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In the present study, 18 polychlorinated biphenyl (PCB) compounds were measured in marine sediments collected from 49 offshore stations in the Persian Gulf and the Gulf of Oman in 2019. After the last oceanographic cruise in 2006, no study has been performed on the offshore sediments of this region, and this is the first study on the PCBs in this area. The total amount of PCB compounds in the sediment samples ranged from 74.38 ng kg−1 (near Abu Musa Island) to 1212.98 ng kg−1 (near Siri and Kish Island). The maximum and minimum values of the individual detected PCB compounds were 175.88 ng kg−1 (PCB52) and 2.09 ng kg−1 (PCB156), respectively. The levels of total PCBs detected in sediments were lower than the Canadian interim sediment quality guideline value of 21500 ng kg−1 for marine sediments. The sedimentary mass inventories for Σ18PCBs were 0.6 and 0.2 mt for the Persian Gulf and Gulf of Oman, respectively. [ABSTRACT FROM AUTHOR]

Global warming may alter the dynamics of infectious diseases by affecting important steps in the transmission of pathogens and parasites. In trematode parasites, the emergence of cercarial stages from their hosts is temperature-dependent, being highest around a thermal optimum. If environmental temperatures exceed this optimum as a consequence of global warming, this may affect cercarial transmission. However, our knowledge of cercarial emergence patterns of species from high temperature environments is currently very limited. Here, we investigated the effect of temperature on the emergence of two common trematode species from an abundant mud snail Pirenella cingulata in the Persian Gulf, the warmest sea on Earth. Infected snails were incubated in the laboratory at 6 temperatures from 10 to 40 °C for 3 days. We found an optimal temperature for cercarial emergence of 32.0 °C and 33.5 °C for Acanthotrema tridactyla and Cyathocotylidae gen. sp., respectively, which are the warmest recorded thermal optima for any aquatic trematode species. Emergence of both species dropped at 40 °C, suggesting upper thermal limits to emergence. Overall, Persian Gulf trematodes may be among the most heat-tolerant marine trematode species, indicating a potential for dispersing to regions that will continue to warm in the future. [ABSTRACT FROM AUTHOR]

Avian schistosomes, comprise a diverse and widespread group of trematodes known for their surprising ability to switch into new hosts and habitats. Despite the considerable research attention on avian schistosomes as causatives of the human cercarial dermatitis, less it is known about the diversity, geographical range and host associations of the marine representatives. Our molecular analyses inferred from cox1 and 28S DNA sequence data revealed presence of two schistosome species, Ornithobilharzia canaliculata (Rudolphi, 1819) Odhner, 1912 and a putative new species of Austrobilharzia Johnston, 1917. Molecular elucidation of the life-cycle of O. canaliculata was achieved for the first time via matching novel and published sequence data from adult and larval stages. This is the first record of Ornithobilharzia from the Persian Gulf and globally the first record of this genus in a potamidid snail host. Our study provides: (i) new host and distribution records for major etiological agents of cercarial dermatitis and contributes important information on host-parasite relationships; (ii) highlights the importance of the molecular systematics in the assessment of schistosome diversity; and (iii) calls for further surveys to reach a better understanding of the schistosome diversity and patterns of relationships among them, host associations, transmission strategies and distribution coverage. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the content of omega-3 fatty acids in Persian Gulf fishes. The fishes were collected from Persian Gulf and the content of fatty acids in the head, muscle, and liver of fishes were determined. Quantitative analysis of fatty acids was performed by gas chromatography (GC) and methylmyristate was used as the reference material. GC and mass spectrometer (GC- mass) was applied for qualitative analysis and cod liver oil with all of omega-3 fatty acids was used as standard. Ghezel ala, Zamin kan-e-dom navari and Sorkhu mahi had maximum levels of omega-3 in total body. Halva Sefid, Gish-e-deraz baleh and Shamshiri were poor sources of omega-3. The liver of fish had the most content of omega-3 fatty acids followed by muscle and head, respectively. [ABSTRACT FROM AUTHOR]

