فصلنامه اقیانوس شناسی
پیاپی 49 (بهار 1401)

 Transportation is one of the necessities for the economic development of any country. Among various modes of transportation such as air, land and sea the sea transportation is the cheapest, and it is more important as the worlds continue to grow. In Iran, due to political issues and sanctions, and since imposing limitation on marine transport cannot be implemented in international law, sea transport has become more important than land and air.

In this study, value-added factors in the development of the maritime transport industry are identified. To identify the role that different factors play in the final value created, the criteria of service, cost quality, and time, using the Johansson model are used, as well as the multi-criteria utility method (MAUT) to evaluate and compare the value of different processes.

The application of the multi-criteria utility method is illustrated with an example from each industry sector, namely liners, bulk carriers, tankers and specialized loads.

The results showed that the most important factor by transport companies is the emphasis on quality. There is also a different importance on services and costs in different parts of the industry and the time criterion is considered as the least valuable factor by all four parts of the companies surveyed

Different types of instability occur at sea. Layered structures are one of the most important physical phenomena in marine environments. Static stability and double diffusion are associated with density changes with respect to depth and temperature and salinity gradients, respectively. Due to the difference in temperature and salinity in the water column, marine areas are inherently capable of double diffusion convection. Their study is important because of the effect they have on some oceanic processes (including: changing water stratification, the formation of internal waves, the speed of sound) and even on marine life. In this research, the static stability and double diffusion of the waters of the Caspian coast are investigated.

In this research, field data of temperature, salinity and density of coastal areas of Mazandaran from Ramsar to Babolsar have been used. Measurements were taken in summer (July and August) and late autumn (December). Temperature and salinity parameters directly from field measurements and other parameters (density, buoyancy frequency, density ratio and turner angle, etc.) using temperature and salinity data and related relationships by Excel program ( Excel) is calculated. The profiles of temperature, salinity, density, buoyancy frequency and turner angles in the hot and cold seasons have been studied and compared.

Salinity inversion In most stations that have occurred, the thickness of the inversion layer varies from 3 to 10 meters. Most salinity changes in the inversion layer of about 0.5 psu occurred in summer. In the cold season, salinity inversion occurs at lower depths than in the warm season, which can be due to changes in the external factors of the Caspian Sea, including evaporation and rainfall. Also, slight temperature inversion was observed only in two stations with a thickness of 1.5 m and 3 m with temperature changes of 0.3 and 0.7 ° C, respectively. Due to the short range of salinity changes, density changes are mainly affected by temperature. The density ratio in salinity inversion stations is often negative, ie double diffusion convection has not occurred. However, in some stations, especially in the eastern part of the study area, the density ratio is positive and greater than 1, which indicates the occurrence of the phenomenon of double diffusion convection of the weak finger regime.

In the Mazandaran beach, due to the absence of inpatient complications, including Absheron, no specific temperature inversion has been observed. The density ratio in these areas is often negative, indicating stability in the water column. In the eastern part of the study area, a larger buoyancy frequency was recorded, which shows greater stability in this area. In deep layers, however, the buoyancy frequency tends to be zero (neutral stability). Also, the diffusive regime was not observed in the studied stations, but in the east of the research area, the finger regime occurred in several stations.

  In recent years, due to the strategic importance of Makran coastal zone and new economic approaches for this region, eastern coasts have been identified as development points in the country’s geography and Jask port is turned to be one the most suitable points for economic and commercial activities in this region. In the present paper, the strengths, weaknesses, threats and opportunities of Jask port as one of the important ports in south western part of Makran coastline have been identified.

  This research has been done in two stages. In the first stage, internal and external factors affecting Jask port have been identified and the SWOT matrix has been formed. Then, in the second stage, according to the results of the evaluation matrix, the strategic orientation of the port is determined.

  The strategic orientation is found to be aggressive meaning that the strategic plans made by the decision makers should be based upon the identified strengths and opportunities of the port.

