جستجوی مقالات مرتبط با کلیدواژه « Persian Gulf » در نشریات گروه « زیست شناسی »

Due to global warming and climate changes, the water level of the Persian Gulf has increased, and these changes have led to an increase in sedimentation level and retreat of mangroves in the Hara protected area towards land. In the present study, the trend of changes in the water level of the Persian Gulf from 2000-2023 and also the extent of mangrove forests in the Hara protected area in Hormozgan province were investigated. In this study, the fluctuation trend of Persian Gulf water using L5-TM images for the year 2000 and L8 and OLI-TIRS images for the year 2023 in the Google Earth Engine (GEE) web system. It was monitored and analyzed. In this way, the water level monitoring maps of the Persian Gulf were extracted based on the normalized difference of water zones index (NDWI) and classified into two classes, blue and non-blue. In the following, using the Kolmogorov Smirnov statistical tests and Spearman's non-parametric correlation coefficient, the relationship between the water level changes in the Persian Gulf and the extent of mangroves in the Mangrove Protected Area was investigated. According to the results, the fluctuations of the water in the Persian Gulf from 2000 to 2023 had an increasing trend, so that the sea level in 2000 was equal to 5 mm and in 2023 these changes reached 90 mm. Also, the results of the extent changes of mangrove forests in the Hara protected area indicate that this habitat has decreased in 2023 compared to 2000. The analysis of the relationship between changes in the water level of the Persian Gulf and the extent of mangroves in this area reveals that a high correlation can be seen between these two variables during the studied years. This means that there is a direct relationship between the increase in water level changes in the Persian Gulf and the decrease in the mangrove forests of the Hara Protected Area. The continuous increase in sea level and its consequences can be one of the most important reasons for the reduction of mangrove habitats in the future. Considering the importance of mangrove habitats in the Hara protected area as a provider of a wide range of ecosystem services, as well as high biodiversity, management solutions should be considered to control and reduce the consequences and risks caused by the fluctuations of the sea water in the Persian Gulf.

Background and Theoretical Foundations: 

Blue economy, which has been become a principal part of political, economic and scientific diplomacy of various countries, focuses on economic growth based on sustainable exploitation and protection of marine resources. Marine aquatics production (capture fisheries and aquaculture) is one of the main sections of development of blue economy.  Iran (Islamic Republic of), with 1800 km borderline with the Persian Gulf, is the largest fisheries state in the region and has a high capacity in terms of blue economy.

A qualitative study was used to gather data through a literature review on blue economy. Forty-three scientific papers were analyzed and their primary concepts were illustrated by a word cloud graph.  

Analyses of the contents indicated that blue justice is a top ten concept to blue growth. As a consequence of overfishing and climate change, fish stocks of Iranian coastal waters of the Persian Gulf have mostly been depleted in the past few years. It has led to increasing the vulnerability of small-scale fishing (SSF) communities than before. Therefore, it should be paid a specific attention to these communities in processes of policy making to development of blue economy.

Showing the limitations of blue justice implementation in the region, the present paper demonstrated that blue economy will not developed without considering justice and its implementation is a task for government.

Stock Assessment of marine aquatic is essential for modern management and sustainable conservation of fishery species, which has been rapidly developed by improving the ability of computer simulation with stock assessment methods, and for sustainable management and exploitation of fish stocks, knowledge of parameters such as age, growth and reproductive biology fishes are essential, and the output information can be used to plan and develop fisheries programs in the future. Fishing management has a wide range of goals, which include identification of aquatic population, assessment of stocks, use and development of fishing tools in order to efficiently exploit the stock and ensure the benefits of fishing users by providing a sustainable harvest deal. Stock assessment models are one of the strategies used to preserve fishery species.

In this study, some biological characteristics of greenback mullet fish were investigated during six months of 2023 in the coastal waters of Bandar Abbas. For this purpose, after sampling, 120 of the fishes caught were transferred to the laboratory for biometry of length and weight parameters and were subjected to biometrics. After morphometric analysis of greenback mullet samples, fish growth parameters such as Growth performance index, condition index, von Bertalaneffy growth function (VBGF), mortality coefficients and exploitation ratio were calculated using FiSAT software processing.

