Entrainment of heavy metals into food chain is of main environmental problems. A big part of crude oil is exported to Western Europe and Japan through Strait of Hurmoz, thus this strait plays a strategic role in the world economy. This research dealt with some sedimentological characteristics and pollution degree of superficial sediment by As and Hg in Sirik and Jask ports, east of Strait of Hurmoz. Sediment samples were taken from 16 stations in Sirik and Jask harbors from depths of 5 and 10 m in January 2009. Sedimentological studies showed that the sediments in terms of size are very fine and close to clay particles. Average content of organic matter and calcium carbonate were 8.25 and 13.17 percent respectively. The pH varied from 8.6 to 9.2. The ICP-MS analysis showed that the average concentrations of As and Hg in Sirik were 5.28 and 0.027 ppm and were 4.52 and 0.038 in Jask respectively. Average values of enrichment factor for As and Hg were calculated as 16.77 and 1.93 in Sirik and, 11.36 and 2.14 in Jask respectively. These values indicate high and low enrichment for the measured elements as well as their non-crustal sources (agricultural and industrial wastewater and oil pollutions) in the sediments of the region. Neighboring agricultural land around Sirik and the oil spill event on 23 May, 2006 in Jask Harbor area justify the higher average pollution factor of As in Sirik (0.4) than in Jask (0.34). Comparison of Hg pollution degrees in Sirik and Jask stations (0.46 and 0.43 respectively) shows more contamination of sediments by As and Hg in Sirik stations.

This study aimed to measure the concentrations of lead and cadmium in the muscle tissue of Solen dactylus oyster in Tiab and Sirik areas located in Hormozgan province. To conduct this research, in the summer of 2018, 30 Solen dactylus oysters were collected from each of the mentioned areas and then bioassay operations were performed in the laboratory. Atomic absorption spectrophotometry was used to measure the concentration of lead and cadmium. Atomic absorption spectrophotometry was used to measure the concentration of lead and cadmium. The recorded results for the mean concentrations of lead and cadmium showed that there is a significant difference between Tiab and Siric stations (p≤0.05), And the highest mean concentrations of lead and cadmium were observed in oyster muscle tissue of knife handle, lead (0.761±0.065) and cadmium (0.506 ± 0.75) in the samples of Tiab station, respectively. The results show that factors such as the habitat of Solen dactylus affect the accumulation of heavy metals lead and cadmium, so that Tiab station shows higher pollution than Sirik station. On the other hand, the amount of these heavy metals in the oyster tissue of the knife handle at Tiab station is higher than the standard of the World Health Organization (WHO) and also in the Sirik region, the concentration of lead is lower and the concentration of cadmium is higher than the WHO. It turns out that the consumption of knife oysters both as shrimp food and by humans should be accompanied by health considerations.

The main fishing ground for shrimps in Hormozgan province along the Persian Gulf are located in the north of Qeshm Island to Sirik area with a yearly catch of 1500-2000 tons from east coast of Hormozgan province located in Iranian waters of Oman Sea.
Collection of breeder shrimps in important fishing grounds of Sirik to Jask area was started in 1995 for shrimp culture objectives and the present research was carried out in 2001 to 2002 and 2007, aiming at identifying shrimp species, determining frequency distribution of the species in the catch and evaluating shrimp maturity stages in the catch. Samples were collected using swept area methgd on a biweekly or monthly basis. Result showed that Fenneropenaeus indicus was dominant in the shrimp catch comprising 44.8-59.5% while this rate was 13.5-34% for Fenneropenaeus merguiensis, 15.7-20.5% for Penaeus semisulcatus, 5.5-16% for Metapenaeus affinis, 0-14.5% for M.stebbingi 0-4.5% for Parapenaeopsis stylifera in the Jask and Sirik areas in 2001-2002 and 2007. CLM50%was 34.7mm for F. indicus females, 31mm for F. merguiensis, 34.3mm for P. misulcatus and 27.16mm for M affinnis in Jask and Sirik areas. Tukey test showed that the average carapace length in F. indicus, F. merguiensis and P. semisulcatus caught in Jask were significantly larger than those from Sirik area (P<0.05). Sex ratio was not 1:1 in these shrimp species and there is significant differences between them (P<0.05). Maximum abundance of F. indicus, F. semisulcatus, M.affninis and F. merguiensis spawners, were found during March to June in Jask and June to July in Sirik areas.

