فصلنامه اقیانوس شناسی
پیاپی 52 (زمستان 1401)

 Gelatinous zooplanktons are unknown, mysterious and widely distributed; they are known as key components of ocean ecosystems. In the past two decades, blooms have been observed in some parts of the world under the influence of various factors, including human activities, intensification of the eutrophication, climate changes, and increasing fishing activities, but some other studies did not achieve to severe and unusual blooms. Currently, there is no information about community structure and factors affecting the distribution pattern of gelatinous zooplankton in Iranian marine water bodies, therefore, in this research, the identification, spatial distribution and temporal succession of their different groups (Cnidaria, Cetenophora, Thaliacea) from northern surface-coastal waters of Bushehr were surveyed.

 In this survey, gelatinous zooplankton fauna from the northern coastal/estuarine waters of Bushehr were analyzed during summer of 2017 to spring 2018. Also, in each sampling, the water depth of the sampling site, Secchi depth, pH, and salinity were measured.

5 species of gelatinous zooplankton including three species from hydromedusae Eutima gegenbaueri, Eirene viridula and Clytia discoida, one species of salp Diphyes chamissonis and one combed species Pleurobrachia pileus were identified and reported for the first time from the Persian Gulf. Also, the density of Pleurobrachia pileus reached 3411 ind.m-3 at its blooming (end of September) and was introduced as the dominant species of gelatinous zooplankton in the region.

Based on results of the Multivariate MDS analysis on physical parameters comprising water temperature, dissolved Oxygen, salinity, Secchi depth, depth of sampling stations and Chla, a twice-yearly passage/seasons (two-season time differentiation pattern)  was detected in the region and based on PCO test, only Frake creek-estuary was differentiated from other studied stations. The results of CAP test on Gelatinous Zooplankton assemblages of the coastal and estuarine waters of Bushehr, two stations of Shif Creek- estuary  and Sea station, showed a different and discriminated dispersion pattern, Eutima gegenbaueri, Elrene viridula and Diphyes chamissonis  were determined as indicator species of Sea waters/station, and Pleurobrachia pileus  were identified as indicator/ discriminating species of Shif Creek- estuary. Finally, the results of SIMPER from BEST/BIOENV analysis proved that the dispersion of all identified species were affected by the depth of sampling station, salinity and temperature as the most important factors.

After the world war and the emergence of international organizations in the field of the international system, the world witnessed a change in the arrangement of international actors. One of these international organizations was the International Maritime Organization (IMO). It operates as a specialized agency of the United Nations in the field of maritime affairs and related matters. On the other hand, the Convention on the Law of the Sea, adopted in 1982, is the most important document in the field of the law of the sea that has been ratified so far and plays the role of a reference. This research seeks to analyze and explain the level of relations between emo and the Convention on the Law of the Sea.

The descriptive-inductive method has been selected as the dominant method in this paper and the library method and filing tools have been used to collect data. Therefore, for this research, the historical description of the two institutions, the Imo and the Convention on the Law of the Sea, and then the common features between these two institutions and determining and explaining the level of their relations in the field of international law are discussed.

 This convention refers in various articles to the competent international organization, which means emo. Of course, Emo's name is only explicitly mentioned once in Annex VIII of the Convention. Also, the type of emo relations with the Convention on the Law of the Sea is divided into two categories: functional and thematic. In the functional dimension; The Convention on the Law of the Sea identifies Emo as a competent body, the drafter and source of international laws and standards, and ultimately the supporter and facilitator of the implementation of laws and regulations. In the thematic dimension, the fields of joint work of these two international organizations in the fields of maritime safety, maritime security, marine environment and civil liability due to marine pollution are defined.

The Convention on the Law of the Sea has a framework role and generally addresses maritime issues, leaving the role of legislator in these matters to IMO as the competent international organization. As a result, according to the plausible roles mentioned in some articles of the Convention on the Law of the Sea, as well as in accordance with the fields of activity contained in the Articles of Association, its organizational structure and documents issued in the fields of maritime safety, maritime security, marine environment. And has formulated and approved civil liability for marine pollution.