The results of the study showed that the average total length and weight of greenback mullet fish were 11.06 cm and 21.90 gr, respectively. In this fish, the relationship between total length and total weight was obtained as W=0.1886TL1.9226. The parameter of condition index in the entire sampling period had strong fluctuations in the first half of the sampling period and did not change significantly in the second half and was almost the same. Among the parameters calculated, we can mention the growth function of von Bertalaneffy growth function and factors such as forked length, growth coefficient and t0 were calculated as 20 cm, 1.1 and -0.1 per year, respectively. Total and natural mortality rates were estimated as 2.56 and 2.07 per year for the samples, respectively.

Stock assessment is the process of collecting, analyzing and reporting fish population information to determine changes in the abundance of fishery stocks in response to fishing and to predict the future trends of stock abundance as much as possible. In this study, the results showed that greenback mullet fish in the coastal waters of Bandar Abbas are young fish. For both males and females, the growth index is the highest, and overfishing, especially during the spawning seasons, has messed up the regeneration of the young population, Therefore, not having proper management in fishing can damage this valuable stock in the coastal waters of Bandar Abbas. Therefore, it is suggested that this study be re-evaluated in a longer period of time and with a larger number of samples so that the results can be proven with more certainty.

The study of food composition and feeding ecology of fishes living in the intertidal zone are essential in understanding the energetic connectivity between terrestrial and aquatic ecosystems. The mudskipper Periophthalmus waltoni is an amphibious fish in the intertidal zone. The aim of this research was to discern how spatial and temporal factors influence the species' diet. A total of 319 individuals were collected across two estuaries in Hormozgan province (184 in Bandar Abbas and 135 in Bandar Khamir) during November 2018 to April 2018. The results revealed that P. waltoni primarily follows a carnivorous diet, as indicated by their relative gut length (RLG) and diet composition. The individuals measured 9.2–11.8 cm in total length and 8.1–15.8 g in weight. Analysis of stomach contents identified three main preys: Uca, Gastropoda, and Coleoptera, with Bandar Abbas and Bandar Khamir showing a prevalence of crab (79.31%) and Gastropod (54.16%), respectively. The mudskipper's feeding strategy, as per Castello, appeared general in Bandar Abbas and specific in Bandar Khamir. The highest frequency index of prey occurrence for specimens in Bandar Abbas for crab prey was calculated at 68.31%, while in Bandar Khamir, it was determined as 42.52% for gastropods. Stomach emptiness index values of 21.49% and 13.86% suggest P. waltoni is a voracious feeder.

Coastal areas represent the most vulnerable regions of the ocean. Thus, the identification and estimation of sedimentation rates in the sensitive coastal habitats of Qeshm and Lark islands were conducted during 2022-2023. The diving team identified three habitats consisting of natural structures in the north of Larak Island, characterized by the predominance of Acropora sp., and one habitat featuring flora and fauna originating from human-made structures (Doha Qeshm Jetty). These habitats, resembling those on Larak Island but on a smaller scale, were mapped using ArcGIS software 10.1. Three sediment traps were placed at 500-meter intervals in each station to cover each habitat comprehensively. The minimum and maximum sedimentation rates were measured at Larak Islands (St3) with 28 and Doha Qeshm Jetty with 196 (g/m2/day), respectively. Additionally, the minimum and maximum concentrations of suspended substances in the water column, ranging from 9.44 to 21.31 (mg/lit), were observed at these two stations during autumn. The freshness of Acropora sp. served as an indicator in all four habitats, potentially reflecting either the negligible impact of sedimentation rates on communities or the resilience of these communities to sedimentation during the study period