 Based on the SWOT analysis and the strategic orientation obtained for Jask port, development  of the port and various operational potentials are viable. Changing the port management model and inviting the private sector to invest in the port can lead to the port performance improvement

In this study, the deposits of the upper part of Pabdeh Formation-lower part of Asmari Formation in the stratigraphic section of Nareh with a thickness of about 236 m located in the southwest of Jahrom were studied.In the lower part of the sequence, the deposits of the upper part of Pabdeh Formation are composed of shale and interlayers of argillaceous limestone with a thickness of about 154 m. Following that, the deposits of the lower part of Asmari Formation with a thickness of about 82 m of argillaceous limestone and medium bed limestone are located. From this section, 104 samples including 68 samples from the upper part of Pabdeh Formation and 36 samples from the lower part of Asmari Formation with 1 m intervals were collected.

By preparing 104 samples of the studied sequence and preparing it by slide smear method, 33 species belonging to 16 genera from the fossil group of calcareous nanofossils were identified. The slide smear method is a quick and easy method in which nanofossils are not wasted.

Based on biological events and associated fossil assemblages, the bio-zones of Sphenolithus pseudoradians Zone (NP20), Ericsonia subdisticha Zone (NP21), Helicosphaera reticulata Zone (NP22), Sphenolithus predistentus Zone (NP23) were identified in the study sequence. The zones studied are consistent with zones CNE20, CNE21, CNO1, CNO2- CNO3 / CNO4 of Agnini et al., (2014) and zones CP15b, CP16a, CP16b, CP16c -CP17 / CP18 of Okada and Bukry (1980).

Based on the introduced bio-zones, the age of the upper part of Pabdeh Formation in the studied section of Late Eocene (Priabonian)- early Oligocene (early Rupelian) and the age of the lower part of Asmari Formation of early Oligocene (late Rupelian) are suggested. According to the present study in Nareh section, the boundary between Pabdeh Formation and Asmari Formation is continuous.

 According to the Convention on the Law of the Sea, if the continental margin along the land area of ​​the coastal state exceeds 200 nautical miles, it is possible to delimit the outer continental shelf for the coastal country and in this regard, important ‌The best result of delimiting the continental shelf beyond 200 nautical miles is the identification of an opaque maritime territory called the Gray Zone, a practical example of which has been realized in the Bay of Bengal cases. Considering that the determination of the extent and external boundaries of the territory of the maritime regions is one of the main objectives of the international law of the seas in the present age and based on the national jurisdiction of the coastal government of maritime regions such as inland waters, territorial sea, waters of the archipelago, strait International, adjacent, exclusive economic zone and continental shelf under national jurisdiction and the high seas, coastal areas, ocean floor and seabed beyond national jurisdiction, and exclusive economic zones and continental shelf beyond Territorial sovereignty and national jurisdiction of the coastal state. Also, given that sovereign rights in these two maritime regions are inherently limited to the same regions, it is important to delimit their fair limits, and therefore the large number of cases before the International Court of Justice and arbitral tribunals confirms this fact. During the last few decades, the continental shelf has been one of the most controversial maritime areas for delimitation between coastal countries. Given these issues, the question now arises as to whether a particular customary or legal rule is followed in delimiting the continental shelf beyond 200 miles. And how can the obligations and fraudulent rights of the coastal government in the gray area be analyzed?

This research is a descriptive-analytical review of important cases and the decision-making of judicial and arbitral authorities such as the International Court of the Law of the Sea and the Court of Arbitration in these cases.