Chemical storage of water cannot provide complete information about the extent of bioavailability of metals in the environment, while the study of this storage in the chain of water, sediment and macrobenthos can make the rate of rotation and storage risk more visible in ecosystems. Hur Al-Azim wetland is located in the west of Khuzestan Province. Large parts of it have dried up due to the development of Azadegan oil field and the spread of heavy metal pollution in its environment, which can provide serious risks to this ecosystem and the people around it. Therefore, the present study aimed to evaluate the concentrations of heavy metals cadmium, nickel, lead and vanadium in water, sediments and macrobenthos of Hur Al-Azim wetland, as a region with high oil activity.

This study was conducted in winter 2017 to investigate the concentrations of heavy metals cadmium, nickel, lead and vanadium in 8 stations in Hur Al-Azim wetland. The statistical population for measuring heavy metals with three replications included 24 water samples, 24 sediment samples and 24 macrobenthos samples. Among them, the species in macrobenthos samples were identified after washing in a 0.5-micron sieve. After digestion of the samples, the concentration of the elements was measured by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) model Vista Pro Axial. Comparison of heavy metal data from water and sediment samples was performed using SPSS23 software. Shapiro-Wilk test was also used to investigate the normal distribution of results. One-way analysis of variance was used for general comparisons and Tukey test was used for multiple comparisons and differences were significant at 95% level.

The concentration of heavy metals in sediments was higher than that of water and macrobenthos, While the concentration of these metals in macrobenthos was higher compared to water (P <0.05). Heavy metals had the lowest concentration in station 1 (Chazabeh) as a station without oil activity and the highest level in station 4 (between pad 3 to pad 12) as a station with high oil activity (P <0.05). Pad 3 to Pad 12, along with Pad 9 to Pad 12, had the highest enrichment index for all metals. The lowest index of nickel, vanadium and cadmium enrichment index was measured in Chazabeh station and the lowest level of lead enrichment index was measured in Shatt Ali station. Regarding the index of heavy metal pollution factor, the distance station of Pad 3 to Pad 12 with values ​​of 4, 1.16, 0.86 and 3.41 for cadmium, nickel, lead and vanadium had the highest value of this index. Also, Chazabeh station with values ​​of 3.25, 0.18 and 0.54 for cadmium, nickel and vanadium metals and Shatt Ali station with values ​​of 0.58 for lead metal showed the lowest value of this index. The distance between Pad 3 and Pad 12 with a value of 1.92 also had the highest PLI index. In the studied stations in Hur Al-Azim wetland, 10 macrobenthos families (Valvatidae, Vnionidae, Thiaridae, Hydrobiidae, Physidae, Chironomidae, Ceratopogonidae, Sinmuliidae, Gomphidae and Tipulidae) and 11 genera were identified. Among them, Chadabeh station with 43.8 showed the highest bio-index of BMWP and with 4.86 the highest bio-index of ASPT.

Finally, it was found that due to the continuation of oil extraction activities and discharge of toxic pollutants into Hur Al-Azim wetland, there is great potential for rapid and cumulative increase in the concentration of metals, especially vanadium and cadmium and their crossing the critical limit. Indicators for measuring the severity of sediment pollution showed the station between Pad 3 and Pad 12 as the most polluted station in Hur al-Azim wetland compared to Chazabeh station. The correlation between the concentration of heavy metals in sediment and macrobenthos, in addition to emphasizing the uptake and transport of metals along the food chain, showed that macrobenthos can be used as the best biological indicators.

