فصلنامه اقیانوس شناسی
پیاپی 43 (پاییز 1399)

In this research, paleoecology of Baghmashah Formation in Rizu section based on calcareous nannoplanktons has been investigated. Baghmashah Formation is part of the Mago sedimentary mega sequence in the Tabas block that was located in the northern margin of the Neotethys Ocean in Jurassic-Cretaceous. The Baghmshah Formation in this section with 270m thickness mainly includes the alternation of green marl- shale with thin interlayers of calcareous sandstone. The study of calcareous nannofossils and index species of nannofossil indicates Berriasian- early Huterivian age for the Baghmashah Formation in this section. Investigation of the abundance of calcareous nannofossils in the studied section shows that the sedimentary basin of Baghmashah Formation in Rizu section located in low latitude with warm surface waters, and formation deposited in oligotrophic conditions with shallow environment.

Given the importance of sea turtle nesting beaches on the coast of Sistan and Baluchistan province, this project with the purpose of research and conservation of spawning habitat was conducted in 2018. The coast by the executive team and locals were monitored.Examining the Sistan and Baluchistan province, about 300 km off the coast of northern makoran Sea indicates the existence of 13 important site sea turtle nesting area. A species that lay the egg during this project was green sea turtle (Chelonia mydas). The results of this study shows that the nest site selection success were 44.3%,63%,81.4% and 52.6% observed in Tang, Ramin, Lipar and Kacho, respectively. The results represent that highest nest site selection success was in Ramin. Results from the coast of the province of Sistan and Balochistan shows different morphology. The results of this study indicate that the maximum number of green turtle eggs (C.mydas) were observed in Ramin. The results show that the green sea turtle (C.mydas) habitats on the coast of Sistan and Baluchestan province are diverse and can be classified as sensitive areas of the coast, which is necessary for the implementation of conservation plans.

One of the recently considered pollutants is microplastic particles. To investigate this contaminant, 15 samples of sediment were sampled from Khor-e-Musa estuary. Samples were transferred to the laboratory in thick plastic bags for extraction and counting of microplastic particles. H2O2 was first used to remove organic matter in the samples. Then, using the condensation separation method, the microplastic particles were separated from the sediment particles and finally identified and counted by using binocular optical microscopy. The average concentration of microplastic particles in the study area was 11.67 per 250 g of sediment and the maximum and minimum concentrations were 22 and 1, respectively. In this study, about 49% of the found microplastics were stringed, 36% multifaceted, and 14% spherical. The predominant color of these particles was white/transparent and black/gray, which accounted for 32% and 36% of the total microplastics, respectively. Also, about 13, 14, and 5 percent of the microplastics were yellow/orange, red/pink, and blue/green, respectively. In general, about 52, 33, 8, 3, and 3% of microplastics are related to microplastic particles with sizes less than 100, from 100 to 250, from 250 to 500, from 500 to 1000, and from 1000 to 1000, respectively. It was 5,000 micrometers. The results of this study showed that microplastic particles are present in the sediments of Khor Musa and most of these particles are filamentous and with dimensions of less than 100 micrometers. This means that the adsorption capacity of these particles is high for pollutants.

The discovery of marine genetic resources has led to increase of the number of international maritime patent claims .Given the unique characteristics of these organisms, the genetic resources derived from these organisms have great potential in the medical field and for research and development in the fields of antioxidants, fungal treatments, AIDS, cancer, tuberculosis, malaria And antibiotics are of particular value. Given that most marine genetic resources exist in areas beyond the national jurisdiction, so far, international law, including the Convention on Biological Diversity and the Convention on International Maritime Law, does not have the necessary and complete mechanism to regulate access and management of these resources. For this reason, the General Assembly, by issuing Resolution 292/69 in 2015, acknowledged the need for a new international agreement in accordance with the Convention on the law of the Sea in the field of conservation and sustainable use of biodiversity. In this paper, while examining the position of marine genetic resources in the international law system, we pay attention to the traditional knowledge and rights of indigenous peoples while exploiting genetic resources and the patent system and consider new international law innovations to resolve existing conflicts.

Assuming the possible scenario ICCP RCP8.5, by 2100, the pH of seawater in Hengam coral reef in the Persian Gulf will decrease by 0.46 compared to 1880 (to less than 7.72). Total dissolved inorganic carbon will increase from 2006 to 2263 µmol/kg. The concentration of bicarbonate ions will increase by 24% and the carbonate ions will decrease by 51%. The saturation of calcium carbonate in seawater will be reduced by more than 50 percent, possibly leading to a 38 percent decrease in the calcification rate of Hengam Island corals compared to pre-industrial. Given that the rate of erosion and calcification in the corals of the Persian Gulf is somewhat close, at the end of the century, with the decrease in the rate of calcification and increasing the rate of erosion of corals, an unfortunate outcome awaits the corals of the Persian Gulf.