The findings of this study indicate that after years, the ruling of the International Court of the Law of the Sea in the Bangladesh / Myanmar case and the ruling of the Arbitration Court in the Bangladesh / India case to the maritime disputes of the coastal neighbors in the watershed The Bay of Bengal ended by accepting the authority to determine the continental shelf beyond 200 nautical miles. However, the delimitation of the continental shelf beyond 200 nautical miles created a gray area, which Professor Kelson did not consider effective in identifying the rights and duties of the coastal state in the case of John Maine Bay, and refused to accept it as an unusual condition. However, the conflict of interest in the gray area of ​​the Bay of Bengal, which stems from the simultaneous exercise of jurisdiction in the exclusive economic zone beyond the continental shelf, calls for immediate legal normalization to make better use of the resources of this special maritime zone in the near future. Pre-disclosures are expected to increase beyond 200 nautical miles after the success of judicial and arbitral awards in the Bay of Bengal, which means more small and large gray areas in other parts of the world.

This article examines the judicial and arbitral awards issued in the Bay of Bengal watershed and concludes that the International Court of Maritime Law and the Arbitration Court, while accepting the jurisdiction of the coastal state to delimit the continental shelf beyond 200 nautical miles, apply a justice approach. The three-stage reform, adhering to the procedure of delimiting the continental shelf, made the realization of the gray area in these conditions inevitable. However, overcoming potential legal conflicts such as maritime issues, marine research and environmental issues in the region can only be resolved through future bilateral agreements.

 Fishery is one of the fastest-growing food sectors throughout the world. The increasing demand for products creates massive fishing pressure on natural stock, especially in the open-water ecosystem. Fish are now considered as assess the life history traits i.e. growth, reproductive characteristic, recruitment pattern and mortality to ensure sustainable management for conserving the wild stock. Growth pattern help explain how populations behave under different environmental conditions. The basic purpose of fish stock assessment is to provide advice on the optimum exploitation of aquatic living resources such as fish. Living resources are limited but renewable, and fish stock assessment may be described as the research for the exploitation level which in the long run gives the maximum yield in weight from the fishery.  Length-frequency distribution is an important biometric index to assess the dynamic population of fish. The purpose of this paper is to describe the growth pattern, growth parameters and mortality of P.argenteus in the north of the Persian Gulf.

In this study, considering a panmictic population for stock of P. argenteus in the Persian Gulf, on a monthly basis from April 2017 to April 2019, 4,236 samples were bio-assayed. The growth of the fish was assumed to follow the von Bertalanffy’s growth function. To calculate natural mortality, Pauly empirical was used. The total mortality rate (Z) was estimated using length converted catch curve method. The fishing mortality has been calculated from M and Z as F= Z-M.

The mean and standard deviation of the fork length of the P. argenteus population in the whole period was 23.48 ± 1.19 cm. The coefficients of the relationship between length and weight for index (b) were equal to 2.95 and index (a) was equal to 0.048. The amount of growth parameters estimated by Shepherd and ELEFAN methods for infinite length is 417 and 418 mm, growth coefficient of 0.43 and 0.47 per year and t0= -0.32 and -0.25 per year were estimated. The growth standard index (Ǿ) was calculated to be 2.87 and 2.91, respectively. Using the inverse Bertalanffy equation based on the results of Shepherd and ELEFAN, 8 and 7 age groups were estimated in the capture composition, respectively. Total mortality was estimated at 4.83 per year and natural mortality at 0.87 per year.

The results of growth and mortality parameters showed that the stock of P.argenteus are under fishing pressure and for fisheries management of this stock, the data of all stations should be used.

The processing of the measured passive magnetic signal instigated from remote ships and submarines is one of the most effective and novel methods for the detection of remote traveling vessels. The geomagnetic field of the earth, the electrical conductivity of seawater, and the electromagnetic induction law are the three elements helping us to detect remote vessels in seawater. The traveling of a vessel in the seawater as an electrical conductor induces magnetic anomaly in the geomagnetic field of the earth whose processing and detection leads to the detection of the remote vessel.

In this paper, we present a mathematical structure for modeling the magnetic anomaly and its relation to the environmental parameters as well as the physical parameters of the traveling body such the vessel’s shape and speed. We propose the detection process through a single magnetic sensor located at some specified depth under the sea surface. The proposed structure has many advantages to the currently available airborne sensors.