Today, the removal of heavy metals from industrial effluents is significantly increasing, which can play an important role in protecting the environment and human health. In recent years, researchers have resorted to biological methods, especially biological and microbial methods to remove toxic heavy metals. Biosorption of heavy metals is a relatively new technology for the treatment of industrial effluents, and its purpose is to remove toxic metals and clean the environment, as well as recycle precious metals. This process is a rapid reaction between the metal and the cell surface (extracellular bonding) in which the metal adheres to the surface of molecules like a surface protein. Conventional biological processes in the biological purification of metals are biosorption, bioaccumulation and bio-sedimentation. In the present study, sprulina platensis ability to absorb heavy metal lead from aqueous solutions was investigated by optimizing the absorption conditions for live spirulina microalgae. The aim of the present study is to provide a solution for biological removal of lead heavy metal using biosorption method using spirulina microalgae.

Three parameters of algae concentration (0.5, 1, 1.5 and 2 g/l), lead concentration (20, 40 and 60 mg/l) and contact time (30, 60, 90, 180 and 360 minutes) was considered.as experimental parameters. In order to perform the tests, 12 culture samples were placed. By examining the growth rate and after the cultures reached the desired concentration, three concentrations of lead were added to the samples and after certain periods of time, the culture was sampled and the adsorption rate was measured. The adsorption isotherm was then plotted to determine the theoretical capacity of the contaminant absorption.

The results showed that the optimum growth occurred in light conditions of 3000 lux and pH 10 and the maximum optical density was 1.421. The results showed that higher concentrations of algae had a higher rate of biosorption and the maximum absorption efficiency was obtained at a concentration of 2 g/l spirulina. Examination of contact time effect shows that by increasing contact time up to 180 minutes, the amount of biosorption increases and then decreases, which is probably due to the toxicity of the remaining heavy metal on spirulina microalgae cells. The maximum removal of heavy metal was 81.33% and occurred at a concentration of 2 g/l spirulina and a dose of 20 mg/l lead in a contact time of 180 minutes. The results showed that the Langmuir isotherm could fit the experimental data better than other models.

The process of biological adsorption by spirulina consists of two stages of rapid absorption (first 20 minutes) and slow absorption thereafter. The absorption efficiency is upward for about 60 minutes and then gradually decreases. Also, the high absorption rate in the first 30 minutes (more than 50% of the total biological absorption in all samples) indicates the existence of a rapid absorption phase in the first minutes. The reason for the rapid absorption in the first 30 minutes is due to the rapid physical adsorption at the active sites of the algal cell, known as the negative sites, and the adsorption occurs by electrostatic force.

Antarctica, the fifth continent on the planet, is a vast region near the South Pole that plays a role like a beating heart in the rhythm of Earth's life by controlling thermal balance and developing the ocean-atmospheric systems. This continent has singular importance in various scientific, political, and economic aspects, which has attracted the attention of different countries. The extreme atmospheric and oceanic phenomena of this area have an effect on the earth's climate. One of the significant extreme phenomena is mesoscale cyclones. These cyclones convert to polar lows in the special conditions that make modeling and forecasting conditions more difficult. In this research, wind field anomalies are evaluated using satellite scatterometery and reanalysis data in the period from 2000-2020. Different parts of Antarctica have been investigated for the formation of mesoscale cyclones and then presented with polar lows in the study area. 

The Antarctic region has a vital role in controlling the temperature and the climate of our planet. Due to the geographical conditions of Antarctica, various cyclones are formed in this region, and they not only have an effect on the region's climate but also play a determinant role in the earth’s climate. Meso-scale cyclones that have a diameter of less than 2000 km and surface winds stronger than 14 m/s as a result of the main fronts at the poles are classified as polar lows. To investigate this issue, the surface wind data of the National Center for Atmospheric Research (NCEP/NCAR) used a 0.25 degree mesh grid. Then, an anomaly of surface wind is extracted using the Empirical Orthogonal Functions. In the following, different identified polar lows were investigated using the surface wind of satellite scattometry, the temperature of the surface of 500 hp and the polar low life stability obtained from the ERA5 post-processing data set. The cyclone tracking algorithm was used to check all the characteristics of meso-scale cyclones.

