فصلنامه اقیانوس شناسی
پیاپی 48 (زمستان 1400)

Nostoc species have gained much interest as a natural source of many secondary metabolites that have exhibited pharmacological properties. They synthesize UV-protective substances such as mycosporine-like amino acids (MAAs) or scytonemin to minimize the deleterious effects caused by UV radiation. In this research the effects of UVB radiation on increasing amount of UV-protective substances (scytonemin, OS-MAAS), and growth parameters such as photosynthetic pigments, protein and sugar content were studied in cyanobacteria Nostoc linckia.

For this purpose, 14-day algal cultures were treated with UVB rays for 1, 2 and 3 hours per day for 5 days. After treatment, the growth rate according to fresh weight measurement and other biochemical parameters according to colorimetric methods were assayed. Data were analyzed by one-way analysis of variance, and the significance of the differences was estimated by Duncan’s multiple comparison tests.

UVB treatment resulted in lower fresh weight of Nostoc algae. Algae exposure to 3 hours UVB, showed an increase in OS-MAAS content. The amount of scytonemin increased up to 3 times in 3 hours UVB treatment. The algae treated with UVB had more chlorophyll a and total carotenoid content but phycobiliproteins content reduced in this treatment. Total protein and total sugars were not affected by UVB treatment.

The results showed that this UV treatment method, in addition to significantly enhancing the anti UV compounds of the algae, would not reduce the biomass.

The Persian Gulf is a shallow, semi-closed environment with an average depth of 35 meters and a maximum depth of 90 meters, connected to the Gulf of Oman through the Strait of Hormuz. The Persian Gulf is one of the main sources of saline water masses in the world. In the past, passive detectors have been used to track water mass. The use of satellite data in the study of water patterns and masses is a new science. The reasons of satellite data usage are its low costs and its availability. The purpose of this research is to investigate the location of Persian Gulf Water mass (PGW) in both warm and cold seasons which by using satellite data analysis, the distribution and dynamics of the Persian Gulf Water mass have been investigated and its possible areas in the Oman Sea have been identified.

The sea surface temperature of the studied area (47.00-59.45˚E, 22.60-32.00˚N) prepared from the Group for High Resoulation Sea Surface Temperature (SST) of NOAA named OSTIA (by the resolution of 0.05˚), and Sea Surface Salinity (SSS) prepared from NOAA NESDIS STAR (by the resolution of 0.25˚), respectively. First, daily statistical data for six years (2014-2019) were extracted annually, in both warm and cold seasons. Then, temporal mean, maximum, minimum, range and standard deviation were obtained for the whole basin and the means of the basin were illustrated separately for each season. The spatial mean of annual SST of basin in the studied years (2014-2019) was calculated for all cells, but the spatial mean of annual SSS was not calculated due to the lack of data in many cells. Then, the SST and SSS satellite data, according to the 73-years measured historical data, were spatially filtered in MATLAB to obtain the filtered range of SST and SSS and determine the expansion of the PGW mass in Oman Sea.

From the filter of OSTIA satellite data in the warm season of the studied years (2014-2019), it was observed that the PGW mass has shifted, so that PGW mass has gone further and moved to east about 0.12 degrees equal to 14 km in 2016 in compared with 2015 and about 0.08 degrees, equivalent to 9 km in 2017 in compared with 2016. The PGW can be transported in the Oman Sea, 300 to 350 km from the Strait of Hormuz. The width of PGW in the Oman Sea is about one degree (56-57˚E) in the warm season and 2.5 degrees (57-59.5˚E) in the cold season, by annual changes. (The widest expansion happened in 2015.).

This study represents that the difference of the highest daily SST of the warm and cold seasons (35.87˚C and 34.06˚C, respectively) were about 1.8˚C and the lowest daily SST difference of  the warm and cold seasons (18.27˚C and 13.11˚C, respectively) were about 5.16˚C. The average salinity in the warm season is about 34.08 psu to 36.49 psu with a range of changes of 2.4 psu. Whereas the average salinity is in the range of 34.51 psu to 36.50 psu with a range of changes of 2.01 psu in the cold season. Moreover, the surface water of the cold season (by filtered temperature of 28.5-30˚C) is located in the west of Oman Sea (58.5˚E to 59.5˚E). In the warm season, this water progress farther to the middle of Oman Sea (longitudes more than 59.5˚E), which indicates that the PGW mass penetrates more from its subsurface to the Oman Sea in the warm season.

Iran has different populations of Artemia that live in different climates and ecological conditions. Physicochemical conditions of lakes and lagoons have intensified the allopatric Artemia speciation. The aim of this study was to investigate the effect of one of the ions in these climates so that Artemia can be cultivated semi-naturally in some wetlands of Golestan province.