Color and sensory characteristics have a key effect on consumerchr('39')s preferences of fish product. Hence, the aim of present study was to explore the effects of two stunning/slaughtering methods including electroshock and asphyxia in the air on color and sensory characteristics of cultured silver carp. The results showed all color indices changed significantly across both treatments at the end of study (p<0.05). However, comparing the results indicated only redness (a*) and yellowness (b*) indices showed significant differences between both methods. a* and b* indices were significantly higher in electroshock and asphyxia methods, respectively. Also, the results showed significant increase (P<0.05) in the quality index of fish during the storage time and their scores reached to 10 and 9.3, respectively. However, the results of quality indices indicated lower speed rate of changes in sensory characteristics in electroshock methods during storage time.

Atmospheric ocean linkage signals are one of the most important drivers of climate anomalies. These cycles around climate linkage can play a key role in the whitening and death of coral colonies by altering the temperature characteristics of the water surface of each region. The main purpose of this study is to evaluate the effect of large-scale oceanic signal signals on the bleaching episodes of Persian Gulf coral reefs. In this regard, data related to 35 indicators of climate linkage cycle during the statistical period 1980-2015 (36-year period) were obtained from the Climate Prediction Center of the United States Oceanic Atmosphere Base (NOAA). The whitening episodes of the Gulf of Persia were also extracted from the Global Coral Monitoring Base. The results of correlation analysis showed that among the 35 major oceanic atmospheric linkage indices influencing the Earthchr('39')s climate, two Atlantic multi-decade oscillation (AMO) and the equatorial Pacific water temperature change index in the NINO3.4 region, With sea surface temperature anomalies in the Persian Gulf region, it has provided a significant correlation at the level of confidence of 0.95. The apparent correlation of water surface temperature in the Gulf of Persia region during the warm season months (June to September), when there was the highest risk of water whitening, indicated that two indicators, AMO and NINO3.4, were able to justify the significance of bleaching episodes. The results of the analysis of the frequency of bleaching events in the Persian Gulf corals indicated that all recorded events were related to the positive phase of AMO. In the case of the NINO3.4 index, a similar result was obtained that the positive phase of this bonding pattern caused high risk temperatures in the Persian Gulf and caused general bleaching events in the coral reefs of this region, so that out of 12 occurrences in the region, 7 cases This index has been recorded in the positive phase and only 3 cases have been in the negative phase. Knowing that these two linkage patterns are among the 35 main climate control linkage patterns, they are the main drivers of coral bleaching and mortality in the Persian Gulf, so with careful knowledge and monitoring of these linkage patterns, protection measures can be taken to a large extent. For coral colonies in the region performed more efficiently.

This paper investigates and estimates the surface salinity changes of the Persian Gulf using the FVCOM numerical model. Sea level salinity (SSS) is one of the important parameters in oceanographic studies. The Persian Gulf is a semi-closed and shallow sea, which is high in the Persian Gulf due to its low rainfall, salinity and water density. One of the limitations of this region is the lack of field data related to the surface salinity of seawater. The main purpose of this study is to investigate the surface salinity of water using the FVCOM numerical model, which has been studied at a depth of 1 meter from the surface. In this model, wind, tidal, heat flux, temperature and salinity data have been applied in the model. First, for 5 years (2005-2009), the model was implemented and the results obtained by the model were compared with field observations in the Persian Gulf, which have a very good agreement.

This paper investigates and estimates the surface salinity changes of the Persian Gulf using the FVCOM numerical model. Sea level salinity (SSS) is one of the important parameters in oceanographic studies. The Persian Gulf is a semi-closed and shallow sea, which is high in the Persian Gulf due to its low rainfall, salinity and water density. One of the limitations of this region is the lack of field data related to the surface salinity of seawater. The main purpose of this study is to investigate the surface salinity of water using the FVCOM numerical model, which has been studied at a depth of 1 meter from the surface. In this model, wind, tidal, heat flux, temperature and salinity data have been applied in the model. First, for 5 years (2005-2009), the model was implemented and the results obtained by the model were compared with field observations in the Persian Gulf, which have a very good agreement.