Analyzing the anomaly using empirical orthogonal functions shows that the first component represents about 51% of the total surface wind variance. This component has a stronger anomaly pattern in winter seasons than in summer, and this component indicates the dominant wind pattern of the region, and extreme variance is observed in the west of Antarctica. Also, this component shows that in the dry part of the region, the wind anomaly is higher than in the water part, this can happen because of the structure of the Antarctic basin. In the blue part of the study area, on the Amundsen Sea, which is located along the South Pacific Ocean in the west of Antarctica, the wind anomaly is estimated to be higher than other blue areas of Antarctica. This pattern can be caused by hot and cold water currents in the region, which needs serious study and investigation. The second component of the surface wind anomaly accounts for about 20% of the total variance. It shows the highest anomaly in the Weddell Sea. In this region, the Weddell Gyre is dominant and can be caused by the atmosphere-ocean interaction and the atmospheric systems ruling over the region. The third and fourth anomaly components each show about 10% of the total variance. The third component is the most anomaly in Ross Sea and Ross Ice Shelf and the fourth component shows the most changes in Weddelle Sea in addition to Ross Sea and Ross Ice Shelf. Accordingly, Ross Gyre and Weddell Gyre play a significant role in determining the Antarctic wind pattern. According to the criteria provided for identifying mesoscale gyres, polar low pressures can be identified and investigated using satellite spectrometric data and reanalysis.

Extreme weather in high latitudes and near the north and south poles of the earth causes air-sea interaction to happen. The strong winds of these regions generate rogue waves in the oceans. Among these phenomena, there are a series of meso-scale phenomena such as polar lows, with limited information. Therefore, such phenomena are not considered in global models and post-processed data. Consequently, it is necessary to modify the global dynamic ocean-atmospheric models in the Southern Ocean by considering different polar lows.

Background and Theoretical Foundations:

 Approximately 7% of the total land area consists of islands that are arched, rectangular, triangular and quasi-geometric patterns in various water zones. A few of these islands are divided into groups, forming the "archipelago between the oceans" and the "archipelago countries", and this diversity has led geographers to consider each group of islands as a unique combination. The rules of the seas and oceans have played a very important role in ensuring maritime security and order for centuries, but today, thanks to military, scientific and legal development, the need to conceptualize and explain new concepts governing the law of the sea is increasingly felt. The exercise of state authority over maritime areas has long been a vital and crucial issue, and the principle of territorial jurisdiction in domestic territory is an accepted concept in customary international law, but the rules of customary international law in the field of seas are not effective enough to realize the rights of archipelago countries. These customary rules did not provide sufficient practical and legal guarantees for the Algerian governments to access mineral resources, energy fields and fisheries.While delimiting the maritime borders subject to the drawing of "lines of origin" is necessary to determine the width of the "territorial sea" and other maritime regions, the drawing of the lines of origin of the Algerian countries was associated with more challenges. Finally, the 1982 Convention on the Law of the Sea responded to the doubts and, while presenting the definition of the country of the Algerian Assembly, allowed the drawing of the line of origin of the Algerian Assembly if the legal conditions are met in such countries. Now the question arises, how did the efforts of the Algerian countries to realize the rights of fraud in the waters of the Algerian waters pave the way for the drafting of the fourth chapter of the 1982 Convention on the Law of the Sea? And to what extent has the practice of the Algerian states in drawing the lines of origin followed the rules of the Convention?

This descriptive-analytical study, after an overview of the types of baselines, has discussed the possibility of drawing the baseline of the Algerian archipelago or the right to maintain and establish these lines with reference to the 1982 Convention on the Law of the Sea.

The findings of this study indicate that the identification of the legal status of the Algerian countries since 1920 has been the subject of intensive studies in the field of territorial waters. However, prior to the ruling of the International Court of Justice in the Fisheries case of England / Norway (1951), the drawing of the baselines of such countries was in a state of ambiguity. Given that it is possible to determine the width of maritime zones by describing how to draw baselines, the legal challenges of the archipelago countries to delineate baselines, delimit maritime zones and control inter-island waters continued until the 1982 Convention on the Law of the Sea. The Articles 46 and 47 of the 1982 Convention on the Law of the Sea, while defining the concept of the archipelago and explaining how to draw the lines of origin of the archipelago, put an end to years of confusion for international law.