Different coastal ecosystems, especially mangroves, are exposed permanently and almost simultaneously to multiple environmental stresses and disturbances (geological, physical, chemical and biological) which are varied in terms of their characteristics over time and space. The direct result of these stresses and disturbances is the reduction in area and health of mangroves and the subsequent exacerbation of global warming and other consequences of climate change, reduced coastal water quality, loss of biodiversity and degradation of coastal habitats. Considering the adverse consequences arising from the reduction in mangrove forest area, prioritizing management actions and providing appropriate infrastructure is essential to prevent a decrease in the extent of these ecosystems. Achieving this goal depends on having accurate and sufficient information and knowledge about the process of changes in the extent of mangrove forest habitats over time which can play an important role in the efficiency and success of rehabilitation programmes and the development of these ecosystems. Hence, the aim of this study was to investigate the long-term changes occurred in areas of mangrove forest of Hormozgan Province.
In this study, Landsat images from 1986, 2000, and 2016 were used to study changes in the extent of mangroves over time. The necessary pre-processing was doneconducted on images using Idrisi software. After extraction of the mangrove vegetation maps in the aforementioned years, changes in mangroves of the Khamir, Qeshm, Tiab, Sirik and Jask habitats were analyzed in ArcGIS software and the average values of areas of mangroves were calculated for two periods, namely pre- and post- 2000, and during a 30-year period.
The accuracy assessment of the classified images showed that the overall accuracy was equal to 92%. The results also showed that among the zones investigated (Khamir, Ghesh, Tiab, Sirik and Jask), Khamir habitat zone had the highest average annual value of area reduction (equal to -4.64 h/yr) and Sirik habitat zone had the highest average annual value of area expansion (equal to 23.5 h/yr) during the 30-year period. The results also showed that during period of 2000-2016, Sirik and Qeshm zones had the highest average value of expansion and reduction in area, respectively (equal to 32.47 and -21.38 h/yr, respectively). Analysis of mangrove area changes in different habitats showed that, despite the reduction in the extent of all mangroves in the period after 2000, the mangroves of Sirik habitat had significant increase in area in this period compared to the period before 2000 which was due to forestation with Avicenna and Rhizophora in the mud flats of this habitat in recent years.
The results of the study of changes in the areas of mangroves of Hormozgan Province showed that the trend of change the in area covered by the mangroves of Hormozgan Province over a 30-year period has been increasing from the coasts of the Persian Gulf to the Oman Sea; this indicates the impact of various environmental factors affecting the changes in the extent of the mangroves of the province. Finally it can be said that the results of this study, by providing up-to-date and accurate information about areas changes of mangrove habitat in Hormozgan Province, can help significantly to the planning of effective actions to protection and restoration of these habitats.

This investigation, which involved the satellite images together with simulation model, focuses on the effect of the sea hydrodynamics on coastal area classification. The study area is the North-West coasts of Oman Gulf. Mike 21 was employed to simulate the hydrodynamics of the Oman Gulf and Aster images were used to classify the coastal area applying Shepard’s method. Coastal classification of the area proposed the secondary coasts cover just 7% of the area including the Sirik headland and Jask regions. Intrusion of land toward the sea for Sirik headland and existence of longshore current in the area are the main reasons. The Jask area is located in transition zone between deep water of Oman Gulf and shallow water of Hormoz Strait, was influenced by marine affects.

