Estuaries play an important role in environmental protection, biodiversity, flood control and drinking water supply and can play an important role in the production of biological materials and the production of medicinal plants. Hormozgan province as a coastal province in the south of Iran has several wetlands. For this purpose, to identify and determine the abundance of Benthose of the international wetlands of the estuary of Shoor, Shirin and Minab in Tiab estuary and Yek shabe in 2016 seasonally. For this purpose, sampling of sediments was carried out using a Van veen grab with a cross section of 0.04 m2 in two estuaries. In this study, different groups of Macrobenthos (Annelida, Mollusca, Crustacea and other macrobenthos (Nemertea, Fish larvae and Echinodermata)) were identified. 23 families of Polychaetes, 5 families of Bivalves, 6 families of Gastropods, 7 families of Arthropods, 2 families of Foraminifera and 1 family of Sipuncula were also identified as 37 genera and 9 species of different families suitable for Tiab. Most abundance belonged to the Foraminifera and also the polychaetes had a considerable abundance. The results of this study showed that a total of polychaetes (17 families), bivalves (5 families), Gastropods (11 families), Scaphopoda (1 family), Arthropods (3 families) and 1 family of Foraminifera as well as 37 genera and 9 species were identified in Yek shabe estuary. Macrobenthos in Tiab estuary with an average of 9428±4376 n/m2 had a higher abundance and Yek shabe estuary with an average of 2.78±0.55 g/m2 had a higher weight macrobenthos in Tiab estuary with average of 9428±4376 n/m2 had higher abundance and in Yek shabe estuary with average of 2.78±0.55 g/m2 had higher weight. According to the results of this study, in general, the abundance of macrobenthos in the Yek shabe estuary was lower than the Tiab estuary, while the weight of all organisms in the Yek shabe estuary was higher than the Tiab estuary. Although several factors affect the final weight of macrobenthos in an area, it seems that the conditions are suitable Yek shabe to provide a greater opportunity for the presence of macrobenthos, followed by feeding, growth and increase in body size and ultimately weight gain.

The purpose of this study was investigate the overwintering Scolopacidae population in the two regions Hara Protected Area (HPA) and Haray Tiab and Minab (Kolahy, Hasan langhi and tiab Estuaries) in the Hormozgan Provence between 2007 and 2012, respectively. According to the results of a 6-year period, A total of 22 species from Scolopacidae have overwintering in the study Areas Which the number of species observed in the HPA and Kolahy, Hasan langhi, and tiab Estuaries was 20,20,17,19 species. Among the species identified from the Scolopacidae In the period that was studied, Two species Dunlin(Calidris alpina) and Eurasian Curlew(Numenius arquata) Respectively 41/08 and 17/26 percent of total observations, were The most abundant species. According to the findings of this study the most observed population was related to HPA(37054 Bird) And the lowest was in the kolahy eustary (5949Bird). Evaluation of biodiversity index and diversity graph sorting by Renyi method showed Hassan langhi estuary with species diversity indices Shannon-Wiener’s(2/18) and Simpson’d(7/14), And The values for Species Abundance(17) and indexes of the evenness Pielou J (0/69)and McIntosh E(0/82)compared to Other areas the has higher biodiversity (P<0/05) And been able to provide the suitable habitat for Scolopacidae. On the other, Analysis of Similarity Percentages(SIMPER) for Hara protected area and Kolahy, Hasan langhi and tiab Estuaries in Ordering was %61/11, %55/89, %46/20 and%63/75. Analysis of Similarity(ANOSIM) Indicated that between HPA and and Kolahy, Hasan langhi and tiab Estuaries And Also Between Hasan langhi estuary And Kolahi estuary There is significant difference between the relative similarity of the total observations (P<0/05). Distribution of the of species in the HPA and tow estuary of Kolahi and tiab from Logarithmic series distribution model and in Hasan langhi estuary from Broken stick model were subordination.

