This study concentrates on the 61tidal constituents of 17stations on the north of Oman Gulf(OG),Strait of Hormuz(SH)and Persian Gulf(PG).Five-years tidal data(2014-2018,30-minutes intervals) was achieved by Iran National Cartographic Center to calculate mean levels of stations.Then,t_tide library was used to calculate 61 tidal constituents by 95%of confidence in Matlab for 2018 data.Then, they sorted by the magnitude of the amplitude to express the most significant ones in each stations. Results shows that the mean levels of the northwest and northeast of PG are mirror images.Although the major diurnal and semidiurnal tidal constituents of 11stations areM2,K1,S2andO1,by changes in order of importance; in 6stations,N2 constituent is more important than O1. These exceptions go back to the stations of SH and northwest ofPG, which shows the importance of the SH bending and the shallowing of the northwest of PG. Moreover, the top ten components of all stations are not 10 unique components and they include 21 components.Due to the Form factor,F,all the studied stations are mainly mixed semidiurnal type. The predicted t-tide tides show small errors compare with the original ones. The results also showed that the range and components of harmonic astronomical tides are influenced by local geography. On the head of PG,the EmamKhomeini’s tides is sharp due to the shallow water, and the semidiurnal components(S2andN2)are much stronger than the diurnal components(O1andP1).The Pol Port’s tides is effected by narrowing of SH.Therefore, in some ports, non-tidal parameters such as geographical shape or shallow water are effective while considering astronomical components of moon and sun.

In Gulf of Oman, the sinking of Persian Gulf Water mass has been reported. In the current study, the FVCOM ocean model has been used in 20 layers to investigate the phenomenon of downwelled Persian Gulf Water in the Gulf of Oman. The bathymetry of the simulated area (47˚-59.45˚E, 22˚-32˚N) was achieved from GEBCO-2019 by the resolution of 30 seconds. Triangular grid was generated in SMS. The open boundary fluctuations were also extracted from TMD. The temperature and salinity were obtained from the output of HYCOM (standard depths). Satellite data were used for the verification. The results showed the downward vertical velocity of Persain Gulf Water is higher in the area of the sudden depth change than the other parts in all seasons. This fact indicated the downwelled water was in a form of a spot. The rate of downwards penetration of water was different (winter: -2cm/s, spring: -1cm/s, summer: -1.2cm/s, autumn: -1.7cm/s). In summer, the salinity contours were very close to each other in the east of the Strait of Hormuz, or intense stratification. Therefore, the slope of the salt wedge was less. In winter, the calculated slope of the salt wedge (1.5×10-1 degrees) was greater than summer (3.8×10-2 degrees). The larger angle or slope of the salt wedge means the greater horizontal component of the weight of water (mgsinθ). It causes the displacement of saline water, and faster movement of Persian Gulf Water. Therefore, the water of the Persian Gulf moves faster to lower depths in Gulf of Oman in winter than summer

The present study provides the first large scale survey on intertidal ichthyofauna along the coastline of Iran from Gawater Bay (Border of Pakistan) in the Gulf of Oman to ArvandKenar (Border of Iraq) in the Persian Gulf. This study was carried out in the years 2005-2006 at 15 stations, including mangrove, mudflat and rocky shores. Specimens were collected at low tide from tide pools, using chlorine and hand net. Although 36 species from 15 families were collected only 17 species including Alticus kirkii, Antennablennius bifilum, A. variopunctatus, Istiblennius edentulous, I. pox, I. spilotus, Parablennius opercularis, Omobranchus fasciolatus, O. mekranensis, O. punctatus, (belong to family Blenniidae) and Boleophthalmus dussumieri, Periophthalmus waltoni, Scartelaos tenuis, Acentrogobius dayi, Bathygobius meggitti, Cryptocentroides arabicus and Istigobius ornatus (belong to family Gobiidae) were regarded as permanent residents.