To do this, the effect of four treatments (10, 16, 33, and 50%) of magnesium sulfate instead of other salts on cyst and growth parameters of Artemia franciscana was studied.

There was a significant difference between the experimental groups in the Artemia growth index (P <0.05). Maximum and minimum body lengths were observed in the control and 50% magnesium sulfate groups, respectively. Also, 33 % magnesium sulfate treatment showed a significant decrease in growth rate compared to the control treatment (p <0.05) but did not show a significant difference with 50% magnesium sulfate treatment (P <0.05). At low concentrations of magnesium sulfate growth rate insignificantly decreased in Artemia compared to control treatment. The highest and the lowest survival percentage were observed in control and 50% magnesium sulfate, respectively. On the 15th day, the maximum and minimum survival rate was 83 % and 46% in control and 50% magnesium sulfate treatment, respectively. The highest hatching percentage was observed in the control treatment and the lowest was observed in the 50% magnesium sulfate treatment. Increasing magnesium sulfate concentration significantly decreased the number of nauplii but increased the number of non-hatched cysts (P <0.05). Moreover, the highest number of umbrella stages of Artemia was observed in the treatment with 50% magnesium sulfate. Maximum and minimum hatch efficiency were insignificantly observed in control and 50% magnesium sulfate treatments, respectively. The highest mortality of nauplii was significantly observed in the treatment with maximum magnesium sulfate.

The results of this study showed that magnesium sulfate in high-level amounts limits the hatching and growth of Artemia which should not be introduced to such climates.

Enzymes are selective proteins that catalyze all metabolic reactions found in living organisms. Millions of enzymes are produced by prokaryotes and eukaryotes. Marine sponges have developed a enormous quantity of diverse microorganisms such as bacteria, fungi, viruses, protozoa, and single-celled algae and the nature of the sponge-microbe interaction is diverse. Marine sponge's symbiotic bacteria can comprise as much as 40% of sponge tissue volume. At least 32 bacterial phyla and candidate phyla were described from marine sponges by both cultivation-dependent and cultivation-independent techniques. Symbiotic microorganisms in sponges can be sources of various natural products, because metabolites previously ascribed to sponges have recently been demonstrated to be biosynthesized by symbionts. If symbiotic microorganisms from which some natural products are derived can be cultured, the microorganism could be used in a mass production of the bioactive comopounds. The goal of this research is isolation of Amylolytic bacteria from marine sponges and optimization of bacterial growth and amylase production in most amylolytic isolate. Symbiot bacteria were isolated using serial dilution method and differential analyses done for isolated bacteria. Most effective isolate was selected by using qualitative starch hydrolysis method.

Morphological and biochemical characteristics were studied using Bergey’s manual of systematic bacteriology. Differential analyses were performed by catalase and Gram test TSI, H2S, VP, MR tests. Preliminary screening and quantification of amylase activities were analysed in selected isolates by starch agar plate and dinitrosalicylic acid (DNS) method respectively. In order to optimize the enzyme production, the fermentation process was carried out under M9 medium using various sodium chloride concentrations (2–14%). To evaluate the effect of pH on the production of Amylase, the best amylase producer isolate was cultured at M9 medium with different pH rang 4-8. After incubation time it was subjected to amylase activity assay. Isolate SS1 was grown in M1 medium at 28°C for 7 days. DNA extraction was done using Cinnapure DNA Kit for isolation of DNA from gram positive bacteria. PCR amplification of 16S rRNA gene was performed, the specific actinomycete primers, F27 and R1492 were used to amplify 16S rDNA. The resultant 16S rRNA gene sequences were aligned manually with corresponding almost complete sequences. The 16S rRNA gene sequence search was performed using the BLAST program available from the National Centre for Biotechnology Information (NCBI) and the isolate was identified to generic level Using the CLUSTAL-X Multiple Sequence Alignment Program (Strasburg, France), The Phylogenetic tree was constructed by Neighbor-Joining method using MEGA 6.06. The reliability of the phylogenetic tree was tested by bootstrap analysis using 1,000 replicates.

Biochemical analyses showed that all tests were catalase and Gram positive none of them produced H2S and TSI, MR, VP tests were negative. According to 16S rRNA sequences result the most effective isolate was belong to Bacillus genus and Optimum growth condition was found at 12% NaCl concentration, 35˚C temperature and pH 12. Maximum amylase activity in optimum condition was 109 Unit (one Unit is amount of enzyme that release one microgram of glucose in a minute).