We will analytically show that there always exists an optimal depth wherein if the magnetic sensor is located, maximum detection probability is achieved. We will show through numerical results that the optimal depth gets higher if the travelling speed of the vessel is increased. We will also show that if the traveling speed is lower than 10m/s, the optimal depth is lower than 6m and is independent of the sea depth

We will show that the amplitude of the magnetic wake above the sea surface and under the seabed suffers from severe attenuation, and there always exists an optimal depth under the sea surface wherein if the sensor is positioned, maximum magnitude of anomaly is captured. The impact of different parameters such as the location of the sensor, the depth of the sea, as well as the speed, length and traveling depth of the submerged traveling body are evaluated on the performance of our proposed scheme.

Geostrophic currents profoundly influence various oceanographic events and different interactive processes between the atmosphere and the ocean. According to satellite images, eddies of Persian Gulf with an average diameter of 40-90 km and a speed of 3-6 cm/s, have been observed mostly near the coasts of Bushehr and the central part of the Persian Gulf. Hence, by the purpose of numerical solution, a geostrophic eddy current is dissolved in one layer fluid model called the shallow water model.

The present study uses numerical solutions for geostrophic equations provided by the Woods Hole Oceanographic Institution, entitled "Coriolis Guide" by James F. Price and is available in four separate sections for free research studies. It can cover basic equations based on the Coriolis force (such as the geostrophic equations). Using dynamic realities such as ocean shallowness, hydrostatic approximation, and the relatively constant nature of the vertical structure of the ocean, a geostrophic eddy is solved in MATLAB software based on the geostrophic equations. The origin of the coordinate system is on the center of the eddy and the results are plotted along the diameter of the eddy. The Coriolis parameter, f, is constant (f-plane coordinate system) and the friction is ignored. In this numerical solution, the finite difference numerical method has been used and the model development has been done on a structured grid and regular rectangular shape. The studies have been performed at latitude 28˚N (similar to the Persian Gulf) for a geostrophic eddy with a width of 50 km and a peak height of 3 m relative to its sides. In this numerical solution, the eddy properties of the Persian Gulf are tested as much as possible. The simulation is performed as a dense layer of fluid with a rectangular peak for 10 days from the initial time of zero and from a standstill (initial velocity of zero in the center of the peak). The energy source for the eddy activity is provided by the potential energy stored in the initial stationary state of the fluid package. Therefore, the total energy is stored in this shallow water model.

The Rossby deformation radius was 28.5 km and eddy velocity was 0.029 m/s, which was in good agreement with the satellite images of previous studies. The results show that due to the approximation of the geostrophic current, the resulting eddy shape is symmetrical and Gaussian. The eddy peak begins to fall by the release of the initial rectangular peak, at zero time for a few seconds under gravity at the beginning of the simulation, and it releases potential energy and produces a current. The current moves at a constant speed in the eddy. Moreover, at the beginning of the simulation, many instabilities are observed on the water surface and around the main geostrophic ring, which as the end of the simulation approaches, these pulses almost disappear and only the main geostrophic ring of eddy remains relatively stable. In addition, the initial rectangular eddy becomes a soft curved eddy. The results show well the two opposite directions of (horizontal components of) velocities at the right and left of the center of the geostrophic eddy. By shifting along the current due to the right and left of the geostrophic eddy ring relative to its center, a vortex is created that creates rotation for a balanced geostrophic eddy. Kinetic energy and potential energy will be equal on the last day of the simulation when the model reaches a steady state and perturbations on the basin surface disappear.

From the results, it can be clearly seen that the Coriolis force and gravity lead to an eddy with a geostrophic equilibrium. By changing the vertical intensity of the fluid column strength, the rotation speed of the eddy also changes, and the larger eddy diameters have more energy.

