مجله علوم و فنون دریایی
سال بیست و دوم شماره 2 (تابستان 1402)

Port has always played a strategic role in domestic and foreign trade growth for developed and developing countries. As the world moves towards globalization and distances are steadily narrowing, ports have gained a more active role in the economic growth of the country and are no longer just a passive operator for transportation. Port networking is a relatively new idea that has been the focus of leading shipping countries in recent years. In the networking approach, small and large ports can interact with one another in a larger network as part of the whole, helping stakeholders and organizations fulfil their provisions. In this research, the focus is on commercial ports of Bushehr Province, including Bushehr, Deylam, Genaveh, Rig, Morvarid Kharg, Mohammed Ameri, Buolkheir, Ameri, Dayer, Kangan, Nakhl Taghi and Asalouyeh. At first, using Delphi method, port evaluation indicators were determined and accordingly, ports of Bushehr province were operationaly classified in three levels and geographically in three groups. Finally, by placing the mentioned ports in the transportation networking models, a dynamic networking model for the ports of Bushehr province is presented.

The aim of this article is to examine household’s behavior in the area of see food consumption. For this reason, data for 38900 Iranian urban and rural households in 2012-2013, which provided by Iran bureau of statistic (IBS) is used to estimate the demand and analyze consumer behavior for fish, shrimp and other sea food items in Iran. Data revealed that many households were not potentially see food consumer and reported zero consumption. Missed data and zero consumption is considered as a character of household level data. Hence, Tobit and Heckman two step procedure is used as two alternatives to deal with zero data as an appropriate estimation procedure. based on findings, Heckman two step procedure has more explanatory power than tobit. Also, Economic factor such as Family Income, Demographic ones, such as Household head education, household size and average age of family, and geographic factors will affect see food consumption.

The increasing application of remote sensing for mangrove mapping and monitoring is practical for sustainable management of the biological resources. The emergence of several vegetation indices (VIs) has certainly given significant impacts on mangrove and other forest mappings. In this study, four different vegetation indices including Normalized Different Vegetation Index (NDVI), Simple Ratio (SR), Soil Adjusted Vegetation Index (SAVI) and Triangular Vegetation Index (TVI) were compared to discover a suitable vegetation index for identifying mangrove area in Nayband bay, Boushehr, Iran and using landsat imagery with 30-m from 2012. Maximum Likelihood Classifier (MLC) was used to classify Mangrove and NonMangrove area. The results demonstrated that the best accuracy (96.85%) was from combination between 7 landsats spectral bands and some vegetation indices including NDVI and SAVI.

The present study was conducted to investigate length selectivity and determine optimal meshsize for fishery of Longtail Tuna (Thunnus tonggol) surface drift gillnets in northeast of Oman Sea and fishing grounds of Chabahar, Konarak and Ramin (Sistan and Baluchistan Province) from October 2016 to June 2017. Fishing gear was included Longtail Tuna surface drift gillnets with 100, 110, 130 and 165 mm stretched mesh size. During 45 stages of navigation with fiberglass boats and wooden vessel, 477 fish specimen were caught, which recorded length frequency data, total weight, and operculum and body girth. A total of 228 samples were Dissected and their ovarian maturation stages were determined to estimate the length of sexual maturity (Lm50). The minimum, maximum and mean (± standard deviation) fork length of the samples were 32, 90 and 55.1±13.35 cm, respectively. Operculum girth-fork length and maximum girth-length relationship were obtained as: Gop = 0.5379 FL+0.4955 and Gmax = 0.5879 FL+ 0.5095, respectively. Size at first maturity (Lm50) of Longtail Tuna was obtained 53.7 cm FL. Using Sechin selectivity method, optimal catch size of 100, 110, 130 and 165 mm gillnet mesh sizes were determined as: 35, 38, 46 and 57 cm, respectively. Using selection coefficient and Lm50, standard mesh size for fishing Longtail Tuna were determined 170 mm. Due to the fact that immature fish are not caught by a 165 mm mesh, this mesh may be suitable, and this confirms the calculation of the standard mesh size of this net by the Sachin method.