The results showed that enzyme production is related to growth of bacteria conditions and the amylase gene should amplify from selected isolate and clone in suitable host for more studies.

Microplastics have become one of the major and emerging environmental challenges due to their ubiquity in the oceans and their ability to carry toxic chemicals. In recent decades, with increasing production and global demand for plastics, the entry of these materials into marine environments has increased dramatically. Therefore, due to the importance of the oceans and seas in terms of food supply and climate issues, the environmental consequences of such wastes have been considered more than ever. The distant transport, persistence and universal dynamic forces of plastic remains are key aspects to considerate the fate of this material and any potential impacts of plastic remains on marine ecosystems. A plastic remains accumulates chemical contaminants; it is accepted to the world how plastic remains are considered toxic. Because of their potential to bioaccumulation, ingestion of micro plastics can enter human food chains via several pathways. Strategy for control of micro plastics pollution should mostly focus on source reduction and afterward on the development of cost-effective clean up and remediation technologies.

The Discreaption Research Method has been implemented based on library resources, databases, and scientific reports. The hypothesis of this research is the existence of harmful effects of microplastics and its report by researchers.

Microplastics have become one of the major environmental challenges due to their ubiquity in the oceans and their ability to carry toxic chemicals. These pollutants pose a serious threat to the human food chain due to factors such as bioaccumulation and biomagnification. However, developing new methods to reduce the identified risks of bioplastics and microplastics is significant. Also, it should be assessed how intermediate plastic waste creates these key aspects for environmental chemical pollutants.

The term microplastic has only been widely used in the last two decades, although there are still many questions about the extent of their destructive effects. Therefore, due to the limitations of existing studies, further research on sample processing and analysis techniques to control and reduce the entry of microplastics into the water and food chain is needed until standardization and coordination for sampling and recognition of samples are carried out.

 Noctiluca scintillans is a dinoflagellate without armor that has extensive winter blooms in the northern Indian Ocean. Green layers from dense algal masses of N. scintillans were observed in all the studied stations in the winter, PGE 1801 cruise of the Institute of Oceanography and Atmospheric Sciences in the Strait of Hormuz. The aim of this study was to an assessment of the distribution of the bloom in the winter of 2017 in the Strait of Hormuz using field data and remote sensing.

The density of N. scintillans species in the upper layer of water was calculated using closing net samples. The density of other phytoplankton was obtained by direct sampling of water by Niskin sampler. In all stations, the profiles of salinity, water temperature, and chlorophyll A parameters were measured from surface to layer close to the substrate using CTD. MODIS satellite data were used to investigate the distribution and extent of the bloom.

The results of correlation analysis (Pearson) showed a significant relationship between chlorophyll A (values ​​obtained from remote sensing) and the number of N. scintillans cells per liter (R = 0.74, P <0.05).

It seems that the intensity of N. scintillans bloom is higher in the western part of the Strait of Hormuz and the waters near the coast. Also, satellite remote sensing data show that there is a strong correlation between the distribution of N. scintillans bloom and mid-scale eddies in the Strait of Hormuz.

The valuable place of the environment in human societies has always been considered around the world because human survival is measured by its protection. Thus, we need a solution to deal with the negative consequences in order to protect the marine environment of the Persian Gulf and to implement the goals of sustainable development in this region, which is one of the most polluted and vulnerable marine areas. Because the increasing dominance of these factors has created irreparable environmental catastrophes in the Persian Gulf ecosystem that all coastal countries are responsible for preventing them. Accordingly, the 2030 Sustainable Development Goals have set out a codified set of tasks for countries, to be fulfilled by 2030. Moreover, taking into account the Millennium Development Goals, it offers solutions to solve the earth’s environmental problems in the field of poverty, clean water, clean energy and state-of-the-art technologies. Certainly, achieving the goals of sustainable development and increasing the quality of life of human beings in accordance with current and future needs is possible by achieving the tools of economic growth along with social quality and transforming to sustainable production methods and consumption patterns by establishing environmental balance.

This article studied analytically and through library research while examining the negative consequences and obstacles to progress, also refers to the approach of positive consequences and offers solutions to overcome obstacles.

The results of this article show that necessary and unavoidable to study the consequences and to establish a procedure to achieve the proposed indigenous indicators and adapt of sustainable development goals in the Persian Gulf regions level;  because achieving positive results in this matter is achievable through providing balance between economy, society and marine environment.