 The Indian Ocean has come to the attention of major global and regional powers in recent years due to its geopolitical position, strategic straits and waterways, its transport role, and its strategic and economic importance. On the other hand, in order to become a world power, China seeks an active presence in the open waters and strategic ports of the world. The country is implementing a plan to revitalize the Silk Road as a one-way belt initiative, which has various strategic, geopolitical, political, economic and security dimensions. This project has two routes, sea and sea. The project's sea route, called the 21st Century Sea Silk Road, connects to the port of Venice in Europe after crossing the Indian Ocean. Another emerging regional power is India, which is seeking to increase its geopolitical influence in the subcontinent. This descriptive-analytical study examines the strategic and geopolitical rivalry of the "One Belt One Way Belt Project" in the Indian Ocean.

The research method of this research is descriptive-analytical. It is descriptive because it examines the current situation and systematically and systematically describes the current situation of the research subject. It is based on this analysis that in addition to stating the current situation, the reasons for how and why the situation and its dimensions are explained and the strategic and geopolitical competition of the China Ring Road project in the Indian Ocean has been analyzed. The method of collecting information is library and using articles, books, documents and Internet resources is valids.

China and India are both emerging powers in the international system. Although there are different and sometimes contradictory views on the degree of stability and strength of each of them, there can be no doubt that both countries are economically world-class and their continuous economic growth is itself a new condition of behavior. Brings political and strategic. India, on the other hand, will become the world's fourth largest economy in the next few years and will be forced to import energy, 90 percent of which will pass through the Strait of Hormuz. Economic conditions and reliance on the Indian Ocean have led both countries to strengthen their military and naval forces in the Indian Ocean. India has paid close attention to the navy over the past decade and is currently one of the world's largest navies with 155 warships. China is also present in eastern and western India, building a network of naval bases and centers in neighboring countries, from Pakistan to Myanmar. China and India are monitoring each other alongside maritime protection of their economic interests, which are heavily dependent on the Indian Ocean, and there is a slow rivalry between the two, including the Sino-Pakistani alliance against India. In this regard, it is clear that the Sino-Pakistani alliance is a strategic concern for India. In recent years, within the framework of this coalition, China has found an increasing presence in the port of Gwadar. In fact, this port is one of the important areas of the country's presence in the Indian Ocean, and many, especially in India, have talked about the possibility of establishing a Chen military base in this port. However, in the current context, as it is very provocative for India and the United States, it is unlikely that this action will be taken openly by China. In any case, Gwadar is a strategic lever at China's disposal that it can use against India in critical situations. India is also quite concerned about the cooperation between China and Pakistan and is trying to use the Iranian port of Chabahar as a trump card against China.