The study aimed to assess temporal and spatial variations in the population of polychaetes, a significant invertebrate group in deep-sea ecosystems, across the northern waters of the Persian Gulf and the Oman Sea. Sampling occurred from fall 2018 to winter 2020, covering regions in Hormozgan, Bushehr, Sistan and Baluchestan, and Khuzestan. A total of 115 stations were surveyed, utilizing 0.1 square meters and a 500 μm sieve (repeated thrice) to collect bed sediments within the depth range of 12 to 90 meters. Within this study, 35 species/genus of polychaetes were identified in the waters of the Persian Gulf and the Oman Sea. Notably, Flabelligra sp., Manayunkia aestuarina, and Glycinde sp. exhibited the highest abundance, with Flabelligra sp. and M. aestuarina serving as indicator species in both regions. The provinces of Sistan and Baluchestan and Bushehr displayed the highest Shannon diversity and species richness, recording 3.592 and 6.998, respectively. Comparing these findings with prior reports revealed a reduction in the diversity of identified polychaete species in the Persian Gulf. This decline could stem from various factors such as habitat damage due to fishing equipment, and the incidence of contaminants. Continual research and database establishment for time series analysis could significantly aid researchers, authorities, and environmental advocates in comprehending the health status of the Persian Gulf and the Oman Sea. Such efforts would facilitate environmental monitoring and pollution prevention measures, contributing to the preservation of these ecosystems

The study delved into bacteriocins, peptides with antibacterial properties, originating from select lactic acid bacteria. Isolating 18 such bacteria from Liza klunzingeri's intestine, their potential in bacteriocin production against food pathogens was assessed. Crude bacteriocins from 7 isolates exhibited the ability to inhibit food pathogens via an agar spot test. Notably, bacteriocins derived from LK5 and LK12 isolates displayed a broader inhibitory spectrum against the pathogens under study. Further analysis revealed that the studied bacteriocins were susceptible to proteolytic enzymes, leading to complete degradation. However, these bacteriocins retained their antibacterial potency when subjected to diverse detergents, pH variations, and temperature fluctuations. Genetic analysis via the 16S rRNA gene identified LK5 and LK12 as strains of Lactobacillus plantarum, with similarity percentages of 98.55% and 99.46%, respectively. The findings highlight L. Klunzingeri's intestinal bacterial flora as a promising source for isolating bacteriocin-producing bacteria. Specifically, bacteriocins derived from L. Plantarum LK5 and L. Plantarum LK12 showcase potential as biological preservatives within the food industry, warranting further exploration.

The Persian Gulf and the Oman Sea are habitats for a variety of aquatic species, especially fish. Heavy metals are crucial pollutants in aquatic ecosystems and can be among the major factors influencing the health of consumers. The purpose of this essay is to conduct a systematic review of studies that have assessed the concentration of heavy metals in the muscle tissue of certain fish species in these waters, spanning from the year 2006 to 2018. This meta-analysis study was performed on 1182 muscle tissues of Pampus argenteus, Platycephalus indicus, Lutjanus johnii, javelin grunter, Johnius belangerii, Otolithes ruber, Scomberomorus commerson, Scomberomorus guttatus, Epinephelus coioides, caught from the Persian Gulf and the Oman Sea, in order to investigate the amount of these metals. Also, the safety of food intake and the comparison with the standards were investigated. The THQ and HI indices were found to be less than 1 in the all species of fish for adults, but for children only in Scomberomorus commerson in HI index is more than one. The amount of mercury, zinc and lead in the all pecies of fish, cadmium in Lutjanus johnii and javelin grunter and nickel in Scomberomorus guttatus and Epinephelus coioides were lower than all standards. The daily and weekly absorption rates for all studied metals were lower than the authorized JECFA Committee due to fish consumption. Also, the lowest amount of allowance for studied metals was found mercury in Scomberomorus commerson, lead in Johnius belangerii and cadmium in Platycephalus indicus. It seems that high use of the Platycephalus indicus in terms of the studied metals has led to health risks in children. Therefore, environmental protection, which it has been influential in creating nutritional health problems, is considered a necessity.

The Mediterranean-Arab (Arab-Med) Corridor of India to Europe is an emerging multi-faceted trade corridor that could fundamentally alter trade patterns between the Indian Ocean region, the Middle East, and Europe by creating a crescent of trade connectivity on the southern edge of Eurasia from the coasts. The Arabian Sea of India will change to the eastern Mediterranean coast of Greece. For India, this new corridor is a strategic paradigm shift with huge geopolitical implications that could change its role in the Eurasian economic order. Based on this, the current research, which was carried out in a descriptive-analytical way, seeks to answer the question of what effect does the Arab-fashion corridor have on the new architecture in the trans-regional connection? The hypothesis of this research is that the Arab-Med Corridor is creating an alternative trans-regional trade architecture in which the UAE ports can act as the connecting point of the Indian Ocean to create a separate trade corridor from India to Europe and India to The title introduces a new power to the world with the ability to create transregional commercial architecture. The establishment of a Mediterranean terminal - from Haifa to the European mainland at the Greek port of Piraeus - means that Indian goods sent to UAE ports can reach the main markets and production centers of Europe.