According to the analysis performed, considered as a fundamental solution for future research to eliminate marine environmental pollution, the protection of the marine environment of the Persian Gulf has been made possible by supporting and conducting the goals of sustainable development of the 2030 instrument and implementing it in the region so as to pave the way for attainment of sustainable development in marine regions by eliminating the barriers and negative consequences that impede sustainable development. Eventually, for the implementation of the 2030 instrument in the regions and countries of the Persian Gulf, governments are obliged to adopt the goals of sustainable development with regard to the appropriate environmental conditions. Hence, one of the basic objectives of the present paper is to explain and design indigenous indicators proposed for sustainable development across the regional areas of the Persian Gulf.

Estuaries are very important aquatic systems due to importing/exporting large amounts of organic and inorganic materials from natural and anthropogenic sources to seas.

In the present study, suspended particulate matters (SPMs) were collected from Navrud River in to laboratory and sequential extraction procedure was conducted to determine element concentration. Adsorption and desorption of heavy metals (Cu, Zn, Pb, Ni, and Mn) was determined under the effect of various parameters (Salinity, DOC, pH and Nitrate).

Based on the results of adsorption and desorption testing, when SPMs enter estuarine mixing zone at different salinities, Cu, Ni and Zn adsorbed to SPMs by 6.41, 3.03 and 2.09, respectively. Mn and Pb desorbed from SPMs by 97 and 2.09 ppm. Base on cluster analysis, Nitrate and pH dominate the adsorption and desorption of Mn and Pb during experimental blending. Also, salinity and dissolved organic carbon control adsorption and desorption of Ni and there was a high correlation between this element and salinity and DOC.

Water resource managers will make better decisions with more accurate information, the actual amounts of heavy metals transported by rivers to the sea are different from those taken for absorption and desorption. Therefore, the absorption and desorption of heavy metals in the estuary is of great importance due to the possibility of different salinities.

Concluding the "Convention on the Legal Status of the Caspian Sea" which is known as "Aktau Convention" in 2018, the Fishery Zone was recognized as one of the four regions of the sea. Regarding to the Conventionchr('39')s silence on many of the jurisdiction issues in the region, the purpose of the paper is determining the jurisdiction of the Caspian Sea coastal states in the light of international law.  

the present topic was done by descriptive-analytical method and in regard to gathering the mainly qualitative information of research using library method by investigating withinthe books, authoritative papers  and related websites.

Studing Persian legal texts as well as international comparative studies shows that the present article has been innovative compared to the aforementioned articles in terms of the scope of jurisdiction and the time studied in the fishing area. In other words, the study of this article includes the "legislative", "judicial" and "executive" jurisdiction of the coastal states in the Caspian Sea in recent times and after the concluding the Aktau Convention.

The results of the paper shows that According to the international law, coastal states have Legislative, Judicial and Enforcement jurisdictions on some  issues in the fishery zone widely and extending the mentioned regulations by the five coastal states to the Caspian Sea is the best way to solve future jurisdiction challenges.

According to researches, sponges produce the most secondary metabolites with biological activities among aquatic animals. In this scientific study, we investigated the antifungal, antibacterial and cytotoxic activities of terpenoid extracted, phytol, from Dysidea avara of Hengam Island, Persia Gulf.

In this study, dried sponge powder was extracted in acetone by maceration method. Then, the terpenoids were extracted by silica gel column chromatography from acetone extract by using n-hexane, ethyl acetate and methanol solvent. Biological activities of extracted compounds were evaluated by   XTT assay on KB / C152, HUT-78 / C185 cancer cell line and Hek293 healthy cell for Cytotoxic, tubular dilution test on Escherichia coli strains, Pseudomonas aeruginosa salubilosa, Klebsiella, Klebsiella Typhi, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Nocardia brasiliensis and the fungal, yeast strains, Aspergillus fumigatus and Candida albicans for antibacterial and antifungal test. The selected phytol was identified by gas chromatography.

The phytol compound was killed fifty percent of cancer cells at concentrations of 67.21μg/ml on oral epithelial cancer cells and concentrations 56.10 μg/ml on lymphocyte cancer cells. Phytol compound were killed gram-positive bacteria Staphylococcus aureus, Bacillus subtilis and Bacillus cereus at 200-300 µg/ml concentrations and at 1000 -2000 µg/ml concentrations Gram-negative bacteria Escherichia coli, Pseudomonas salmonella and the fungal Aspergillus, yeast strains C. albicans. This study investigated the effects of phytol fraction extracted from D. avara sponge from the Hengam Island, Persian Gulf. The cytotoxic, antibacterial and antifungal activities of extracted fractions have been demonstrated.

The results showed that complementary experiments, isolation and purification of bioactive compounds can be an effective step in the extraction of natural compounds for the production of drugs, cosmetics and food.