Coccolithophores are one of the main groups of marine phytoplankton playing key roles in the marine ecosystem as primary producers and in marine biogeochemistry. These organisms have gained considerable attention as they play a unique role in the global carbon cycle because of their combined effects on both the organic carbon and the carbonate pump. Although steady advances in research on coccoliths as biogeochemical agents and palaeontological proxies were obtained knowledge of the biology of these organisms has only progressed considerably in recent years. Calcareous nannoplanktons are one of the most important of phytoplankton for reconstruction of paleoinvironmentThe Persian Gulf Basin, is found between the Eurasian and the Arabian Plates. The Persian Gulf is described as a shallow marginal sea of the Indian Ocean that is located between the south western side of Iran and the Arabian Peninsula and south and southeastern side of Oman and the United Arab Emirates. Other countries that border the Persian Gulf basin include; Saudi Arabia, Qatar, Kuwait, Bahrain and Iraq. The Gulf extends a distance of 1000 km with an area of 240,000 square km. The Persian Gulf basin is a wedge-shaped foreland basin which lies beneath the western Zagros thrust and was created as a result of the collision between the Arabian and Eurasian plates. The Strait of Hormuz is the only link between the Gulf and the open water of Arabian Sea and Indian Ocean. It lies between Iran and a tiny separated territory of the Sultanate of Oman on the Arabian Peninsula. Measured along the median line, the Strait is about one hundred and four miles long but narrows to only twenty nautical miles at the northeastern end between Larak Island on the Iranian side, and the Quioins on the Omani side. The ability to reconstruct historical sea-surface salinity (SSS) patterns is essential to understanding past ocean circulation and climatic change. The calcareous nannoplankton is, as the most groups of marine organism, very sensitive to salinity fluctuations. The family Braarudosphaeraceae is one of the oldest extant coccolithophore families, it is distinguished by having a coccosphere formed of five-fold symmetric calcareous scales called pentaliths. The family has a long fossil record extending back to the Early Cretaceous. In the geological record, they show greater morphological variation in their pentaliths than in modern populations. Based on the morphology of the five segments forming a pentalith, six genera have been recognized in the Braarudosphaeraceae. Besides, although typical marine taxa, a few coccolithophores live in brackish waters and even in fresh ones. In the literature, Braarudosphaera bigelowii is often described as a species living in low-salinity coastal waters, since it is rarely recorded from the open oceanThe species Braarudosphaera bigelowii, a taxon confined mostly to shallow marine environment (first appearing in the Lower Cretaceous), is a good indicator of salinity fluctuations. Braarudosphaera bigelowii lives in the coastal areas, low salinity water and with entrancing of clastic materials. Low-salinity waters and unusual current conditions have also been put forward as a possible cause for past Braarudosphaerid blooms. The studies done on samples of the Persian Gulf, East of Strait of Hormuz and Oman Sea based on distribution of this species showed that in the study area frequency of this species very low and presence of this species in the western part of the Persian Gulf related to the entrance of fresh water to this area. the inflow of Arabian Sea waters occurs mainly in the northern part of the strait and forms a low-salinity wedge intruding westward into the gulf along the southern coast of Iran. Cyclonic circulation within the gulf carries these waters to the northwestern and shallow southeastern areas of the gulf where they are transformed to dense, saline waters which sink into the axial trough of the Persian Gulf and exit through the deepest part of the strait off northern Oman. A recent compilation of hydrographic data from the gulf indicates that the densest waters are formed in the northern gulf during winter, and that these waters propagate southward toward the Straits of Hormuz throughout the year. Slightly less dense, though saltier, waters are formed on the shallow southeastern shelves, which spill more intermittently into the deep gulf. While the general features of the exchange flow through the Straits of Hormuz are understood, the magnitude of the exchange is still poorly known because of large uncertainties in estimates of evaporation over the Persian Gulf. Evaporation and salinity in central part of the Persian Gulf are high and frequency of B.bigelowii is very low and finally in the East Stratit of Hormuz and Oman Sea the amount of salinity is high and in these parts B.bigelowii are rare.