Density and seasonal changes of polychaet communities in Tiab estuary, located in Hormozgan province, were studied at different seasons in 2015. Sampling from 4 stations was performed using Van vin Garb (0.04 m2) in triplicates. The average total density of Polychaetes (±sd) was 226.04±193.06 per square meter. 21 families, 28 genera and 39 species were identified. The Cossuridae family had the highest frequency (38.8%). The highest average of Margalef index recorded in station 1 (4.6) and those lowest in station 2 (2.8). Regarding Shannon index, the maximum and minimum value were recorded in station 3 (2.7) and station 1 (2.2), respectively. The results of multivariate CAP analysis showed the effective relationship between environmental parameters and dominant Polychaetes. It was found that Aglaophamus malmgreni was the indicator species of station 4 in all seasons and the most important parameters affecting the distribution of this species were TOM, Silt and NO3. It was also shown that Cossura longocirrata is the dominant species of station 2 in spring and the amount of oxygen and increasing its concentration showed a close relationship with the distribution pattern of this species in the presence of the predominant presence of Prionospio steenstrupi at the same station in summer. Chlorophyll a was as an effective factor in distribution of this species. In the case of Cossura spp. and Nephtys spp. It was found that higher temperature with high concentration of PO4 and at the same time the species are resistant to oxygen deficiency and finally PO4 was identified as the most important factor affecting the distribution of Prionospio banyulensis as the dominant species in stations 1 and 3. The results showed Tiab Estuary with high biodiversity, balanced distribution of Polychaets and dominant sensitive species to pollution and environmental stress and the fluctuation of Polychaete communities is influenced by seasonal fluctuations and quality of water and sediment parameters in this aquatic ecosystem.

The purpose of this study was to evaluate the effects of environmental parameters on the dinoflagellates cyst abundance of Gonyaulacales and Gymnodiales orders in the sediment of Oman Sea coastal regions and the Strait of Hormuz in winter and spring 2015. Dinoflagellate cyst study helps to identify key areas for the feature bloom of harmful species. For this purpose, sediment sampling was carried out by Grab (Ekman) at 15 stations located in the Pasabandar, Ramin, Konarak, Galak and the first Tiab estuary in the Strait of Hormuz. Salinity, temperature, acidity and depth of water column were measured in each station. The sediment grain size and the total organic matter content of the sediment were measured in the laboratory and dinoflagellate cysts were isolated, identified and counted. The relationship between the environmental parameters and the species of dinoflagellate cysts was studied by the ordination method of canonical correspondence analysis(CCA). The ordination results of CCA showed that the abundance of dinoflagellate cysts was significantly affected by the environmental parameters and the sediment grain size (P

Numerical index of diversity, Combination of species richness and evenness are two important components But one of the Important problems of This indexes is this Do not separate the contributions of these two components is the numeric index value. One of the most effective and efficient methods to compute Contribution of these two components is the numeral diversity of SHE analysis The method of calculating the two components permits. This review is from mid- winter census water birds of Hasan langhi(Namaki), kolahi and tiab estuaries During the six years(1385-1390) In order to clarify Factors influencing the Numerical index of diversity was used. Calculation of diversity indices showed The variation in tiab, Hasan langhi and kolahi estuaries In order to 1388,1388,1389 Higher than other years, Shannon Wiener diversity index, Pielou J Richness index was the same frequency as and Evenness index, where (H'=3/15),(44) and (j'=0/75);( H'=3/2),(41) and (j'=0/79);( H'=2/99),(37)and(j'=0/74) Respectively. The results indicate that the factors influencing the numerical index variation is uniform in all three components of the estuary. In this period of intense change the landscape for birds Been observed in three assorted which means that the species composition have been relatively consistent.

Estuaries are transition zones between the sea and land, and are constantly affected by tides. These areas are biologically important and sensitive. Tiab estuary, 7 km from away from the coast of Strait of Hormuz, is covered with mangroves and is also used for navigation by small commercial boats. This estuary is facing sedimentation issues nowadays which troubled navigation of vessels. Since the local wind conditions of the area is different seasonally, the influence of this difference on the transformation of the shoreline is considered for the years 2019 and 2020. The wind direction in the area is mainly SSW during summer, while is totally diverse during winter. Sentinel-2 satellite images have been used with similar water-level conditions. Normalized Difference Water Index and K-means algorithm are used for shoreline detection. The results show that the area of the estuary is more than 10 hectares smaller in summertime than in wintertime. The correlation coefficient of the seasonal transformation of the shoreline in 2019 and 2020 is 0.84, which shows that the seasonal transformation was similar in the two years. Shoreline transformation was at most along the curvatures of the river, whether in upstream or downstream. It was however varied between 45 and 200m. Some dissimilarity in shoreline transformation was detected between the two years of study, specifically in upstream of the river, which is suggested to be due to human activities. It is believed that those parts of the estuary with high transformation are subject to permanent transformation in long term.