China is achieving its long-held dream of becoming a world power, and China's success will push the development model out of the monopoly of the West, and another power emerging in the Indian Ocean in the 21st century is India. There are differing views on Sino-Indian relations. Some believe that the deep and long-lasting geopolitical rivalry has shaped relations between the two countries for many years, and that the source of these rivalries is the lands and people that are around or between the two countries. Some have gone so far as to believe that India and China will become dangerous rivals in the near future. Some also believe that any drastic progress in India-China relations is unlikely and that relations between the two will remain competitive, and that despite the deep differences between India and China, the two sides must avoid the escalation of tensions into a public rivalry. To take. But in the meantime, trans-regional actors such as the United States are influencing China-India relations and trying to somehow manage the current developments in the Indian Ocean. The Islamic Republic of Iran, as an Asian country, due to its geopolitical position, is bound to have good relations with Asian countries and powers, and with a brief look at the history of Iran's relations with Asian countries, it can be seen that relations with these countries are always in different dimensions. It has been established at an appropriate level, although at times, due to the political conditions and developments in the region, these relations have had ups and downs. In this regard, the geopolitical position and capabilities of Iran (Chabahar) will have a good ground in various dimensions to influence the relations between India and China and, consequently, the developments in the Indian Ocean. Thus, Iran's role in the power relations between India and China can enhance the understanding of the future international system and facilitate knowledge of future developments in the Indian Ocean for decision-making. Gwadar Port not only as a port Important for Pakistan, but also a port where merchant ships, warships and even Chinese submarines can be stationed. And given that the port is located east of the Strait of Hormuz, Western countries have become very sensitive to this issue, and this is one of the main reasons for Western pressure on Pakistan. The Chinese have signed a $ 5 billion contract in the port of Salameh and Qawin to support the port in eastern Oman. In 2018, the United States of America also signed a contract with Oman in these ports under the pressure of Oman. The Omani, who initially resisted the negotiations, eventually agreed to the deal. China then invested $ 1,900 in the port of Hambantota, which could effectively control both the center and south of the Indian Ocean. Chabahar port, the development contract of which has been signed between Iran and India and is to be developed by this country, and this country is the main axis of its development, is 70 km away from Gwadar port, and these two ports have a common geography and common culture. have. One of these ports, Chabahar, wants to be developed by India, which is an ally of the West, and the port of Gwadar, which is opposed by China, which is opposed by the West, has to some extent followed this path. Under these circumstances, a geopolitical competition will be created in the future, and due to lack of maturity and without examining Iran's geopolitical analysis of issues and concluding a contract with India for the development of Chabahar, not much work has been done by India in this regard. In particular, it is propagandizing that this propaganda has made Pakistan very sensitive because Pakistan opposes the development of the port of Chabahar by its rival, India. On the other hand, it has infiltrated Afghanistan from the north and its government agencies, which is Pakistan's strategic depth. On the other hand, India is located in the east of Lahore, India, and finally in the west of Pakistan, the Indians are active. The Islamic Republic of Iran must act in such a way that the port of Chabahar, as an axis in the bed of the "One Belt - One Way" project, moves in the same way and like the port of Gwadar, and has no other way. And in fact, allow China to be active in this field, and in fact, these two should be considered as a project, and if there are two projects, one is India and the other is China, we will not succeed. On the other hand, due to India's internal problems, the country does not have the capacity to invest in the port of Chabahar because India is not ready to invest abroad. Therefore, the Islamic Republic of Iran must develop Chabahar in the southeast of the country with the help of the Chinese, and this does not mean that India or other countries are not allowed to cooperate. On the other hand, China is ready to create the bed and infrastructure for development in the port. It has Chabahar.

  Fish and sea food are important economic products at many countries. Despite the high nutritional value of seafood products, there is higher perishable against environmental factors and microbial factors and it causes the process of spoilage in the fish to begin immediately after death.Therefore, the aim of this study was to isolate and identify the bacteria in green back gray mullet with abdominal contents under cold storage conditions, in order to reduce and prevent the spoilage process.

 In this study,86 pieces ofIn this study, 86 pieces of green back gray mullet fish with contents inside the abdomen and type of abdominal emptying were freshly prepared from the fish market of Abadan city. Fish and ice samples in a ratio of 1 to 2 (w / w) with ionolite boxes were immediately transferred to a processing laboratory located at Khorramshahr University of Marine Sciences and Technology. For bacterial counting and identification, ice (0%) and refrigeration (4%) were stored for 16 days.

The results showed that the number ofmesophilic, psychrotrophilic, Staphylococcus and H2S producing bacteria counts significantly increased during storage.

  The results of bacterial identification showed that Gram-positive bacteria of greenback grey mullet (Chelonsubviridis) stored at chilling were Micrococcusspp.,Staphylococcus, Listeria spp., Corynebacterium spp., Lactobacillusspp.,Bacillus, Staphylococcus spp. and Gram-negative bacteria of greenback grey mullet (Chelonsubviridis) stored at chilling were Pseudomonas spp., Klebsiellaspp.,Vibrio spp., Enterobacter,Aeromonas, Shigella,Serratia.