Journal of the Persian Gulf (Marine Science)
Volume:8 Issue: 29, Fall 2017

Observations from an eight-year ocean station at Chabahar showed that both salinity and electrical conductivity (EC) have increased over the past nine years. Meanwhile, pH remained at steady state levels and there was no significant trend in mean annual temperatures. The best repeating pattern of monthly oscillations was depicted in temperature data with the highest and the lowest temperatures occurring at 4th/ 5th and 10th/ 11th months, respectively. Changes in salinity/EC and temperature were moderately correlated. The mean monthly pH levels rarely fell below 8.00. There were no signs of hypoxia during the study period.

The Investigation of the changes in sea level, which directly affects various industries, such as shipping, fishing and power plants, is of great importance in environmental studies. As the largest enclosed water body in the world, the Caspian Sea is one of the most important water resources and has a significant impact on the environment and lives of its neighboring countries’ people. In this regard, determining variations of mass distribution of the Earth through gravimetric data can be helpful in monitoring Caspian Sea level fluctuations. Accordingly, in this study, the Caspian Sea level fluctuations from 2003 to 2017 were investigated using the Gravity Recovery and Climate Experiment (GRACE) monthly mass grids. This product includes three equivalent water thickness bands, produced by the Center for Space Research (CSR), GeoForschungsZentrum (GFZ), and Jet Propulsion Laboratory (JPL). Since, these three bands were processed independently, some differences may exist between their results, therefore, it is more reliable to consider all of them. The investigations indicated that in a point in the center of the southern Caspian Sea, the fluctuations were between -42.5 and 26 cm. In a point in the southwestern part of the study area, the fluctuations were in a range of -42.7 cm and 22.5 cm. Also, the fluctuations varied between -37.1 and 23.1 cm in a point in the southeastern part of the Caspian Sea. Furthermore, it can be inferred from our investigations that changes in water level are due to seasonal changes, climate change and irregular dam building on rivers flowing into the sea.

In this study, the changes in nutrient concentration, chlorophyll a, total alkalinity and physicochemical parameters of surface water at mangrove and marine stations in Nayband mangrove ecosystem were investigated. Water samples were collected from 4 stations distributed throughout the mangrove forest and 3 stations in the coastal water of the Persian Gulf during two seasons of summer and winter. The results showed that the average of salinity and temperature at mangrove stations in the summer was significantly higher than the winter and the mean pH and dissolved oxygen in the winter was significantly higher than the summer (p<0.05). Statistical comparison showed that mean concentration of phosphate, silicate, chlorophyll a and total alkalinity in surface waters of mangrove forests in the summer was significantly higher than the winter (p<0.05), and mean concentration of nitrite, nitrate and ammonium in the winter was significantly higher than the summer at mangrove stations. In addition, the statistical comparison showed that the mean concentration of nutrients (phosphate, silicate, nitrite and ammonium) and chlorophyll a at mangrove stations was significantly higher than marine stations (p<0.05) in both seasons.

Application of numerical models is useful in coastal sediment studies; however, it is essential to calibrate the models in an appropriate method. Empirical equations, historical satellite imagery and other coastal data and evidence are proposed for the models calibration in the vicinity of coastal indicators around the site of projects.In this study, coastal sediment process of Kuhmobarak area is investigated to evaluate construction of a new port at the southeast of Hormozgan province. For this purpose, a comprehensive study on effective parameters is performed to describe sediment process of the area. Furthermore, numerical models of sediment transport calculation and morphological evaluation are calibrated using the suggested organized methodology.

In the current study, the intertidal amphipod assemblages of two Iranian Islands which includes Qeshm ,  as an Island near to mainland, and Abu Musa, as an Island far from the mainland. The sampling is down in eight stations in each Island from 2013 to 2016. Results show that the amphipod assemblages of Abu Musa  and Qeshm islands were composed of 8 species from 8 genera and 5 families and 11 species from 11 genera and 6 families, respectively.  The record of the Glossomaera octodens (Sivaprakasam, 1968) is new for the western part of the Indian Ocean. There were no differences in taxonomic indices between islands. However, both islands showed similar average taxonomic distance with greater variation in taxonomic distance and species richness [a1] of Qeshm  compared with Abu Musa, primarily because of .greater   variation in habitats in the former. The better environmental conditions in Abu Musa caused higher abundance per species then in Qeshm. The results of the present study add two species to previous reports of the Abu Musa Island and produce first comprehensive listed record of amphipods in the Qeshm Island, including new species record.

The involvement of adrenergic and dopaminergic receptor subunits are recognized in regulating fish repoduction. The potential for neuroendocrine novel pharmaceutics to induce final maturation and ovulation has not been well studied. The aim of the present study was to investigate the effects of new catecholamine pharmaceutics at different doses, including clozapine and olanzapine (the third generation of D4 and D2 dopamine receptor antagonists, respectively), which could be more effective than the first and second generations, salbutamol (β2-adrenergic receptor agonist) and metoprolol (β1- adrenergic receptor antagonist) as compared with ovaprim (D-Ala6,Pro9-Net)-sGnRH+Domperidone, on final oocyte maturation (FOM), ovulation and spawning in Rutilus frisii kutum. In the present investigation, 126 gravid females were injected once with ovaprim, 0.5mlkg-1 BW, salbutamol sulphate (SLB) 2, 4 or 8 mg kg-1 BW; metoprolol tartrate (MTP) 5, 10 or 20 mg kg-1 BW; olanzapine (OLZ) 2, 5 or 10 mg kg-1 BW; clozapine (CZ) 2, 8 or 12 mg kg-1 BW (N=9), been divided into 14 groups. Intact and ovaprim were negative and positive Control groups respectively. The results showed that all fish dosed with 0.5 ml kg-1 of ovaprim ovulated within 13 hours after injection,while no fish ovulated in negative control group (Intact). The parameters include ovulation index, fertilization success, relative fecundity and the number of eggs which were the highest mean values belonged to ovaprim treatment. Ovulation succes (100%) was obtained in OLZ 5 mg kg-1, CZ 12 mg kg-1, MTP 5 mg kg-1 and SLB 4 mg kg-1 treatments. Therefore, it could be concluded that SLB 4 mg appears to employ β2-adrenoceptor mechanisms in mediating the considered effects. In contrast, MTP at high doses (10 mg and 20 mg) significantly inhibited the stimulatory effect of adrenergic system on FOM and ovulation. The stimulation by the blocker (MTP) was higher in the low dose, 5 mg kg-1. The successful spawning using CZ 12 mg and OLZ 5 mg are important steps in the expansion of the culture of Caspian kutum.