فصلنامه اقیانوس شناسی
پیاپی 47 (پاییز 1400)

International obligations of the Flag State for the unauthorized utilization of its Flag Ship from the marine resources of the Exclusive Economic Zone of the Coastal State or the High Sea is one of the new issues in the Area of international responsibility law. At the same time, in accordance with the provisions of the Draft State Responsibility, the Flag State has international liability for violations of its Flag Ship. However, this theory fails due to the non-compliance of some of the international liability requirements in the Area of the law of the sea.

The research method is descriptive-analytical and critical, has innovations and comparative achievements. An examination of the various dimensions of this situation is intended to answer a question in this article which is important. The main question of the research is what are the international obligations of the Flag State in the utilization of the High Sea and the Exclusive Economic Zone?

Research findings show that the Flag State is obliged for ensuring that it Flag Ship cooperates with the Coastal State about the Exclusive Economic Zone’s management and conservation programs. In addition, the Flag State has to collaborate with the Coastal State and the Regional Fisheries Organizations to maintain marine living resources in the Exclusive Economic Zone and the High Sea.

Unauthorized exploitation of aquatic resources is carried out by natural and legal persons. These persons are subject to Article 62(4) of the Convention on the Law of the Sea, which stipulates that national of other states must take the necessary measures to protect natural resources in accordance with the laws and regulations of the Coastal State in order to exploit fish in the Exclusive Economic Zone of the Coastal State or the High Seas. In these circumstances, the conduct of natural and legal persons is contrary to the regulations under the jurisdiction of the Flag State does not attributed to that state. The Flag State is not responsible for the illegal actions of the Flag Ship in the illegal exploitation of fish in the Exclusive Economic Zone of the Coastal State or the High Seas. At the same time, the obligations of the Flag State to oblige the ship carrying its flag to comply with international regulations do not create liability for the illegal actions of the said ship, but this method of regulation is also not conducive to the development of relations between the Coastal States and other states in the exploitation of their surplus sea resources. This is because the Flag State is not responsible for compensating the damage caused by the Flag Ship under the above conditions. This inference is supported by the application of the International Tribunal for the Law of the Sea’s advisory theory, which implies a lack of absolute responsibility for the Flag State under these circumstances, and the entire responsibility lies with the offending ship, the master and the ship owner, assuming non-compliance with fishing regulations. Therefore, the Coastal State or the Regional Fisheries Organization can in this case sue the master responsibility or the owner of the ship for not complying with the requirements related to fishing in the exclusive economic zone.

In the present study, the possibility of using macrobenthos as a biological indicator to assess the level of contamination of the rust estuary with heavy metals has been investigated.

Sampling was performed in 2016 from 4 stations in Zangi estuary at full tide.Sediment was harvested from each station using Van Wen (with a cross section of 0.025 m2) to identify benthos, determine heavy metals in sediment, determine organic matter and granulate sediments. In all 4 stations, clay particles formed the main part of the sediments.

The range of organic matter was 6.90-6.98%, with station 3 having the highest percentage and station 4 having the lowest percentage of organic matter. The identified macrobenthos in Zangi estuary were divided into five categories: Bivalvia, Gastopoda, Polychaeta, Crustacea and Fish and 26 genera and species. Station 1 with 13 species had the highest number of species and Station 2 had the highest number of macrobenthos per square meter and the highest Shannon diversity and uniformity index. Species of Hydroides sp. Polychaeta with 25.97% had the highest frequency in the population of Zangi estuary macrobenthos. Accordingly, Polychaeta with 49.1% and Bivalvia with 37.21% had the most abundant category and fish with 0.86% had the lowest frequency. Polychaeta class in stations 1 and 4 with 63.26 and 56.1% and Bivalvia class in stations 2 and 3 with 44 and 33.06%, respectively, had the highest percentage. Zinc, nickel and chromium had the highest concentrations with averages of 32.41, 23.13 and 19.16 mg/kg.Selenium had the lowest concentration in all 4 stations. The mean concentrations of heavy metals in stations 2 and 3 were significantly less polluted with stations 1 and 4 (p <0.05). Calculation of the degree of pollution in 4 stations of Zangi estuary showed the degree of severely polluted for these stations. Based on the contamination factor, except for vanadium at all stations and lead metal at station 2, which is in the highly contaminated range, other metals were in the low to high contamination range. Thus, the concentration of all metals in the bell ring was in the alarming state.

