An updated checklist of marine gastropods of the Persian Gulf and Gulf of Oman.

Calibration and skill assessment of two input and dissipation parameterizations in WAVEWATCH-III model forced with ERA5 winds with application to Persian Gulf and Gulf of Oman

Functional composition of Chaetodon butterflyfishes at a peripheral and extreme coral reef location, the Persian Gulf

Extremophile symbionts in extreme environments; a contribution to the diversity of Symbiodiniaceae across the northern Persian Gulf and Gulf of Oman

Estimation of plastic waste inputs from land into the Persian Gulf and the Gulf of Oman: An environmental disaster, scientific and social concerns

The Persian Gulf and the Gulf of Oman locate at the northwest of the Arabian Sea, with the total area more than 50,0000 km2. The Persian Gulf is a semi-enclosed subtropical sea with high water temperature, extremely high salinity, and an average depth of 50 meters. By the Strait of Hormuz, the Persian Gulf is connected to the Gulf of Oman which is significantly affected by the monsoonal winds and by water exchange between the Arabian Sea and the Persian Gulf. Algal blooms occurred frequently in the Persian Gulf and the Gulf of Oman, and some of them are harmful algal blooms which may lead to massive fish death and thereby serious economic loss. Due to the widely spatial coverage and temporal variation, it is difficult to monitoring the dynamic of the algal bloom based on in situ measurement. In this study, we used the remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to investigate a massive algal bloom event in the Persian Gulf and the Gulf of Oman during 2008-2009. The time series of MODIS-derived chlorophyll concentration (Chl-a) indicated that the bloom event with high Chl-a concentration (~60 percent higher than corresponding climatological data) appeared to lasting more than 8 months from autumn of 2008 to spring of 2009. In addition, the bloom was widespread from the Persian Gulf to the Gulf of Oman and neighboring open ocean. The MODIS-derived net primary production (NPP) collected from MODIS showed the same trend with Chl-a. Multiple forces including upwelling, dust deposition was taken into account to elucidate the mechanisms for the long-lasting algal bloom. The time series chlorophyll concentration of the Persian Gulf emerges a significant seasonal pattern with maximum concentrations seen during the winter time and lowest during the summer. It also indicated slight disturbances occurred in June (May/July) and December (November/ January) in some years. The sea surface temperature and water transparency in the Persian Gulf increased with the rates of 0.3% (<0.01) and 3.02% (p<0.01) during 2003-2014, respectively. Chl-a and NPP declined with the rates of 1.61% (p=0.06) and 1.09% (p=0.08), respectively. However, there are no significant changes of the bloom initiation, termination and duration time among years over 2003-2014.

The balanid barnacle, Amphibalanus amphitrite, is known as one of the most common fouling species in the world. A phylogenetic study using material from around the world recovered three distinct clades for this species. Material from the Persian Gulf (PG) and the Gulf of Oman (GO) were not included in that survey. In the present study, we aimed to assess the genetic diversity of the balanid barnacles of these two gulfs and to evaluate their phylogeography. In total, 94 COI DNA sequences were obtained from the PG and the GO material. Most of these sequences clustered into a single clade, corresponding to clade I of the previous global study. However, two sequences, one from the PG and one from the GO, fell into a separate clade corresponding to clade III of the previous study. These two gulfs share some common haplotypes, but host several unique ones that are separated from the most common haplotype mainly by a single mutation. Based on various indices, the genetic diversity of the PG material was higher than that of the GO. Low values of ΦST show a regular gene flow among the stations and the two gulfs. The Bayesian skyline plots and the mismatch distribution analyses both showed signs of a recent population expansion in the PG and the GO. We also modeled the potential distribution areas for A. amphitrite to reveal the separate suitable habitats for the clades. The current phylogeographic status and genetic diversity of A. amphitrite in the PG and GO appears to have been shaped by both historical events and recent human activities.

Currently, only 31 nereidid species are known from the Persian Gulf and Gulf of Oman. The present study was carried out in order to investigate the poorly known diversity of nereidid polychaetes from seas of the southern coasts of Iran. Specimens were collected from 23 locations along the intertidal zones of the two water bodies. Among the 26 species found: two are new, and are described here, including Simplisetia qeshmensis sp. nov. and Neanthes biparagnatha sp. nov.; 11 are new geographical records. Neanthes biparagnatha sp. nov. is most similar to N. deplanata (Mohammed, 1971), which is also found in the Persian Gulf, but can be most easily distinguished from it by the presence of bars in addition to cones in Area IV of the pharynx. Simplisetia qeshmensis sp. nov. may be distinguished from its closest congener, S. erythraeensis (Fauvel, 1918), also reported from the Persian Gulf, by having a greater number of paragnaths in Area I of the pharynx, an additional type of chaeta (homogomph spinigers) in the ventral neuropodial fascicle and having a reduced notopodial lobe in posterior chaetigers. The list of new records includes: one species from both areas, Neanthes glandicincta (Southern, 1921); eight species from the Persian Gulf, Leonnates decipiens Fauvel, 1929, Neanthes acuminata (Ehlers, 1868), Neanthes sp., Neanthes sp. cf. N. acuminata, Nereis sp. cf. N. pelagica Linnaeus, 1758, Perinereis cultrifera (Grube, 1840) species complex., Pseudonereis trimaculata (Horst, 1924), Pseudonereis sp. cf. P. variegata (Grube, 1857) and two from the Gulf of Oman, Leonnates persicus Wesenberg-Lund, 1949 and Perinereis kuwaitensis Mohammed, 1970. The present study brings to 40 the number of nereidid species currently known from the Persian Gulf and Gulf of Oman. A taxonomic key to nereidid species from the intertidal zones of the Persian Gulf and Gulf of Oman is presented to facilitate future investigations.

