فصلنامه اقیانوس شناسی
پیاپی 55 (پاییز 1402)

The Acoustic Tomography (AT) systems are one of the remote sensing technologies to measure flow characteristics in aquatic environments. The only difference between various types of AT systems is the frequency, so that for the ocean class the frequencies ranged from 20 Hz to 1 kHz, for the sea class ranged from 1 kHz to 10 kHz and for the river, dam or lake class ranged from 10 kHz to 60 kHz. The output of this type of system also contains outlier data, just like other acoustic measurement devices. Failure to pay attention to the issue of detection and replacement of outliers causes a decrease in measurement accuracy as well as an inappropriate effect on flow modeling and data assimilation of models. The review of the previous studies shows that the removal of outlier data in this type of system is generally done by the simple method of standard deviation. In the last study, the analysis of the AT data was performed using the three-dimensional Rousseeuw Phase-Space thresholding (3D-RPS) algorithm and compared with the standard deviation method, which indicated its better performance than the simple standard deviation method.

In this study, the Modified Phase-Space Thresholding algorithm (mPST) is applied to AT data and its results are compared with the 3D-RPS method. For this purpose, the data collected in Gono River, Japan has been used, and outliers were identified and replaced with appropriate values using the two mentioned algorithms and five outlier replacement methods. Then, the results were validated with Rating-Curve (RC) data obtained from the hydrometric station of the study area as reference data. Furthermore, in another experiment in the Anzali port, using the mPST algorithm, the analysis of the AT data was performed and the volume of water entering the Caspian Sea was measured.

The results of this research showed that the use of the mPST algorithm has increased the accuracy of the flow measurement in such a way that the relative difference of the flow rate measured with the AT system after applying this method in combination with the average signal replacement methods and The last valid data with flow rate measured by RC method is limited in the range of -15% to +20%. While by applying the 3D-RPS algorithm, this value is in the range of -20% to +30%. The results of the sound recording test of Anzali port also recorded the volume of 200 m3/s flowing to the Caspian Sea.

Since AT data used in the data assimilation of ocean, sea, and river models, it is important to analyze the outlier data of the system and replace it with appropriate data. In this study, an attempt was made to improve the accuracy of the measurement by applying the mPST algorithm to the AT data. The comparison of the output results of different outlier mining methods showed that the mPST method combined with the average signal replacement methods and the last valid data before the detected outlier data has the best performance. As a result, the mPST method is recommended to be applied to AT data.

Background and Theoretical Foundations:

 Today, the progress of a country in terms of infrastructure, facilities, infrastructure and maintenance requires a lot of capital, which alone is beyond the capacity of the government sector. Also, the public and private sectors do not have a lot of capital on their own, so the best solution for providing capital and high specialized ability to carry out large and long-term projects is the partnership of the public sector with the private sector. In ports, the lack of knowledge and management necessary to provide effective and practical solutions for investment is one of the main reasons for infrastructure financing challenges in sea terminals. It is claimed that public-private partnership infrastructure development leads to better performance compared to conventional contracts, but the empirical evidence for this claim is weak. This paper uses investment data of Middle East and African ports from 2004 to 2022 and estimates the impact of different variables on the share of government ownership in terminal infrastructure projects.

This study includes 410 samples from 2004 to 2022. The collected data is categorized based on unique public-private partnership projects in the port. In general, ten factors have been introduced in two groups of institutional quality variables and operating contract variables, which are assumed to be related to the contribution of government intervention in public-private partnership projects in the port. In order to calculate the effect of time and the unique organizational environment of a country, six control variables are presented in this study: government effectiveness index, political stability index, rule of law index, regulatory quality index, economic freedom index and the year of the contract. Since finding the important operational contract and institutional quality factors that affect the share of state ownership in public-private partnership in a port is exploratory in nature, therefore regression is used and since the share of state ownership in public-private partnership in a port is The dependent variable is continuous and the amount of changes in the dependent variable is of particular importance in this study, so as a suitable option, multiple linear regression is used.

This study tries to investigate the effect of operating contract factors and institutional quality on the share of state ownership in a public-private partnership in a port in developing countries. This experimental model includes ten independent variables, four operational contract variables, six institutional quality variables and two control variables. To evaluate the five hypotheses presented, four multiple linear regression models were created and their results were presented. According to the results, all four presented models are very important and can provide more information about the validity of the model.

