplements with several health advantages. seaweed has the best nutritional profile and higher polysaccharides % making it the best choice to use as a fuel resource.Seaweed farming is a simple eco-friendly approach to sustainable development and provides massive biomass for the production of food and related products in the food, pharmaceutical, cosmetic, and agro-industries. Seaweed production significantly contributes to catalyzing sustainable aquaculture by providing food to aquaculture species. All three types of red, brown, and green seaweeds have been extensively used in various wastewater treatment processes as they can store high concentrations of nitrogen in their tissues. Seaweed is an enriched source of bioactive compounds that affect the rumen microbiome, enhance rumen digestibility, and check the levels of CH₄ production in livestock. Seaweeds also act as bioindicators and bioremediator of eutrophied areas. Moreover, seaweeds are important bio-resource of renewable energy.

Sediment Characteristics Study at Sharm Obhur, the Red Sea using Multibeam Backscatter

Hatem Hashem — 2025-01-05

Sharm Obhur, situated approximately 35 km north of Jeddah City along the Red Sea coast, is a prominent recreational area with diverse benthic habitats. Accurate mapping of seabed sediments is critical for characterizing marine ecosystems and elucidating benthic habitat distribution in this region. This study underscores the importance of assessing sediment distribution patterns in Sharm Obhur, particularly due to the prevalence of recreational activities and navigational traffic. This research investigates sediment dynamics in Sharm Obhur, a coastal creek near Jeddah, utilizing Multibeam Echo Sounder (MBES) backscatter data and grab sample analyses. The study focuses on understanding sediment distribution patterns and their implications for coastal management. MBES technology provides high-resolution data on seafloor composition and roughness, essential for assessing sediment types and bedforms. Through spatial alignment of MBES data with ground truth sediment samples, we analyze sediment characteristics and validate findings. Results indicate predominant sand presence with detectable mud in deeper channels and northern anthropogenically impacted areas. Gravel deposits correlate with coral formations near the creek edges. Tidal influence is evident, with increased sand presence at the creek entrance. The study demonstrates MBES backscatter's efficacy in mapping sediment distributions and seabed characteristics, benefiting marine science and coastal management. This research enhances knowledge of sediment transport processes, facilitating informed decision-making for sustainable coastal development and conservation efforts.

Benthic Foraminiferal Distribution in the Red Sea coastal sediments, Shalateen Area, Egypt: Environmental Biomonitoring Implications

Islam Fares — 2025-01-05

The Red Sea coast is overcrowded by many international and local harbors, particularly Shalateen harbor, that imposes environmental threats on the marine biota. The Shalateen ecosystem is assessed using benthic foraminifera, a sensitive proxy to environmental change. This study investigated the relationship between ecological parameters and benthic foraminifera distribution in the Shalateen site, a coastal area on the Red Sea facing increasing environmental deterioration. A total of 17 stations were sampled, and their benthic foraminiferal contents were analyzed. The findings revealed enriched benthic foraminiferal assemblages, dominated by Miliolida and Rotaliida, where counted morphological deformities in foraminiferal tests were observed and counted. Siamese twins, wrong direction of coiling, and aberrant chambers are the depicted test abnormalities. They are higher in the miliolids than rotaliids. A statistical analysis identified two distinct foraminiferal assemblages; group 1 is associated with shallow, high-energy habitats with elevated salinity and carbonate content, while group 2 occupies deeper waters with higher organic matter and finer sediments. The environmental-based foraminiferal indices (FAI, FI, FMI and AEI) highlighted that the stations in the nearby harbor have higher environmental impacts than the offshore stations. These findings provide crucial baseline data for future environmental management and conservation efforts in this vulnerable ecosystem.