Background. Although several researchers have examined otoliths of marine fishes from the Persian Gulf and the Gulf of Oman, none has reported abnormalities. A recent effort to identify stocks of marine fishes of the Persian Gulf and the Gulf of Oman revealed that several species have abnormal otoliths. This is the first study reporting and describing the occurrence of abnormal otoliths from the fishes collected from the Persian Gulf and the Gulf of Oman. Materials and methods. A total of 225 fish specimens belong to 83 species and 33 families were randomly sampled from the Persian Gulf and the Gulf of Oman. The standard lengths (SL) were measured to the nearest 0.5 mm. The otoliths were extracted, cleaned, and described following available literature. The specimens and their otoliths were deposited in the Zoological Museum at Shahid Bahonar University of Kerman (ZM-SBUK). Results. Among the studied 83 species, we found six species having abnormal otoliths (4.8% of the studied specimens). They belong to six families; Carangidae, Chanidae, Chirocentridae, Leiognathidae, Paralichthyidae, and Sparidae. The number of specimens with abnormal otoliths only in one side (either right or left side) was six, and those with abnormal otoliths in both sides was five. The left otoliths presented more extreme changes than the right. The observed abnormalities can be classified into three types; asteriscus attached to sagittal (the most common); otoliths with a more translucent or crystalline appearance in surface or outlines; and those with an abnormality in their sulcus region. Conclusion. Ecologically, the Persian Gulf is an environment having various kinds of stresses such as salinity fluctuation, acidification, and the water temperature. Such stressors probably affect otolith formation during the larval stages of these fishes and are responsible for the observed abnormalities.

Late Pleistocene and Holocene sedimentation in the Persian Gulf—Gulf of Oman

Variations in environmental factors can alter the species distribution pattern in intertidal rocky shores. The Persian Gulf (PG) and the Gulf of Oman (GO) vary substantially with respect to environmental and oceanographic conditions. The abundance and biodiversity of intertidal rocky gastropods in five locations across the northern PG and the GO were compared, and the environmental variables underlying the distribution pattern of these organisms were investigated. A total of 67 gastropod species were identified. The largest average density (294 ind./m2) and diversity (N = 43) for gastropods occurred in the Hotel Lipar station (LIP) located in Chabahar Bay in the GO. Clypeomorus bifasciata (107.43 ind./m2) followed by Cerithium caeruleum (94.67 ind./m2) were the most abundant species. Planaxis sulcatus and Siphonaria spp. occurred in all locations during both sampling occasions. Species richness and abundance of gastropods showed significant differences between LIP and remaining locations. A significant difference was found in assemblage structure across locations. In general, the species richness and density in the locations at GO were significantly larger than those locations in the PG, suggesting that the harsh environmental condition in the PG might be the forcing factor for this diminish. Distinct grouping was observed in both assemblage structure and species composition between locations in the PG and the GO. The spatial and temporal distribution patterns of gastropods assemblages were significantly correlated with variation in salinity and substrate rugosity.

Distribution and abundance patterns of rocky intertidal fish assemblages in the Persian Gulf and Gulf of Oman were examined. Specimens were collected at low tide from tide pools, using chlorine as an ichthyocide. A series of collections undertaken between May and July 2006 at 6 stations yielded 1497 fishes, comprising 20 species from 8 families. Permanent tide pool residents (Gobiidae and Blenniidae) comprised 93.5% of the total fish assemblage; secondary residents comprised the remaining 6.5%. The most common fish species were Antennablennius variopunctatus (Blenniidae; 23.4%), Istigobius ornatus (Gobiidae; 19.8%), Bathygobius meggitti (Gobiidae; 18.7%) Cryptocentroides arabicus (Gobiidae; 10.5%), Istiblennius pox (Gobiidae; 7.3%), and Omobranchus fasciolatus (Blenniidae; 6.8%). The results of the present study revealed that, compared to the Gulf of Oman, diversity indices in the Persian Gulf are low. Although Qeshm Island is located in the Persian Gulf, the diversity indices are high at this station most probably due to enhanced contact with the adjacent open ocean, the Gulf of Oman. Hierarchical cluster analysis indicated that the Persian Gulf stations are more similar to each other than to the stations located in the Gulf of Oman.