The aim of this study was to investigate the effect of selenium, magnesium nanoparticles and their composition on growth and digestive enzymes of Asian seabass with a mean weight of 32.78±1.16 g for 42 days. After adaptation to the experimental conditions, 96 fish were randomly distributed in 12 fiberglass cylinder 300-liter tanks in equal numbers. Four treatments including control treatment, 4mg / kg nanoselenium, 500mg / kg nanomagnasium and combination of 4mg/ kg nanoselenium with 500mg / kg nanomagnasium were investigated. The fish were fed daily in satiation and up to 3% of body weight in two time a day. Samples needed to measure growth indices and digestive enzymes were collected at the end of the period. The results showed that in the fish fed the combined treatment, the highest body weight gain was 131.33±26.58 and the specific growth rate was 2.08±0.28 and there was a significant difference between the control treatment (65.01±21.26 and 1.23±0.32, respectively) (P <0.05). The results of this study showed that digestive enzymes of alkaline phosphatase, lipase, trypsin and chymotrypsin were significantly different between experimental treatments (P <0.05), so that the highest activity of alkaline phosphatase in nanoselenium treatment (611.06±82.00U/mg protein),  the highest amount of lipase (0.86±0.03 U/mg protein), trypsin (0.054 ± 0.001 U/mg protein), and chymotrypsin (0.214±0.004U/mg protein) was seen in nanomagnesium treatment (P <0.05), whereas the amylase enzyme showed no significant difference between the experimental treatments (P> 0.05). The results of this study showed that the addition of selenium and magnesium nanoparticles to the diet of Asian Sea bass had positive effects on growth performance and digestive enzymes and suggested that magnesium nanoparticle supplementation (500 mg/kg) could be used alone or in combination with selenium nanoparticles (4 mg/kg nano-selenium and 500 mg / kg nano-magnesium) in the diet of Asian Sea bass.

The seizure of ships in different maritime territories is one of the basic challenges of the international law of the seas, which leads to legal disputes between flag and coastal states and sometimes third states. On Tuesday, April 19, 2022, the Greek Coast Guard seized the Russian tanker Pegas/Lana, which was carrying an Iranian oil cargo, in the waters of the Greek island of Oia, due to the violation of US and European Union sanctions against Russia in connection with the attack on Ukraine, and the Iranian oil cargo at the request of American judicial authorities. This action was met with protest by the authorities of the Islamic Republic of Iran, and despite diplomatic efforts to resolve the disputes peacefully, two Greek oil tankers were seized by the Islamic Revolutionary Guard Corps with a court order and a complaint from the owner of the oil tanker Lana. Therefore, the purpose of this brief is to examine these seizures from the perspective of the international law of the seas, and to answer the question, whether the actions of Greece and Iran are legitimate or not from the perspective of the international law of the seas? The research method of this article is descriptive and analytical, and the method of collecting library information is documentary. The findings of the research indicate that the seizure of Iran's oil cargo by Greece and the United States is in contradiction with the peaceful use of the seas and freedom of navigation. Regarding Iran's actions, considering that according to the statements of the Greek Ministry of Foreign Affairs, the location of the seizure of these two oil tankers was in the monitoring zone and the territorial sea of Iran, the Islamic Republic of Iran has jurisdiction and according to the verdict issued by the judicial authorities due to maritime violations. He has seized Greek oil tankers.

In recent years, mangrove ecosystems have been threatened by effects of global climate change, in addition to human destructions. One of the most important impacts caused by climate change on mangroves, is the global sea- level rise and consequently, inundation of parts of coastal zone. Rising sea- level causes mangrove retreat in many areas. However, in some regions, human settlements and coastal structures and facilities, act as limiting factors. In this study, using the two scenarios of the lowest and highest mean sea level rise over the period of 2046-2065, according to IPCC report and the results of internal studies, inundation zones caused by sea level rise in the two protected areas of Harra in Bandar Khamir and Harra Tiab and Minab was determined. Results demonstrated that if the sea level rises, the lowest and highest levels of inundation, will be 1000 and 2000 hectares respectively in Harra protected area, and about 3500 and 7000 hectares, respectively in the protected area of Tiab and Minab. Results of land cover and land use showed that, most of the hinterland, is related to poor rangeland cover and empty lands and according to regional and global predictions in sea- level rise, there is currently no barrier for mangrove migration into hinterland, but in next few years and in the future plans, land use changes need to be addressed to make more appropriate management decisions to protect these valuable ecosystems.