Beach and delta areas are dynamic physical features with changes occurring at many spatial and temporal scales due to both general and catastrophic events. Geomorphic changes such as temporal and periodic changes in riverbeds and coasts are common events in all deltaic areas. The Hendijan river basin is located in the southwest of Iran, close to the city of the Hendijan and many villages and rural settlements. Changes in various geomorphic features, such as riverbed and shoreline migration, Sebkhas, alluvial terraces, meanders and old, dry rivers over 48 years of time, were detected and identified using Landsat TM and ETM satellite data and topographic maps. Simple bands subtraction, principal component analysis (PCA) and fuzzy logic were used to identify regions that have undergone land cover change. Results of this study show that the Hendijan River channel has migrated several times over the last 48 years. Several meanders and ox-bow lakes remain as a result of migration. The shoreline has migrated over 4 km into the Persian Gulf. The resulting maps can be used in an integrated coastal zone information system as it has been proposed for the Heddijan delta. [ABSTRACT FROM AUTHOR]

This paper presents the paleocurrent evolution of the Persian Gulf deep water (PGDW) during the last 5000 years using faunal (foraminiferal assemblage) and non-faunal (magnetic susceptibility, sediment grain size, number of coarse relict particles and physicochemical characteristics) indicators from a 133 cm long core retrieved from the Strait of Hormoz (SH). Our results suggest that the precession-related insolation change and solar variability induced long-term and short-term sea surface temperature (SST) rise and fall resulted in variation of PGDW outflow strength. Two periods of decreasing SST (5000–4300 and 2000–1450 cal yr BP), accompanied by wetter conditions in the Middle East, are related to the reduction of the PGDW current velocity. A combination of high sedimentation rate (0.72 mm yr−1, due to high terrigenous input) with a relatively low bottom flow energy cause the settling of finer sediments providing a favourable environment for the expansion of benthic foraminifera (dominated by infaunal taxa). On the contrary, the PGDW current velocity strengthens in the periods of SST increase (4300–2000 and 1450 cal yr BP to present) with decreasing sedimentation rate (0.15–0.34 mm yr−1, due to low river discharge). During both periods of high-velocity bottom currents, the benthic foraminifera accumulation rate decreases. However, as the PGDW brings a relatively high amount of dissolved oxygen (3.25 mg/l in summer and 4.79 mg/l in winter) and phytodetritus particles, compared to the surrounding water, some particular foraminifera (especially robust suspension feeder epifaunal taxa) evolved. SST increase, intensified by anthropically caused global warming, may lead to PGDW intensification in the future. • Since the mid-Holocene, PGDW intensity has been under influence of the continental climate of SW Asia and the Arabian Sea SST. • SST intensification (4500 to 3000 and 1400 cal yr BP to present), causes increasing bottom current energy of the Strait of Hormoz and decreasing river discharges. • Although high energy bottom currents provide a hostile environment for the benthic fauna, it brings high DO content bottom waters. [ABSTRACT FROM AUTHOR]

In this study, the amount of heavy metals such as Ni, Cd, Pb and Cu and some physiochemical factors including pH, temperature and total organic carbon (TOC) in the ballast water of the ships entering the Bushehr Port were measured for two years (cold and hot seasons) before and after the ballast water convention was enforced. The mean concentrations of Ni, Cd, Pb and Cu, before and after implementation of the convention were 46.55, 3.93, 5.36, 58.83 and 26.41, 2.12, 2.59, 23.54 ppb. It became clear that the concentrations of heavy metals after the implementation of the convention was lower in comparison and there was a significant difference (p <.05). It seems that continuous monitoring of the quality of the ballast water and determination of locations free of pollution and contamination in the Persian Gulf are necessary for ships that intend to exchange their ballast water in this Gulf. • We investigate the BWMC in Persian Gulf and in Iran Bushehr port along Persian Gulf. • We use the valid standard method , MEPC 173 (Wu et al., 2019) and we investigate different origin ports to achieve useful resultsWe used 32 ships after and before implementation of this convention. • Results show that the BWMC is important in Persian Gulf and continuous monitoring of the quality of the ballast water for ships entering Bushehr port is necessary. • This study includes valuable information that was first conducted in the Persian Gulf area and investigated the effectiveness of the ballast water convention in this area. • Monitoring of ships crossing between Persian Gulf ports must be done more carefully, and unfortunately there is no effective convention in IMO for this area. [ABSTRACT FROM AUTHOR]