This study examines among the many ambiguous factors that the Algerian country can face and concludes that the issues of how to draw the baseline are more controversial than any other topic, because baselines are the starting point for measuring maritime boundaries and determining The boundaries of overlapping areas with neighboring and neighboring countries. Of course, the legislative silence prior to the 1982 Convention on the Law of the Sea and the lack of a special solution for the Algerian archipelago never prevented them from applying a similar procedure relying on the International Court of Justice in the England / Norway (1951) fisheries case and connecting their islands to direct lines of origin. And to abandon the claim of the need to pass special rules for the drawing of baselines for island territories. However, Article 47 of the Convention sets out a set of objective rules for delineating the archipelago, two of which have a numerical approach (water-to-land ratio / maximum length of baseline) to prevent arbitrary procedures in countries such as the United Kingdom and Australia. And Cuba is legislated for the increasing development of maritime space. Paragraphs 3, 4, 5 of Article 47, with a qualitative approach, indicate the need to observe the conditions for drawing a direct line of origin in drawing the starting line of the Algerian Assembly. The legal status of the countries of the Algerian Assembly. Therefore, the 1982 Convention, according to Articles 46 and 47, was able to provide a correct definition of the concept of the archipelago, how to draw the lines of origin of the archipelago, and finally this study concluded that the possibility of drawing the line of origin of the archipelago or the right to preserve and establish these lines Relying on the 1982 Convention on the Law of the Sea is enforceable, and a study of the practice of the Algerian States has shown that all Algerian States have so far drawn their lines of origin in accordance with the provisions of Article 47.

In order to eliminate deprivation in the southern coastal areas of the country, the construction of small public breakwaters began in 2010. In Qeshm county, which is considered to be the largest island in the Persian Gulf, six breakwaters of Shahid Zakeri, Rigoo, Sooza, Masan, Shibderaz and Kandallo have been constructed as part of this national project. Considering that one of the main goals of the construction of breakwaters has been to eliminate deprivation and improve the social status of coastal residents, in this study, the socio-economic effects of the construction of breakwaters in Qeshm Island have been studied. In this regard, first, indicators related to the construction of breakwaters were extracted in four aspects: "socioeconomic", "physical", "environmental" and "institutional". In the next step, using the cross-impact analysis and MICMAC software, the influenced indicators from the breakwaters were determined. These indicators included "migration", "job creation", "safety and security", "stakeholder satisfaction", "dependency on breakwater" and "investment security" all related to the socioeconomic aspect. In the final stage, information related to the mentioned indicators were collected through site visits, interviews with stakeholders and local residents, as well as general population and housing census data and statistical yearbooks of Hormozgan province. Data processing has been done using the analysis of covariance and content analysis. According to the results, Shahid Zakeri breakwater has a positive effect on all indicators. Shibderaz and Kandallo breakwaters, despite having a positive effect on all studied indicators, have not played a significant role in attracting immigrants to the region. The Sooza, Rigoo, and Masan breakwaters have improved safety, security, and stakeholder satisfaction, but have failed in job creation and migrants attraction.

Identifying shallow water masses is much more complex than deep water; because physical and chemical changes in shallow water occur faster and the properties of the water mass are lost. Since in the absence of air-sea interaction, water masses have different properties, so in this study, due to temperature and salinity conservation, the properties of Persian Gulf water mass are identified. One of the main characteristics of the Persian Gulf is its very shallow depth with an average depth of 35 meters. The maximum depth is located in the Strait of Hormuz with a depth of about 100 meters. The Strait of Hormuz is located in the northwestern part of the Indian Ocean and is the junction of the Persian Gulf with the Sea of Oman.