They can be therefore the mouth of a route through the open oceans. Tiab Estuary, located 30 kms away from the Minab city, is a channel overflowed to the Persian Gulf and the Strait of Hormuz. In this field investigation 5 stations along the channel have been selected for measurements. Two cruises were carried out in the 23rd of Mehr and 28th of Aban of 1394 (October 15 to November 19, 2015). In the former cruise the measurements were carried out along the channel for a period of about 12 hours. The latter cruise however, took place at the middle of the channel during one tidal cycle. The instruments used, were a CTD, a Niskin sampler bottle, and a grub. The results derived from this investigation show that the increase in the suspended sediment concentration happen during the ebb condition, specifically at the mouth of the estuary. It was also found that the grain size distribution of the bed load is decreasing from the mouth of the channel toward the basin. At the basin the silt and clay percentage is about 40.71%, while at the mouth of the channel this amount reduces to about 3.48%.

The estuaries are one of the most important coastal natural resources. Chlorophyll-a (Chl-a) monitoring, which is the pigment of oceanic and coastal phytoplankton, can be measured and evaluated using new remote sensing technology. The presence of blue, green and red wavelengths in oceanic observation satellites has always paved the way for monitoring the color of the oceans. The aim of this study is used OC2 and OC3 bio-optical algorithms and Sentinel-2 MSI and Landsat-8 OLI satellite data in April 2019 to estimate chlorophyll-a concentration in the estuary Tiap area. Ground sampling data were carried out to correlate and evaluate the results. The results showed that the OC2 algorithm in Landsat-8 and Sentinel-2 satellites had the highest R Squared coefficient (R2) 0.91 and 0.64, respectively, and the Root mean square error (RMSe) of the satellite images were 0.13 and 0.33, respectively. These results indicate the high accuracy of the OC2 algorithm in the satellite images used and were selected as the most suitable algorithm for mapping chlorophyll-a concentration in the study area.

Tiab and Kolahy estuaries are regarded as part of the Ramsar sites, that are located in the delta of Rud Shirin, Rud Shour and Minab River 37o 05' N 56o 50' E. The total area of the region is about 20000 ha. In this study, 96 species from 27 families of the birds of Iran were recognized at these wetlands.Fifty seven species were waterbirds. Species of White and Dalmation Pelicans,Great Cormorant, Greazer Flamingo and some Gulls and Terns were counted monthly in this survey. All species were migrant birds. Density of birds population in Kolahy was 2/99 and in Tiab 3,00 per hectare. There was no significant statistical difference between populations and species diversity of any known species in both estuaries. The bird's population in both wetlands were maximum in winter and minimum in summer, from which 60% were Fish-eating, 35% omnivores and the remaining were Planktoneater. Dalmation Pelican Pelecanus crispus, one of the threatened species observed in winter in both estuaries. Diversity of Sternidae with 9 species was more than the other bird family and Phoenicopterus ruber and Phalacrocorax carbo with one species werethe families with lowest bird species number.

In the current work, a comprehensive assessment of the spatial distribution of heavy metals including Cd, Pb, Ni, Cu, Zn, and Cr was performed in the sediments of mangrove and coral areas from 32 stations located in Tiab, Azini, Lark,  Hengam and Qeshm, Island, Bandar e pol and Bandar Khamir during the 2021 to 2022. The concentration of heavy metals showed significant spatial variations between the areas. The highest concentration of Cd 1.64±0.01 μg/g was observed at the station "Near Tabl village, South of the mangrove trees". The station "Tiab, end of the estuary" had the highest concentration of Pb 17.87±2.17 μg/g. The highest concentration of Ni 135.22±1.85 µg/g was seen in "North Tiab station, irrigation branch". The maximum concentration of metal Cr 18.41±0.41 μg/g was observed at the "Center of mangrove reservoir" station. There was the highest concentration of Zn 94.61±30.74 μg/g in "Azini Station 2" and finally, the highest concentration of Cu 40.5±0.28 μg/g was observed in the station "Khamir port, sandy bed of mangrove trees". The stations located in Tiab and the mangrove reserve had a higher intensity of pollution than other places and showed considerable risks of pollution, especially in terms of Ni and Cd. Cadmium was considered as the most dangerous metal in the studied areas which is probably caused by industrial activities. It is necessary to consider comprehensive and impressive strategies to control and reduce these heavy metal pollutions, especially in Tiab habitats and mangrove reserves where show high intensity of Cd and Ni contamination to identify, and manage the sources of these pollutions and minimize the impact of human activities on mangrove and coral ecosystems.