While the impact of ocean warming on single species is well described, the impact on marine biofouling communities is not well understood. Effluents of power plants have higher temperatures and can be used as natural large-scale test sites to investigate warming effects on marine ecosystems. In the present study, we evaluated the impact of elevated temperatures in the vicinity of a power plant on macro-biofouling communities in the northern coast of the Persian Gulf. The impact site was on average 2 °C warmer than the control site. Our results demonstrate a significantly different structure and composition of biofouling communities between control and impact sites. Warming led to a 1.5-fold increase in the mean coverage of biofouling communities and slightly decreased functional and species richness. Our results indicated that future warming will likely increase biofouling pressure, while decreasing diversity of communities, particularly in habitats where organisms exist at their upper tolerance limits of temperature. • Structure and composition of biofouling communities were different between control and impact sites. • Warming led to a 1.5-fold increase in the mean coverage of biofouling communities. • Warming slightly decreased functional and species richness of biofouling communities. • Future ocean warming will likely increase biofouling pressure in the northern Persian Gulf. [ABSTRACT FROM AUTHOR]

The main objective of this work is the manipulation of hydrophilic materials in support, intermediate and selective layer to synthesize a novel nano-tubular ceramic membrane for treatment of oily wastewater. First, porous mullite-alumina-zeolite composite membranes were prepared by an extrusion method. Changes in porosity, pore size, shrinkage, and mechanical strength of the support membranes were investigated as function of percentage composition and sintering temperature in order to obtain the optimal conditions. According to the results, the most favorable condition set was determined to be a support membrane with a weight percent of 50, 30, and 20 for mullite, alumina, and zeolite, respectively, and a porosity of 38%, a pore size of 0.39 µm, and a shrinkage of 10.2% sintered at 1250 °C and with good mechanical properties at 24.6 MPa. The cross-flow filtration technique was employed to coat the natural zeolite on the inner surface of the support membrane to achieve a narrower pore size distribution. Finally, a thick layer of nano-SiO 2 was coated on the membrane by utilizing the dip-coating method to develop a hydrophilic membrane while avoiding defects. Moreover, scanning electron microscopic (SEM) analysis of the SiO 2 membranes showed that the natural zeolite and nano-SiO 2 layer is homogeneous and demonstrates high adhesion to the support membrane. Besides, the result of COD rejection showed that the SiO 2 membranes have an undeniable capability in rejection of oil droplets with a reasonable permeation flux. Therefore, the obtained membranes are highly promising for practical applications and environmental remediation in sensitive Persian Gulf zone. [Display omitted] • Fabrication of novel nano-SiO 2 tubular ceramic membrane utilizing hydrophilic materials. • Inexpensive raw materials and low sintering temperatures in fabricating of low-cost ceramic membrane. • Porosity, pore size, shrinkage, and mechanical properties at various sintering temperatures were investigate. • SEM showed that the top layer is homogeneous and demonstrates high adhesion to the support membrane. • The treatment of wastewater with high oil rejection (99.2%) and permeation flux (690 L/m2.h.bar). [ABSTRACT FROM AUTHOR]

In this work, a mathematical model was made for a Hybrid Membrane-Based Air Conditioning System to evaluate the performance of the proposed system. The hybrid system consisted of a cross-flow membrane air dehumidifier unit and a membrane contactor unit as humidifier. The model was further validated using simulation and experimental data from the literature. The effects of the parameters such as dehumidifier stage cut, pressure ratio and humidifier geometry were studied. Then, the performance of the system was evaluated in terms of sensible, latent and total cooling capacity and latent heat ratio. The hybrid system produced fresh air with minimum temperature of 13.5 °C and humidity ratio below 12 g/kg providing a thermal comfort condition for human activities. Also, the results showed that the maximum total cooling capacity was 3.3 kW when the dehumidifier pressure ratio was 20, and LHR of the hybrid system was in the range 0.35–0.63. The results also showed that the membrane air-conditioner had a low energy consumption, saving energy up to 66% in comparison to the conventional air-conditioners. The proposed membrane air-conditioner is capable to operate in a wide range of humidity in the Persian Gulf region, while maintaining the thermal comfort conditions. Image 1 • A novel membrane hybrid air-conditioning system was designed. • The proposed air conditioner is capable to operate in a wide range of humidity. • The proposed air conditioner can achieve the thermal comfort conditions. • The proposed system is superior to conventional ACs in terms of energy consumption. [ABSTRACT FROM AUTHOR]