Findings show that larger sum of public-private investment, a higher historical proportion of state ownership, the existence of both foreign and different types of private investors are all associated with a higher share of state ownership in port public-private projects. Other findings from the study suggest that the presence of tenders, local private investors, and vertical and horizontal integration are negatively correlated with the share of state ownership. Banks are other private investors, terminal operators and state authorities can benefit from this study. Investors can use it as an evaluation framework when deciding on a project appraisal and the state can benefit at the time of deciding when to take responsibility for port public-private partnership projects.

The present research is of a quantitative type that is objective, applied and in terms of nature, heuristic mixed method has been used to collect data. This research has been done in three stages. The first stage was to identify the effective factors in attracting domestic and foreign investors in the free zones, which was achieved through library studies. In the library studies section, specialized internal reports, similar projects done in other countries, and domestic and international articles have been used. Then, in the second stage, a research questionnaire is prepared and distributed among the Delphi group, including 3 experts from the free zone, 1 expert from the Khorramshahr Port Investment Unit, 1 expert from the Abadan Port Investment Unit, and 1 professor from the khorramshahr university of Marine Science and Technology has taken place. The validity of the questionnaire was confirmed by content and face methods and its reliability according to Cronbach's alpha coefficient (0.971). According to the result of Kolmogorov-Smirnov test (abnormal nature of data), chi-square test was used in the inferential section and hierarchical technique was used to prioritize the factors. Findings showed that the Arvand Free Zone in the external dimension of the factors of the ability to transfer money and capital, exchange rate fluctuations and inflation and in the internal dimension of the cost of production in the Arvand Free Zone is associated with problems and weaknesses. The result of the hierarchical technique showed that the size of the local and regional market with a weight score of 0.156 was recognized as the main priority of domestic factors and exchange rate fluctuations with a weight score of 0.136 as the main priority of external factors.

Background and Theoretical Foundations:  

Submarine communication cables currently carry the largest volume of international voice, data and video traffic in the world, and are a key component of telecommunication cyber infrastructure and international information traffic. Data transmission through cable is both cheaper and several times faster than satellite. In land areas, cables are usually protected by owners and national jurisdiction, while protection in the sea, whether physical or legal, is more difficult. Modern submarine cables use fiber optic technology to transmit data at the speed of light. Therefore, the cables that provide this connectivity are part of our critical infrastructure and must be preserved to protect the data governance needed to function in a modern society. Despite such importance, submarine cable systems are vulnerable to various emerging cyber security challenges. International laws that can potentially respond to these challenges have significant gaps regarding the security of such cables in maritime areas. In the legal regime established in the 1982 Convention on the Law of the Sea, this important but invisible subgect. Given that traditional international law is remarkably oblivious to cyber security and its threatening factors, this situation is not surprising. In the meantime, the Tallinn Manual 2.0 on International Law Applicable to Cyber Opreations (hereinafter, Tallinn Manual 2.0 or the Manual) has been able to describe and evaluate the actions taken in the cyberspace in terms of international law with detailed studies conducted by an international group of experts. The only research background that has been written in Persian on this topic is the article entitled "Legal Dimensions of Submarine Communication Cable; From Conflict of Interests to the Ruling Rights of the Coastal State" by Javad Salehi which was published in the Journal of Energy Law Studies. This article is very valuable in terms of evaluating the obligations of the coastal states towards the submarine cables and it is comprehensive and well-deserved. However, in other dimensions related to such cables, and especially from the perspective of evaluating the current international legal system, which is intended in this article, it does not meet the needs of the researcher. Furthermore, it does not address the approach followed by Tallinn Manual 2.0 concerning the protection of submarine communication cables. Taking into accont Tallinn Manual 2.0, Our basic question in this article is whether the current legal regime is sufficient and reliable to ensure the security of the vast network of cables that pass through the ocean floor and thus ensure the security of the world's telecommunication systems?

Employing a descriptive-analytical method, using library resources and referring to the Tallinn Manual 2.0, the authors try to examine the protection of submarine communication cables in the mirror of the Manual.  

  Existing rules are ineffective in a world increasingly defined by network redundancy and interconnectivity, and this is the very point not even addressed in the Tallinn Manual 2.0. Since in the era of technological advancements submarine cables are becoming increasingly important for global infrastructure, the existing regime governing them is reminiscent of an abnormal neglect in international regulation and calls for more intergovernmental cooperation and It is also necessary to review the laws governing the protection of cables.  