Background and Objectives: The Gulf of Oman, with an area of about 94000 km2 and a maximum depth of more than 3000 m, is located between latitudes 22 and 26 degrees of north and longitudes 56 and 62 degrees of east. This gulf plays the role of a waterway that connects the Persian Gulf to the Indian Ocean and is the place where the saline water of the Persian Gulf is exchanged with the less salty water of the Indian Ocean. This research aims to investigate the Persian Gulf Water mass (abbreviated as PGW) in the Gulf of Oman and investigate its seasonal changes. Methods: In order to identify PGW, in the studied area, the international temperature and salinity data set of the World Ocean Atlas with the abbreviation WOA18 and the spatial accuracy of 0. 25° longitude and latitude at the depths of zero, 150 and 300 meters were used seasonally. The surface maps were ploted for the mentioned depths in Ocea Data View (ODV) software. A vertical cross section map was also illustrated in the middle of the Gulf of Oman to determine the thickness of the PGW, the extent of its expansion, and the depth of its placement (based on the salinity line of 36. 45 psu). Findings: The results show that the density on the surface is mostly a function of temperature. Winter is the coldest (23. 24˚C) and densest (25. 12 kg/m3) season and summer is the warmest (32. 42˚C) and least dense (22. 41 kg/m3) season in the surface layer. Summer experiences the highest and lowest salinity at the surface (36. 45 psusurface<36. 66 psu) and at a depth of 150 m (36. 12 psu150 m<36. 45 psu). On the contrary of the surface layer, where winter is a cold season and summer is the hot season, at the depth of 150 m, summer is the cold season and winter is the hot season, which can be attributed to the differences of the seasonal thermocline up to the depth of 150 m. At the depth of 150 m, the density pattern in summer and autumn is a function of salinity, but in spring and winter, the density pattern is a function of temperature. In addition, in summer, sub-mesoscale high-pressure cyclones near Muscat can be seen on the surface, which are not clearly seen in other seasons. Also, the results clearly show that PGW is not seen in the surface layer and flows subsurface from the southern side of the Strait of Hormuz towards the Gulf of Oman. The depth of placement and extent of PGW has seasonal and spatial changes, and by moving eastward in all seasons, the thickness of PGW decreases due to mixing with the surrounding waters. The results obtained from the vertical cross section AB, in the middle of the bay, show that PGW is observed during different seasons from the depth of 150 to 375 meters, which is shallower in spring and summer and has less depth buoyancy than in autumn and winter. In the side results of this research, several fronts such as Ras Al-Had, Fins and Al-Ramis were observed in the quantity of temperature, salinity or density, which had seasonal changes. These fronts were especially noticeable in layers such as 150 m and 300 m depth because the existence of subsurface fronts is less reported in the region. Also, the results of the research showed dense and less dense cores, some of which are formed due to the eddies in the area and others due to the hydrodynamics of the area. For example, the low salinity core (13. 36 psu) near Chabahar can be due to the occurrence of the upwelling of the area, which brings the less saline waters of the middle of the gulf to the surface and causes a decrease in salinity. Conclusion: The results of this research clearly showed that PGW has seasonal changes and is located at shallower depths in spring and summer than autumn and winter. Examining the same surface maps, especially at the depth of 150 m, showed that PGW, in addition to the southern coast, can also be seen on the northern coast, which requires a more detailed investigation regarding the possibility of its presence on the northern coast or its multiple branches.

Shortly after gulf war (G.W) thousands of war veterans referred with sign and symptoms of an unknown disease called G.W illness. Despite multiple studies undertaken by several non-governmental and governmental centers this illness remains unclassified and can not be coded by international classification of disease (I.C.D). The etiology has not been found and the illness appears to be multifactorial and basically related to use of depleted uranium (D.U) weapons, chemical warfare (C.W) and biological agents. This article reviews this illness and the adverse effects of D.U and B.c.W agents in the G.W battlefields.

Corynomorpha prismatica (J. Agardh) J. Agardh (Corynomorphaceae- Florideophyceae) is reported from the intertidal of Bandar Lengeh (Hormozgan province) in the Persian Gulf and Bandar Chabhar (Sistan and Baloochestan province) in the northern Gulf of Oman. The species is a new record for both the Persian Gulf and the Gulf of Oman.  

Batch experiments were conducted to study the ability of marine algae collected from Oman Gulf, Iran, for sorption of cobalt from the metal nitrate solution. The biosorption experiments were performed using native and chemically pretreated sun-driedbiomass of marine algae. Our finding indicated that MgCl2 pretreated Cystoseria indica, Sargassum glaucescens and Padina australis had more sorption capacities, while the CaCl2 pretreated ones showed lower capacity (comparing with non-treated native biomass). Also, a fall in the cobalt uptake capacity of Nizimuddinia zanardini, Gracilaria corticata, G. arcllata, Botryocladia leptopoda, Scinaia camosa, Hypnea valentiae, VIvafasciata and Codium sp. took place after treatment with chemicals, including CaCl2 (0.1 M), MgCl2 (0.1 M), Ca Cl2 (0.1 M)/HCl (pH 2) and HCl (0.1 M). Biosorption of cobalt Was rapidly took place onto algal biosorbents and most of the sorbed metal ion was bound in the first minutes of contact. Uptake of cobalt was pH-dependent and the most cobalt removal occurred at pH 4. In our screening investigations, brown algae (Dictyota indica, N. zanardini, P. australis, S. glaucescens, and C. indica) removed cobalt most efficiently from aqueous solution, respectively. The capability of marine algae for separationof 60Co was tested and a high 60Co removalwas demonstrated.

This paper presents information on the Iranian halacarid fauna providing the first record of the genus Rhombognathus from the Gulf of Oman. Two species of the genus Rhombognathusare described from the Iranian coast, viz. Rhombognathus scutulatus Bartsch 1983 and R. iranius sp. nov.

The meiobenthic harpacticoids of the Persian Gulf and the Gulf of Oman has been almost unknown. During October 2014 to September 2016, interstitial and phytal harpacticoids were collected from tide pools in 30 different localities along the Iranian coast of the Persian Gulf and the Gulf of Oman. The new information on the distribution of 26 species and 12 families is provided, here. The most species-rich family was Laophontidae with seven species, followed by Miraciidae with four species. In this paper, all the species were considered new records for the area. Furthermore, the first checklist of meiobenthic Harpacticoids is provided.