Journal of the Persian Gulf (Marine Science)
Volume:7 Issue: 26, Winter 2016

The study presents monthly variations of seawater properties, monitoring water column stability and stratification over the southern shelf of the Caspian Sea which depends on
collecting data. Field measurements were carried out during 13 cruises along the southern boundary of the sea. Spatial and temporal distributions of temperature, salinity and density were investigated. Monthly changes of water temperature at the sea surface (ΔT 20 C   ) were under influence of the climate changes in the region. Physical structure of water column in the southern Caspian Sea is characterized by a significant seasonal thermocline formed approximately between 20-50m depths. Water column out of the shelf was strongly stratified in midsummer (ΔT 16 C   ). Shallow water over the continental shelf was moderately well mixed. Destruction of the thermocline occurred with the general cooling of the sea surface water and deepening of the mixed layer from late of autumn to mid winter. Frequency of stability across the surface mixed layer and thermocline was more than deeper levels. Structures of thermocline and pycnocline were characterized by a significant homogeneity, especially in offshore stations during the year. Because of high correlation between density and temperature in the Caspian Seawater, a strong seasonal pycnocline was observed in the position of the thermocline. Monthly changes of physical characteristics of  seawater were mainly limited to the upper 100 m layers. Below this layer, monthly changes of seawater parameters were minor. Variations of salinity were about 12.4 during the time of measurements.

Salicornia europaea L. is a common halophytic plant species distributed in many saline soils and habitats, including margins of many wetlands. Salicornia europaea grows around Mighan Wetland, a natural desert ecosystem in central Iran with fluctuating water levels due to constant heat and severe wind throughout the year. Although, aspects of biology and ecology of halophytes growing in Mighan Wetland have been studied, information on Salicornia europaea is scarce. This research was carried out to compare both enzymatic and non- enzymatic antioxidants of Salicornia europaea L. Soil and whole plant samples were collected in triplicate four equidistant locations from Wetland edge in May, 2016. Soil samples were analyzed for its pH and electric conductivity (EC). Plant leaves were analyzed for activities of stress-related enzymatic (peroxidase and catalase) antioxidants and contents of non-enzymatic antioxidants (flavonoids and anthocyanins), cell membrane integrity via measuring lipid peroxidation through Malondialdehyde production (MDA) and changes in content of leaf saponin. Analysis of variance (ANOVA), Duncan Post-hoc tests and correlation tests were performed using the SPSS.22 statistical program. Results showed that peroxidase activity reduced and contents of total flavonoids, anthocyanin, saponin and MDA as well as activity of catalase hiked with increasing EC. The study showed that S. europaea reacts to salinity stress by restricting catalase in proxisomes to limit ROS production, accumulating carbohydrates in cytosol to improve osmoregulation and producing flavonoids, anthocyanine and saponins as complementary osmo regulators and defensive agents.

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 order to study kidney changes in, Tenualosa ilisha during migration from sea to the river, twenty mature T. ilisha specimens were collected from the Persian Gulf (42.7ppt salinity and 29.27°C temperature) and twenty specimens from Arvand River (2.3ppt salinity and 21.16°C temperature). Macroscopic observation indicated that the kidney was located retroperitoneal and attached to the vertebral column. For histological studies, 5 mm of thickness, from all parts of the kidney removed and fixed in Bouin’s fixative. Routine procedures of preparation of tissues as dehydration, clearing and embedding were followed and paraffin blocks cut at 4-6 micron and stained with Hematoxylin and Eosin. In sea and river specimens, the head of the kidney composed exclusively of hematopoietic tissue. But, in the body and caudal part, the amount of hematopoietic tissue was less and substituted by renal tubules and glomeruli. The microscopic results of kidney tubules showed that nephrons consisted of glomerulus, proximal tubules (I & II), distal tubules and collective tubules. The proximal tubules consisted of cuboidal cells with well- developed brush border. The distal tubules had cuboidal epithelium without brush border. The collecting tubules lined with high cuboidal epithelium. Their nuclei were mainly spherical and located in the central portion of the cells. Morphometric studies showed glomerular volume was larger in fish acclimated to freshwater, and tubules were larger in diameter and had thicker walls (P ≤ 0.05). On this research, we clearly demonstrate that histologic changes take place in the kidney of this marine migratory species that is acclimated to different physicochemical characteristics of sea and freshwater environments.

In this research, SPEI (standardized precipitation and evaporation index) was used as an alternative index to SPI to study drought in warm southern coastal regions of Iran. Drought has a multi-scale nature that can be analyzed in time scales via analysis of precipitation and temperature data. Therefore, data were colected from 105 synoptic stations in Iran in 2015; Respective station SPEI and SPI coding and calculations analyzed in three-month increments.and values of the SPEI and SPI compared against drought zonation patterns in Iran. Comparison of drought zonation patterns reveals that in the three seasons of fall, winter and spring, the SPI and SPEI patterns are nearly the same, but the severity of wet and dry years based on the SPI and SPEI are more pronounced in similar regions, respectively. However, in summer, the SPI and SPEI indices are very different for the central and southern coasts of Iran, specifically, for the Hormozgan and Bushehr provinces. In the central and southern regions, increased precipitation and temperature is encountered, but the SPI and SPEI indices show wet and dry years, respectively. It appears that increased temperature and intensity of evapotranspiration in the southern coastal region of the country (the Persian Gulf and Oman Sea coasts) affects the area severely and that proper precipitation in summer cannot compensate for insufficient rainfall during the previous months or years. Therefore, effects of temperature and evapotranspiration play a major role in determining the severity of dry or wet years in southern coastal regions of Iran; Thus, precipitation is not the only determinant of drought in this region.

The present study aims at the identification and investigation of fatty acid and amino acid profiles in male and female Liza aurata in the southern part of the Caspian Sea, in reproductive (autumn) and non-reproductive (spring) seasons. The results showed difference between the total fatty acids levels in the sexes. Analyses of fatty acids indicated a higher percentage of C16:0, C18:1 and 22:6 (DHA) in the SFA, MUFA and PUFA groups, respectively. The results indicated the importance of PUFA during the spring. The ratios of n-3/n-6 and FLQ in female were more than male in the spring and the amount of AI and TI was lower than 1. Besides, the amount of amino acids was higher in the spring, depending on the fish diet. However, there was no significant difference between the male and female fish with regards to amino acids; therefore, sex had no bearing on the amino acid content. Furthermore, the ratios of TEAA/TNEAA for the fish in the spring and autumn were 1 and 0.99 respectively. The ratio of leucine/isoleucine in L. aurata showed a good balance, which indicated the excellent quality of protein in this species. This information of the fillet can be used as indicators of dietary lipid, essential fatty acid and amino acid requirements of L. aurata, which may contribute to the formulation of a balanced diet for the culture of this species and depending on the fish sex.