The results of the present study showed that the first and most important factor influencing the distribution of estuarine macrobenthos was the percentage of bed clay particles, heavy metals such as cadmium, lead, nickel, vanadium, chromium and zinc and then the organic matter in the bed. Also, copper metal had the least effect and correlation with the number of macrobenthos among the studied metals.

The Arctic and Antarctic play very important role in the thermohaline circulation and Earth’s thermal balance. Due to the very important role of polar sea ice and the significant reduction of ice in these two oceans, climate changes’ effects and global warming are more pronounced in these areas. Reducing the sea ice thickness and increasing its transparency, exposes ocean water to sunlight and leads to an increase in water surface temperature which has intensified melting of polar sea ice in recent years. The ice-free ocean has been exposed to direct winds and common polar storms, not only drastically changing the water column, but also intensifying the melting of surface ice. On the other hand, because the ocean surface layer is the interface layer between the atmosphere and the deep part of the ocean, it is of special importance. In this study, monthly variations of the mixed layer depth and its physical properties in Franklin Bay in the Arctic Ocean are investigated. 

The data used in the present study are part of the data obtained during the CASES international program conducted between September 2003 and August 2004 in order to investigate the ecological consequences affected by the landfast ice variation due to the climate change. The data used in this study were sampled twice a day at a fixed station in Franklin Bay between late December to early June. In this study, the mixed layer depth is estimated based on the density profile using the threshold method with threshold values of 0.05, 0.2, 0.4 and 1 kg.m-3. In order to assess the most appropriate threshold value the estimated depths were compared with visual mixed layer depths using a number of statistical indicators. Thereafter, monthly and seasonal variations of the mixed layer characteristics including temperature, salinity, density and depth were investigated.

The results showed that in the study area the most appropriate threshold value for estimating the mixed layer depth is 0.4 kg.m-3. The findings also showed that in Franklin Bay, the mixed layer depth and its characteristics have monthly and seasonally variations. These variations are impacted by meteorological variations such as the temperature and wind intensity and direction. The mixed layer depth started to increase from the beginning of the observation until it reached its maximum value in April and thereafter decreased. On the other hand, the temperature, salinity and density of the mixed layer started to decrease, increase and increase, respectively, from the end of autumn, and after reaching its minimum, maximum and maximum value in April, it started to increase, decrease and decrease. The temperature of the mixed layer during the winter and spring was close to freezing point and in spring it was colder than the winter. The salinity range during the winter was larger than that during the spring and in general, salinity in spring was higher than that in the winter. In addition, observing the wind intensity and direction showed that the prevailing easterly winds between 12 and 20 December 2003 leads to an ice edge upwelling in the Franklin Bay. Upwelling brought relatively warm and salty waters to the surface and the mixed layer was totally destroyed during this period.

Oceanic mixed layer depth is affected by various parameters such as air temperature, ice freezing/melting, intensity and direction of the wind, as well as other oceanic processes such as upwelling. As the air temperature gradually decreases salt rejection due to the ice formation starts. Increasing salinity at the water surface leads to the increased surface layer density which brings convection throughout the cold season, as well as increasing the mixed layer depth. The mixed layer depth reached its maximum in early April, then started to reduce with higher temperature which causes ice to melt. Ice melting results in an increase in surface fresh water that making surface water stratified which leads to decrease the mixed layer depth.

Microalgae are rich sources of active metabolites, which today are considered as important sources of biofuels in addition to medicinal and food uses. In this study, ribosomal markers were used to determine the phylogenetic posation of microalgae species which isolated from the southern coast of the Caspian Sea.