The Persian Gulf hosts a variety of marine ecosystems, including mangrove forests, seagrass beds, and coral reefs, which have adapted to the challenging environmental conditions of the region to some extent. These ecosystems are increasingly influenced by rapid population growth, economic development in the countries surrounding the Persian Gulf, as well as, the impact of climate change in the region. They are facing mounting pressure from human activities. The influx of nutrients, coupled with the warming of the Persian Gulf, can result in a reduction in the dissolved oxygen concentration in the water. Consequently, the simultaneous occurrence of warming, reduced oxygen, and acidification in the Persian Gulf has become a significant challenge for its valuable ecosystems. According to studies, hypoxic areas in the Persian Gulf in mid-autumn can extend to more than 50,000 square kilometers. The occurrence of hypoxia in the Persian Gulf during late summer is confined to two primary areas in the western and central regions. In the eastern Strait of Hormuz, hypoxic conditions are observed in the near-bottom layer from early summer to mid-winter in areas distant from the Gulf's outflow. The reconstruction of dissolved oxygen concentrations in recent decades also indicates a declining trend accompanied by an increase in the extent and duration of hypoxia in the Persian Gulf. The degradation of water quality in the Persian Gulf, in addition to its adverse effects on its valuable ecosystems and consequently on fisheries and aquaculture in the Gulf, can significantly impact the Gulf of Oman and even the Arabian Sea in various ways, exacerbating the conditions of Oxygen Minimum Zones (OMZ) in these expansive seas. The Gulf of Oman and the Arabian Sea naturally and permanently host the widest and thickest OMZ in the world ocean. Depths exceeding 400 meters in the Gulf of Oman exhibit suboxic conditions (oxygen concentration less than 6 µmol/kg) during both summer and winter. The OMZ in the Arabian Sea and the Gulf of Oman has intensified over the past few decades. Oxygen levels recorded in 1960 in the core of the OMZ in the Arabian Sea and the Gulf of Oman ranged from 6 to 12 µmol/kg but have now dropped to levels below 6 µmol/kg (suboxic). This intensification of the OMZ in the Arabian Sea and the Gulf of Oman has adverse effects on the ecosystems of this region and the livelihoods of dependent populations. Marine organisms residing in the near-bottom layer or surface sediments are most affected by the expansion and intensification of hypoxic and suboxic conditions. Oxygen deficiency leads to a decline in the biodiversity of benthic communities, promoting resilient species such as polychaeta in surface sediments. The reduction in oxygen levels in the Arabian Sea has significantly influenced the composition of phytoplankton communities, the vertical migration of zooplankton, and myctophidae in the water column. The expansion and intensification of the OMZ, with its adverse impacts on fishing and aquaculture, also carry socio-economic implications for residents of the coastal areas of the Indian Ocean, the Gulf of Oman, and the Arabian Sea. Considering the prevalence of seasonal hypoxic conditions in the Persian Gulf and permanent suboxic conditions in the Gulf of Oman, addressing this trend and mitigating its environmental and economic impacts in the region is crucial. Management and policy strategies to halt or reduce the effects of oxygen depletion in the Persian Gulf and the Gulf of Oman can be classified into three main categories: a) ecosystem-based mitigation measures for environmental restoration and protection, b) adaptation-based measures to restore and protect marine organisms and fisheries, c) implementation and maintenance of monitoring programs and analysis of the information obtained. In essence, efforts to integrate research, management, and policy actions in oceans and seas across all biological, geochemical, and physical disciplines, addressing all climate change-related issues such as warming, acidification, and oxygen reduction, and involving all academic, industrial, governmental, and regulatory sectors, constitute the most effective roadmap recommended for combating the impacts of climate change on marine resources.

Screening and identification of bacteria associated with sponges is an important step in the discovery of new drugs. The purpose of this research was to isolate and identify bacteria associated with sponges around Hormuz Island and to find bacteria that produce metabolites that inhibit the activity of alpha-glucosidase and alpha-amylase enzymes.