In this research, a 3D open source ocean model FVCOM in 20 layers was used to model the water exchange between the Persian Gulf and Sea of Oman (47˚E to 59.45˚E and 22˚N to 32˚N) without considering the wind stress on the region, the flow pattern of Persian and Oman Gulfs and the water mass of Persian Gulf in the four seasons of spring, summer, fall and winter should be studied. FVCOM uses the finite volume method to discretize hydrodynamic equations in a triangular grid. Specialized SMS software version 10 was used to generate the computational network. A non-uniform computational network with a horizontal resolution of at least 950 m to 4700 m was used in the model and the bathymetery information was interpolated with 30-second accuracy from the GEBCO-2019 data on this network. Water level fluctuations on open boundaries correspond to the location of the open boundary nodes of the computational network located at 59.45˚E, which was extracted from the TMD and entered as the main configuration of the model. Temperatures and salinities profiles of open boundaries from HYCOM model output (freely available) were also used at standard depths. The model was run in the absence of air-sea interaction and the role of wind stress for 6 years. HYCOM and satellite data were used to calibrate and validate the model, respectively.

The saline waters of the Persian Gulf to the mouth of the Strait of Hormuz are well visible in the surface layers and are not seen in the surface layers from the mouth of the Persian Gulf to the Sea of Oman. In the middle layers of the Oman Sea, there are waters with the characteristics of the waters of the Persian Gulf, which can be concluded that the surface waters that existed in the west of the Strait of Hormuz have been transferred to the lower or middle layers and flowed to the Oman Sea. Considering the temperature and salinity conservation in the water mass, the temperature and salinity of the Persian Gulf in the Strait of Hormuz were studied and the results show that the Persian Gulf water mass (38psu) in the summer season through the south of the Strait of Hormuz as a subsurface flow and in the winter season this water mass penetrates to greater depths and moves further away from the Strait of Hormuz. The Persian Gulf water mass exits through the southern part of the Strait of Hormuz as a subsurface flow. In the summer season, there is a water mass with 37psu salinity in the depth range of 50 to 80 meters and 40 km off the coast of Oman, whose exact position is latitude 25.4˚N and longitude is 56.50˚E to 56.69˚E and in the cold season, it moves away from this area and advances to lengths greater than 57˚E and penetrates to a depth of about 130 to 150 meters and more depths.

Due to the high rate of evaporation in the Persian Gulf, to replace the evaporated waters of the Persian Gulf, it is necessary for water to enter the Persian Gulf from the Strait of Hormuz. The salinity results of summer show this phenomenon well and the water entering the Persian Gulf is diverted to the coast of Iran and the movement of these waters from the coast of Iran to the northwest of the Persian Gulf continues. There are years, but it is more intense in summer than in other seasons.

The purpose of  this study is to evaluate the oral comparison of chitosan with galic acid Balikiti of typical carp dice films during the preparationof the  refrigeration. Fish fillets were immersed in three groups including 1) control treatment 2) chitosan solution 3) chitosan + gallic acid. Microbial tests including counting aerobic mesophilic bacteria and cryophilic bacteria were performed by purplate method on agar pellet culture medium. Chemical properties including measurement of thiobarbituric acid by spectrophotometry, evaluation of volatile nitrogen compounds by calderal method, free fatty acids by titration method, pH measurement, colorimetric and sensory evaluation of samples by hedonic method were performed by 15 trained evaluators. will be. Comparison of microbial load of aerobic and cryophilic mesophilic bacteria in control sample and different treatments showed that the highest bacterial load related to control sample and mesophilic bacterial load in coated samples were significantly lower than control (P ‹0.05). The amount of bacterial load in the coated samples did not show a significant difference at the end of the storage period (P ‹0.05). Examination of physicochemical factors during the 12-day storage period showed that all coated treatments Significantly (p <0.05) had lower values. The results of sensory evaluation showed that the combination of chitosan and gallic acid can improve the sensory quality of common carp. Overall, the results showed that the use of biopolymers with natural antioxidant and antimicrobial compounds improves the microbiological load, delays oxidative spoilage and increases the shelf life of common carp.