 Since in the era of technological advancements submarine cables are becoming increasingly important for global infrastructure, the existing regime governing them is a reminder of abnormal neglect in international regulation and requires more intergovernmental cooperation as well as amendment of the laws governing the protection of cables. Also, unifying the protection of communication cables and preventing damage to the cable at any point requires that any distinctive legal features among the countries that are connected to the same cables be identified and harmonized. In this regard, it is not far-fetched to propose establishement of commissions for the unification of legal rules consisting of legal experts from the member states at regional levels.

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

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

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

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

Although the sovereignty and governance is mainly relate to land, but recently the issue of governance over the seas and oceans are including in the general policy of the governments is considered as a part of the long-term actions and plans of the governments. This governance, at the national and international level, and in addition It also includes the influence of non-governmental actors and non-governmental organizations on the pillars of the government. More than 55% of the earth's surface is covered from seas and oceans, and while according to the United Nations conventions, these seas and oceans do not belong to any country or government, but all the people living on the earth can protect and Take care of these rich resources, and take advantage of them. This means that every Iranian person can benefit from all the resources available in the oceans and open waters. On the other hand, in the definitions of governance, one of the most important tasks of the ruler is to provide maximum benefits for the nation and the country. Therefore, it can be conclud that providing maximum benefits from the oceans and seas is one of the duties of governments. Fortunately, with the special attention of the Supreme Leader and the government to the sea-based economy or the sea as the axis of development, recently the seas have received special attention. However, the question that remains in the mind is whether the government of the Islamic Republic of Iran has a proper structure to manage the country's interests from the surrounding seas, including the Persian Gulf, the Oman Sea, the Caspian Sea, and the oceans and open seas, which are more than 55% of the earth's surface? This research aims to find a suitable model for the oceans governance by examining the existing structures and evaluating the power of these structures in the government of the Islamic Republic of Iran. In comparison with the expected capacity to obtain maximum benefits from the oceans and seas and studying structures with similar tasks in other countries, to propose in the government of the Islamic Republic of Iran. The requirement of integrated management analysis and compliance with international conventions is that this analysis be done at the national and international level. Obviously, there is a need for concentration, interaction, cooperation and leadership for all ministries of a government that have duties or powers related to the use and management of seas and oceans. To achieve this model, this research uses a fundamental study research approach. In terms of general strategy, the present study is considered a case study, and in terms of data analysis method, it is a mixed exploratory study. Data collection tools are provided through interviews, for data analysis in this research, software for converting recorded interviews to text and qualitative analysis using Maxqda software was used. The purpose of this research is to compile the governance model of the oceans and seas for the government of the Islamic Republic of Iran, and the grounded theory research approach based on the parametric approach is used. The statistical population of the research was maritime experts in the governance area of the Islamic Republic of Iran. The results are as follows that the requirement of a desirable unified governance is a correct understanding of causal preconditions such as political, financial and individual preconditions. The manner and extent of its impact on the category of international and national phenomena, its final attention to strategy. The basic principles of good governance, including attention to international relations, the development of the necessary cultural infrastructures, which have intervening conditions (developmental and organizational) and background factors (organizational, financial, political, and individual) May it ultimately have social, economic and political consequences for the government of the Islamic Republic of Iran.

The study area is located in the southeastern coast of the Iran, in Sistan and Baluchistan province. The sandy and shallow coasts of this region have provided a very suitable environment for the joining of bivalves, foraminifera and ostracods shells with a low degree of cementation and the formation of Lomashell (Coquinoid limestone) deposits. A large part of these deposits are used as borrow pits in the construction of breakwaters on the Makran coast. However; the evidence shows that these deposits have a high economic potential.

Therefore, in the present research, by identifying and introducing the Lomashell deposits of Makran coast, sampling them and investigating the geochemical characteristics of these deposits, the economic value of these ore has been evaluated and the possibility of using them to supplementing aquatic feed has been analyzed.

Based on the results of chemical analysis, the average amount of CaO in Lomashell is 44.76 %wt., equivalent to 86.91%wt of CaCO3. In addition, other nutrient elements and compounds such as Na, K, Fe, Mg and P are 1.03, 0.59, 1.36, 0.86 and 0.26 respectively. On the other hand, the average concentration of some toxic elements such as Pb, Zn, As, F, and Hg in Lomashell samples is 14.96, 12.8, 7.06, 19.43, and 18.33 (ppm), respectively. Compared to the very high concentration of calcium as ore mineral, they are insignificant.