For molecular studies, microalgae grown in suspension culture medium were precipitated using iron (III) chloride solution. After extraction of genomic DNA by freez- thawing method, the gene loci encoding ribosomal subunits (16srDNA) were amplified using 36 pairs oligoes by polymerase chain reaction (PCR), the amplified gene loci were inserted into the pTZ57R /T vector by TA cloning technique then transformed in the Dh5α bacterial and sequenced follow by purification.

Fourteen pairs of primers showed acceptable amplification of target gene in the microalgae genome. The obtained sequences were edited by Vector NTi ver. 11 software and then blasted at the NCBI. Sequences with more than 90% similarity were selected and the molecular distance of the data was estimated by MEGA 6 software and phylogenetic analyzes were performed by calculating the maximum short molecular trees (Maximum Parsimony, MP) for the sequence of the studied genes, and Then, Bootstrap 1000 index was used for analysis to test the accuracy of the nodes.

The results of phylogenetic tree and similarity matrix with Maximum Parsimony method for all 14 gene regions showed that the studied species has the lowest genetic distance with the algal strain Spirulina laxissima.

Today, the increasing failure of chemotherapy and antibiotic resistance displayed by pathogenic bacteria infectious agents have caused the screening of new secondary metabolites with various chemical structures of marine crustaceans, molluscs and echinoderms with desirable antibacterial activity. This study was designed to determine the antimicrobial effect of muscle wall methanol and acetone extracts of four species of sea cucumber (Holothuria arenicola, H. leucospilota, Stichopus hermanni, S.horrens) in Chabahar coasts on some rainbow trout (Oncorhynchus mykiss) pathogenic bacteria (Lactococcus garvieae, Aeromonas hydrophila, Yersinia ruckeri and Streptococcus iniae).

An experimental study was conducted at in vitro conditions. Experimental variables include sea cucumber species, different concentrations of extracts and bacterial strains. After preparing extracts of mentioned sea cucumber by maceration method, the antimicrobial effect of outcome extracts from their muscle wall were investigated by two different methods disk diffusion and well diffusion.

At acetone extract of S.horrens, the highest growth inhibition zone for Y. ruckeri and A. hydrophila bacteria at 12 mg/mL concentration in disk diffusion method (11.10 and 13.03 mm) were seen respectively. Different concentrations of methanol extract of S. hermanni, H. leucospilota and H. arenicola were inactive on the tested bacteria. While, Minimum Inhibitory Concentration (MIC) of acetone extracts of S.horrens for Y. ruckeri and A. hydrophila was 0.625 and 1.25 mg/mL respectively and Minimum Bactericidal Concentration (MBC) for Y. ruckeri and A. hydrophila bacteria were 2.5 and 2.5 mg/mL respectively in well diffusion method.Generally, it type of extract, sea cucumber species and also bacterium strain are influenced on growth inhibition zone, MIC and MBC. Acetone extract of S. hermanni and S. horrens sea cucumbers can prevent the growth of Y.ruckeri bacterium tested by both methods (disk diffusion and well).

The aim of this study was to investigate the morphology and molecular identification of oyster knife Solen dactylus. Razor clams are edible bivalve molluscs that fetch high prices in international markets.

For this purpose, sampling of this species was performed from the designated station in Khowr-e Guban, south of Shadegan wetland. Morphological identification was first performed using valid identification keys. Then, to ensure assurance, molecular identification of the species was performed using amplification of mitochondrial COI region. The resulting genomic sequences were analyzed using Chromas, BioEdit, and Mega 7 software. Blast sequences were also identified in NCBI and phylogenetic tree was constructed.

The results showed that the Solen strictus species and the Solen marginatus species and the present study species (Solen sp.) are in a sister clade and derived from a common ancestor. The sequence of amplified gene fragments with specific COI primers showed 83% similarity to S. strictus, while the two species are similar in appearance, but in morphological studies and the use of identification keys specifications such as palliative tentacles on the front of the foot, small teeth, and measurement of oyster length and width, which are characteristic of S. dactylus and do not exist in S. strictus and S. marginatus species.