In this study, 25 samples of Haliclona and Niphatea sponges were collected from 6 stations. Identification was done based on phenotypic characteristics. Bacteria were cultured in broth nutrient medium and their secondary metabolites were extracted by ethyl acetate. The inhibition rate of metabolites against alpha-amylase and alpha-glucosidase was evaluated based on colorimetric methods. The toxicity of metabolites against normal umbilical cord endothelial cell line was investigated. The productive bacteria were identified by polyphasic taxonomy approach.

A total of 105 bacteria were isolated. Vibrio and Bacillus bacteria with 32.81% and 17.19% in Haliclona sp. and 19.51% and 34.15% in Niphatea sp. The metabolites extracted from 3 isolates inhibited amylase enzyme activity with IC50 values ranging from 0.248 to 366.8 µg/ml. Also, 4 isolates produced inhibitory metabolites against alpha-glucosidase enzyme in IC50 values from 159.4 to 670.9 µg/ml. Based on the results of polyphasic identification of capable isolates including Bacillus pumilus HH 165, Pseudomonas lurida HH 124, Streptomyces sp. HN 235, Bacillus tequilensis HN 231.

In this study, 3 strains of bacteria producing inhibitory compounds, including alpha-ambellase and alpha-glucosidase enzymes, and without cytotoxicity were identified. The mentioned bacteria can be suitable candidates in diabetes studies.

This study aimed to identify the gastropod fauna in the intertidal areas of Kharg Island by differentiating the families Trochidae, Planaxidae, Turbinidae, and Muricidae using a scanning electron microscope (SEM). Gastropod sampling was conducted at five stations in the intertidal zones of Kharg Island (depths less than 1 meter) during the spring and winter of 2015. The samples were frozen and transported to the laboratory. Following a morphometric study, the organic matter in the oral cavity of the gastropods was digested, and their radulae were isolated and prepared for SEM analysis. Five species were identified in this research: Trochus firmus, Trochus erithreus (Trochidae), Turbo radiatus (Turbinidae), Planaxis sulcatus (Planaxidae), and Thais savignyi (Muricidae). The radula types were ripidoglossan in Trochus firmus, Trochus erithreus, and Turbo radiatus; taenioglossan in Planaxis sulcatus; and stenoglossan in Thais savignyi. The radulae of these gastropods differed in the shape of their central, lateral, and marginal teeth. Therefore, the evaluation of radulae using a scanning electron microscope is an effective method for more precise identification of gastropods.

Different studies conducted on the sediments of the Persian Gulf, strait of Hormoz and the Sea of Oman show that the amount of nickel as a toxic metal in these water bodies is more than its threshold effect level. In order to determine the risk of nickel for benthic organisms, the sediment samples of these water areas were subjected to sequential extraction and analysis in order to determine the bioavailability of nickel and subsequently the level of biological risks to benthic organisms.

In this study, the surface sediments of 5 stations in the Persian Gulf, the Strait of Hormuz and the Sea of Oman were analyzed in order to determine the total nickel concentration and determine the bioavailability of nickel during 6 successive extraction stages. Total nickel concentration was measured by Inductively Coupled Plasma Mass Spectrophotometer (ICPMS) and nickel concentration, which was extracted during 6 stages were analyzed by Atomic Absorption analyzing instrument (Furnace).

The results showed that the concentration of nickel in the monitored stations varied between 96 and 113 mg/kg, which is more than the nickel threshold Effect Level (TEL: 15.9 mg/kg). The results of consecutive extraction in 6 stages showed that the concentration of stages 1 and 2 (accessible part of metals for benthic life) was lower than the detection limit of the instrument and their concentration can be neglected.

The amount of nickel in the third stage of extraction (bonding with oxide or hydroxides of iron and manganese) was much lower than the TEL (15.9 mg/Kg) and under environmental changes and redox conditions, the bioavailability of nickel will be lower than the TEL. The results showed that although the nickel pollution in the coastal sediments of the Persian Gulf, the Strait of Hormuz and the Sea of Oman was more than the TEL; but due to the low exchangeable part, the current pollution is not considered a serious risk for the marine life.