Reef-building corals are in obligate symbiosis with dinoflagellates of the family Symbiodiniaceae. The partnership, however, is prone to breakdown as a result of thermal stress, which leads to coral bleaching. According to the Adaptive Bleaching Hypothesis, corals’ recovery from bleaching is profoundly influenced by forming stable associations with thermotolerant algal strains during bleaching. Consequently, the knowledge of the diversity of host-symbiont associations during this period is substantial. Since the extent of symbiont shuffling varies among different host taxa, we investigated the diversity of dominant Symbiodiniaceae in association with the scleractinian coral Dipsastraea pallida before and after massive bleaching events of 2017 in the Persian Gulf and 2018 in the Gulf of Oman. We observed a flexible association between D. pallida and five lineages of Symbiodiniaceae (i.e., ITS2-types A1.4, C3, C39, D1a, D5) with a clear regional pattern. However, the pattern of these associations was changed following bleaching events, with the complete replacement of Cladocopium-C39 by Durusdinium-D1a in the Gulf of Oman, and increased proportion of Durusdinium-D1a and disappearance of Symbiodinium-A1.4 in the northeastern Persian Gulf. In the westernmost Persian Gulf, on the other hand, a stable D. pallida-Cladocopium-C3 partnership was observed. These findings convey the potential of D. pallida to shift the prevalence of its symbiont communities within a population in response to bleaching, which may reflect symbiont shuffling and/or differential mortality and partly explain the predominance of Dipsastraea corals in the Persian Gulf and Gulf of Oman.

A 2D hydrodynamic model, with ability to use unstructured triangular grids, was used to evaluate wind-induced sea level variations in two important gulfs in the Middles East. The model was forced by the modified QuikSCAT wind data above the sea level for a 10-years period, (from 1999 to 2009). Measured water levels at Kish and Lavan Islands were used to calibrate and verify the model. A special effort was carried out to eliminate tidal levels data from the measurements to obtain raw wind-induced fluctuations. The wind drag coefficient, used as main calibration factor was estimated as a function of wind speed. The results proved that the wind drag coefficients for this area are much greater than those which are used in open-oceans. Comparison with the field data proved that the wind-induced setups in the Persian Gulf are much greater than those which were predicted in the previous studies. The final results show that the model is completely applicable for the development of an operational system for predicting wind-induced extreme sea levels in the Persian Gulf and The Oman Sea. In this paper, the wind-induced extreme levels were determined for different coastal areas in the Persian Gulf and the Gulf of Oman. In addition, two useful maps were developed to present extreme wind setup and set-down throughout 10-year modeling period for entire the Persian Gulf and the Gulf of Oman. The results show that extreme wind-induced water levels, in the Northwest and Southeast of the Persian Gulf, are much higher than other places in this region.

The marine environment of the Persian Gulf is characterized by extreme biophysical factors, like high salinities. This gulf is a semi-enclosed basin and is connected to the Gulf of Oman via the narrow Strait of Hormuz that may act as a barrier to gene flow between the two gulfs. Consequently, animal populations living in the Persian Gulf are hypothesized to be isolated and thus to evolve independently from neighbouring populations. We tested this hypothesis with the xanthid crab,Leptodius exaratus(H. Milne Edwards, 1834), which is one of the most common intertidal crabs occurring in the Persian Gulf and the Gulf of Oman. Four-hundred-and-fifty specimens were collected from eight sampling sites, i.e., four sites each in the Persian Gulf and the Gulf of Oman. Fifteen morphometric characters were measured. Males and females were analysed separately to avoid bias as a consequence of sexual dimorphism. Due to the lack of normal distribution in males, two different approaches were carried out in this paper. Female specimens were included in parametric analyses, while males were tested with permutational multivariate analyses of variance. In female morphometric characters,t-test analyses showed significant differences between the two sets of populations, and the discriminant analysis showed divergence between the two groups (with 83% correct groupings). In the males, the applied analyses showed a significant difference () between the two gulfs. These divergences can be interpreted as a consequence of regional adaptations and a low rate of larval migration between the two gulfs.

Climate change’s effect on sea surface temperature (SST) at the regional scale vary due to driving forces that include potential changes in ocean circulation and internal climate variability, ice cover, thermal stability, and ocean mixing layer depth. For a better understanding of future effects, it is important to analyze historical changes in SST at regional scales and test prediction techniques. In this study, the variation in SST across the Persian Gulf and Gulf of Oman (PG&GO) during the past four decades was analyzed and predicted to the end of 21st century using a proper orthogonal decomposition (POD) model. As input, daily optimum interpolation SST anomaly (DOISSTA) data, available from the National Oceanic and Atmospheric Administration of the United States, were used. Descriptive analyses and POD results demonstrated a gradually increasing trend in DOISSTA in the PG&GO over the past four decades. The spatial distribution of DOISSTA indicated: (1) that shallow parts of the Persian Gulf have experienced minimum and maximum values of DOISSTA and (2) high variability in DOISSTA in shallow parts of the Persian Gulf, including some parts of southern and northwestern coasts. Prediction of future SST using the POD model revealed the highest warming during summer in the entire PG&GO by 2100 and the lowest warming during fall and winter in the Persian Gulf and Gulf of Oman, respectively. The model indicated that monthly SST in the Persian Gulf may increase by up to 4.3 °C in August by the turn of the century. Similarly, mean annual changes in SST across the PG&GO may increase by about 2.2 °C by 2100.