The high purity of calcium carbonate, the low contamination with toxic and waste elements, the small amount of silica, in addition to the appropriate tonnage, the low range of vertical and lateral changes of the ore body, the low amount of gangue with ore deposits and also the bright color of the ore mineral, all of them represent the best quality of the ore mineral in three areas of Makran coast, and show that the Lomashell deposits has the best quality for processing micronized calcium carbonate powder in the preparation of food supplements for aquatic feed.

The purpose of this study to develop a framework for investigating the catch trend and estimation of optimized catch limit of the T. tonggol stock by collecting catch data in the Iranian southern waters.  In this research, the information of twenty-five years of catch of this species was prepared and with use of data limited approach and R software, estimation of optimal catch was made. The average catch (Ct) for this study period was 44609 tons (95% confidence interval 38882-53936 tons) and the average catch (R = 0.74, P < 0.05) increased significantly during the study period. Average (maximum-minimum) of carrying capacity (K), current biomass (B), maximum sustainable yield (MSY), biomass of maximum sustainable yield (BMSY) based on Catch-MSY (CMSY) model, Optimized catch-only model (OCOM) model and Zhou-Boosted regression tree models(Zhou-BRT) model was estimated and the mean reference points not show significant difference by statistical tests (P>0.05). This research shows that the annual harvest of Longtail tuna species has reached its maximum amount and no increase in fishing is suggested for this species.

Since 2011, the United Nations has held meetings to negotiate the possibility of creating a new international treaty to protect marine biodiversity. UN working group called the High Seas Alliance, with the participation of 27 non-governmental organizations, plus the International :union: for Conservation of Nature, is creating a new treaty to provide additional protection measures and improve the sustainable use of marine resources. The creation of an updated and binding legal framework to protect marine life in areas beyond national boundaries, known as the high seas, has been discussed for more than a decade, but previous efforts to reach an agreement have repeatedly stalled when Finally, for the first time, United Nations members agreed on Saturday, March 4, 2023, on a unified treaty to protect biodiversity in the high seas - nearly half of the planet's surface.

In this research, the international responsibility of governments and non-governmental organizations protection and sustainable exploitation of the environment and biodiversity in the sea beyond the exclusive economic zone was investigated using the descriptive-analytical method.

High seas and the seabed surface make up 45% of the earth's surface and make it a valuable resource. However, this valuable resource and all its organisms are now severely threatened by habitat loss, climate change, ocean acidification, pollution, and overexploitation in commercial fisheries.

As of 2023, there is no binding legal mechanism to establish marine protected areas outside the jurisdiction and sovereignty of countries, or to conduct environmental impact assessments. However, increasing impacts from overfishing, climate change, deep-sea mining, and shipping continue to impact biodiversity on the high seas negatively. Establishing a legal order from a different normative and structural perspective the High Sea, the ocean area that lies beyond the waters under the national jurisdiction of countries is the largest habitat on Earth and home to millions of species.

For the earthquakes and resulting tsunamis assessment in the Makran subduction zone, various earthquake scenarios defined, and the tsunamis waves associated with them modeled numerically. Based on the latest research results using thermal modeling, the maximum earthquake magnitudes considered in scenarios are 8.7 and 9.1. In contrast to previous studies that simulated Makran tsunamis using only a large-scale model containing topographic and hydrographic data with low resolution, the current research introduced a local model with finer spatial networks alongside the global model to calculate run-up accurately. Tsunami modeling was carried out considering different scenarios, using Boussinesq and non-linear shallow water models. The results indicate a significant importance difference in using Boussinesq and non-linear shallow water models. For smaller earthquakes like 8.3, the difference is much greater than for larger earthquakes like 9.1. This difference in the 8.3 earthquake may be due to the penetration of tsunami waves into the Chabahar bay and wave breaking inside the bay, where the Boussinesq model is more capable of accurately simulating wave breaking compared to the non-linear shallow water model. Meanwhile, for the 9.1 earthquake, due to the very high waves, most waves break before entering the bay and we observe less wave breaking inside the bay compared to the 8.3 earthquake scenario.