Therefore, according to morphological and molecular results, Solen sp. species is probably the same as S. dactylus. This species was registered in the NCBI database with the acceptance code QGL52628.

Determining the age and growth of fish is vital in fisheries management and biology. This information is the foundation for modeling aquatic population dynamics and is employed to analyze fishing data. The relationship between length and weight and some other growth indices of Caspian Vimba persa was studied from autumn 1996 through spring 1997 on the southwestern coasts of the Caspian Sea (Astara, Anzali and Kiashahr).

Sampling was carried out seasonally using beach seine net at three fishing regions e.g., Kiashahr, Astara and Anzali. Each season 8 samples were taken at designated sampling stations (a total of 24 fish each season) except for 9 samples at Anzali stations in the autumn (25 samples in total). In total 73 specimens of Caspian Vimba persa were collected from the sampling stations.

Fish age varied in the range of 0+- 3+ in both females and males. The highest length frequency was observed in the length group of 14-25cm. Mean total length in the whole population, females and males were 18.05± 2.38; 18.61± 2.73 and 17.14±1.29 respectively. Mean total weight in the whole population, female and male were 65.62 ±33.98; 73.89± 39.43 and 52.32±15.78 respectively. Mean fork lengths in the whole population, female and male were 16.05± 2.66; 16.68±2.49 and 15.46± 1.17 respectively. Mean gonadosomatic index was 6.88 ± 4.23. Mean hepatosomatic index and obesity coefficient were 0.98±0.51 and 1.04±0.10 respectively.

Analysis of the obesity coefficient showed that the species upholds ‘good’ growth rate.  The Length-weight relationship for the whole population was W = 0.3403L3.403, female W= 0. 003 L3.365 and male W= 0.0047L3.2719. The t test showed that the obtained bvalue was greater than 3 thus the species has a positive allometric growth pattern. Since within the whole sampled fish the W> L3 and CF = K> 1 (obesity coefficient was greater than 1) relationship was applied, it can be concluded that the Caspian Vimba persa are more obese than usual which indicates good feeding condition of fish in the southwestern part of the Caspian Sea.

The abstract is one of the most important parts of a paper. The abstract must be presented on a Plastic products have a growing trend in the world due to ease of production, flexibility, strength and economic efficiency. These products are used in a wide range of industries, including construction, automobiles, marine industries, aerospace, electricity and electronics, transportation, medicine and pharmaceuticals, cosmetics, paints, agriculture, home appliances, etc. It can be said that today, plastic has become a part of human life, and no one can claim that who don’t related to plastic on a daily basis. This is illustrated that our environment is facing a huge amount of plastic pollution in air, soil and water. Also this concern is exacerbated by the slow rate degradation of these compounds in nature. The presence of compounds such as phthalates and bisphenols in the structure of plastics, that their carcinogenic effects and hormonal disorders have been reported in humans, can also intensify human concerns in the public health along with environmental issues. Scientists attempts to control the unbridled expansion of plastics in the environment, by changes in the chemical structure of them into biodegradable forms, finding alternative products, and also categorizing main sources of contamination. The largest enclosed water body of the Caspian Sea, with its unique sturgeon fish species and fragile ecological conditions, is one of the most important habitats. Due to the growing trend of development in the surrounding countries of the Caspian Sea, microplastic pollution is increasing in this ecosystem. Owing to ecological importance of this habitat, the present study was conducted on the southwestern shores of the Caspian Sea in the province of Guilan

In this study, sampling of surface sediments from the southwestern coastlines of the Caspian Sea was performed at 13 stations in September and October 2016.  About 3kg of Sediment samples were collected from the surface section of 0-5 cm at each station.  After dewatering, the samples were dried at 60 ° C and then passed through a sieve with a 5 mm mesh for homogenization. In order to separate the microplastics from the sediment samples, a two-step extraction method based on density was done by two saturated solutions prepared from NaCl and NaI. Number of fragments, shape and color separation of microplastics were performed using stereo microscope. The Fourier transform infrared spectroscopy device was also used to identify the chemical structure of microplastics.