The main purpose of this study is to investigate the effect of complex elaboration strategies on mathematical anxiety and academic achievement of primary school male students in Sirik city in 2009-2010. The research method was applied and quasi-experimental. The statistical population of the study includes all male elementary school students in Sirik city. The method was multi-stage random cluster sampling in which 60 people were divided into experimental and control groups (30 people in each group). Mathematical anxiety questionnaire and math lesson scores were collected for both groups, and then only 8 sessions of complex strategy development classes were conducted for the experimental group, and no training was provided for the control group, then again the post-test questionnaires for both The group performed. Data were collected and analyzed using analysis of covariance in SPSS19 statistical software. Findings showed that there is a significant difference between the control and experimental groups in math anxiety and students 'academic achievement. As a result, complex description strategies are effective in math anxiety and students' academic achievement.

Advances in remote sensing enable fast mangrove mapping the less need for intensive fieldwork, complex and heavy processing, and skill-based classification techniques. In this research, mangrove forest mapping was performed using Sentinel-2 satellite images in Google Earth Engine (GEE) in Hormozgan province in three ecosystems of Qeshm, Khamir, and Sirik. For this purpose, all steps of mapping these forests, including pre-processing and classification were performed in the GEE. The Modular Mangrove Recognition Index (MMRI) and classic spectral indices were also used to highlight the spectral differentiation of mangrove cover from the surroundings. To classify the image of the study area, three land cover classes were used: mangrove, non-mangrove, and sea (water). The classification was performed based on the random forest algorithm and accuracy assessment was evaluated in R software based on the K-fold validation method. The Qeshm site was demonstrated the highest accuracy among the three ecosystems with an overall accuracy of 98% and a kappa of 0.73. Khamir and Sirik sites were shown an overall accuracy of 97% and a kappa value of 0.71 and 0.70, respectively. The MMRI index was the most important variable in the RF classification in Qeshm and Khamir, while in Sirik, the SAVI index was the most important spectral index in mangrove map providing. The overall accuracy of over 95% at all three sites indicates that combining Sentinel-2 data using appropriate indices in the GEE is an effective approach to mangrove forest mapping

Mangrove forests are known as important sea carbon ecosystems because they play an important role in carbon sequestration among coastal ecosystems. This coastal ecosystem has 10 to 50 times more carbon sequestration capacity compared to terrestrial ecosystems, and among the most productive systems, they can effectively reduce climate change. Therefore, an accurate estimation of the biomass of mangrove forests is a necessity. Meanwhile, the evaluation of the terrestrial carbon storage in mangrove forests relies on the accurate measurement of tree biomass, which is traditionally time-consuming and expensive. In this study, height and crown diameter was estimated by using UAV equipped with an RGB sensor; following sampling and measuring soil carbon in three forest sites of Sirik, Qeshm, and Khamir, the carbon storage in trees and soil was investigated. Orthophoto mosaic and dense point cloud were created based on structure from motion algorithm. Crown diameters were extracted from orthophotos. The canopy height model was extracted by subtracting the digital surface model and digital terrain model which were derived from point cloud. Tree heights were extracted from the canopy height model following imaging in November 2021. Considering that there was no significant difference between the measured variables on the ground and the extracted variables from the UAV images, the data obtained from the UAV images and allometric equations were used to estimate the aboveground carbon storage.  After estimating the biomass according to the two variables of crown diameter and tree height, the carbon storage on land obtained from the information extracted from UAV images in the three sites of Sirik, Khamir, and Qeshm was obtained at 11.63, 7.97, and 9.87 t/ha respectively. The soil carbon was also measured at two depths of 0 to 15 cm and 15 to 30 cm using the Walkley-Black method, and the values were shown as 67.98, 81.9, 85 t/ha, and 187.2, 133.53, and 113.7 for Sirik, Khamir, and Qeshm sites. This research shows that UAV data has a high ability to estimate the variables related to individual trees in forest areas with difficult traffic conditions, and subsequently to estimate the height and crown diameter variables, estimate the forest stock and carbon storage based on the mentioned variables. It can be achieved in relatively homogeneous mangrove forests. Especially because these ecosystems are environments that are often inaccessible or difficult to work in.