A total of 909 microplastic fragments were obtained from sediment samples of the region. The results showed that the amount of microplastics in tourist and commercial centers such as Astara, Bandar Anzali, Caspian free zone and Chamkhaleh regions were more than other stations. Studies have demonstrated that in terms of shape, microplastics separated in three categories including: filaments, disintegrating fragments and membranes. The consequences of spectroscopy demonstrated that the microplastics in the study area are composed of 4 different types of polymers: polyethylene, polypropylene, polyester and polystyrene. The outcomes also displayed that the average microplastic particle size is 1.43 ± 1.06 mm in the region.

According to the results, commercial and tourist sectors have a major role in the spread of micro-plastics in the study area. The continued use of fishing nets and plastic ropes in the fishing industry are other sources of this type of pollution in the region.  Among the collected samples, microplastics with polyethylene structure had the highest amount between the groups of polyester, polypropylene and polystyrene. This, illustrates the use of large amounts of plastic bags and bottles in tourist areas has important role in increasing of this type of polymer. The small size of microplastics, in addition to greater ability to be swallowed by aquatic animals, also shows their extraordinary potential as a substrate for the absorption of other pollutants.

Familiarity with the strategies of entering global markets is one of the important components of firm success in achieving greater market share, which they use to overcome the uncertainty caused by the unknown environment, especially in critical situations. The main purpose of this study is to identify the critical success factors in the selection of strategies to enter foreign markets and has been formulated based on the study of companies exporting the country aquatic industry.

First, by studying the library of internationalization strategies of firms as well as the vital factors of success in choosing a strategy in this field, and using a mixed method research (qualitative-quantitative) in 30 companies exporting seafood through a multiple case study and tested with Theme analysis method, fuzzy Delphi technique, structural-interpretive modeling and partial least squares technique have been analyzed and prioritized. Then, businesses are categorized in terms of facing with Covid-19 pandemic, and the critical success factors for strategy selection process are examined.

Based on the research findings, the strategies used by the exporter firms are: export, foreign direct investment, license and strategic alliances. The results also show that the motivation of business managers, technological advancement level of readiness for internationalization, inter-firm relationships and innovativeness are among the vital factors of success in choosing a strategy to enter the market.

Opportunity-creator firms have innovative and global managers, and based on this, a new classification of firm managers and their approaches is presented.

Spirulina platensis is one of the most common and widespread species of cyanobacteria that has been extensively studied in various fields of the food and drug industry. Extensive tests performed on Spirulina show that this cyanobacterium is a unique source of natural bioactive substances with potential healing properties. The aim of this study was to optimize the extraction of the bioactive peptide Spirulina platensis by the enzyme alkaline protease and to investigate the anti-inflammatory properties of the extracted spirulina peptides in mice with intestinal inflammation.

For this purpose, the RSM response surface methodology determined the optimal performance of the enzyme and the extracted peptides were dried in a freeze-dried dryer to determine the molecular weight of the peptide by electrophoresis SDS page space. The resulting peptides were stored at -20°C. To evaluate the anti-inflammatory effects in 25 Balb/C mice with inflammation 4% acetic acid was induced. After ensuring inflammation of peptides with two concentrations (1.6 and 3.8 mg/kg) and omeprazole as positive control and water as negative control to Balb/C mice with intestinal ulcer, gavage and effect These treatments were evaluated on the repair of inflammation.

The results showed that the optimal conditions of enzymatic hydrolysis of alkaline protease were obtained at 60°C, 210 minutes and pH 7.5. Histological

The presence of inflammation in the control group and in mice with peptide at a concentration of 3.8 (mg/kg) intestinal tissue, crypt and intestinal mucosa was completely regenerated during treatment. In mice treated with peptide at a concentration of 1.6(mg/kg), a relative improvement was achieved and the crypt was regenerated, but damage to the intestinal mucosa was still observed. The alkaline phosphatase enzyme is low in mice that receive the peptide, indicating an improvement in inflammation in these mice.

According to the results of this study, the bioactive spirulina peptides were able to treat inflammation in the intestines of mice.