JOURNAL OF MARINE SCIENCES AND TECHNOLOGY
Year:2018 | Volume:17 | Issue:1|Papers Count:10

In this study, two populations of Aphanius ginaonis (Holly, 1929) and Aphanius dispar (Ruppell, 1828) were examined to determine genetic diversity using PCR-RFLP technique. A total of 60 individual specimens were collected from Hormozgan and Bushehr internal waters, comprising two sampling sites; from Geno hot spring (30 individuals of A. ginaonis) and Mir Ahmad hot spring (30 individuals of A. dispar). The D-loop region of mitochondrial DNA (550 bp) was amplified using PCR followed by RFLP analysis based on 5 restriction endonucleas enzymes (AluI, DpnI, Eco47I, HindIII HinfI). In order to undertake data analysis, Arlequin 3. 11 was applied. Results at population levels indicated that Geno individuals have more haplotype diversity than Mir Ahmad individuals (9 and 3 haplotypes respectively). However, further investigation using genetic techniques is required to clarify the molecular history and evolution of Aphanius species in this area. Results obtained from this research would be applicable to understand conservation genetics and management of this important fish species in Iran.

Dust prediction such as prediction of wind and rain needs to synoptic information to the earth's surface, upper layers of the atmosphere, the prediction maps of land surface and upper levels as well as using radar and satellites. In the meantime, radar and satellite observations included remote sensing can be useful in prediction accuracy. The purpose of this study, use of remote sensing technology and MODIS images to estimate dust optical depth on the Persian Gulf surface and estimating the linear correlation relationship between the dust measurements in ground and atmospheric. The dust optical depth calculated using the code developed in MATLAB software. Evaluation of extracted data conducted using Pearson correlation coefficient, RMSE and RMSD index. In this study, optical depth obtained from image processing compared with the optical depths obtained from AERONET network. The evaluation results showed a high and significant correlation between the obtained optical depth and optical depths obtained from AERONET network (R2=0. 99). The best and most suitable mode demonstrated for 1. 243 and 1. 632 bonds. At all stations, AOD value obtained from satellite image is bigger than AOD amount corresponding to the AERONET station and the algorithm used has overestimated. The cause of this more estimate can be use of limited particle's effective radius, because the scope of this effective radius is limited at the distribution of particle size in log-normal. Error resources at the retrieving particulate matter was defined such as sensor calibration error, pollution on the radiation angle, or poor predictor of water reflection.

Taxonomic studies on the Anomura larvae of the Persian Gulf are relatively few. This research has been done on larval stage of Diogenes sp. (Anomura: Diogenidae)on coastal waters of Bahmanshir River. Anomura is a group of decapod crustaceans, including hermit crabsthat are cosmopolitan and could be found from coastal waters to 5000 m in depth. The larval stages differ among families of Anomura. Anomura larvalsamples collected by plankton net (mesh size of 300 μ m) from seven stations in February 2011 to October 2012. Planktonic larval were sampled from the Bahmanshir River in north of the Persian Gulf. The larval stages illustrated and described in detail for Diogenes sp. Finally Diogenes sp. were identified and their schematic figures were made using Camera Lucida. Maximum value of the average abundance of larvae (12. 3± 3. 4 ind. m3) was recorded in May. Also positive relationship betweensalinity with frequency of Diogenes sp. were found significantly using spearman correlation coefficients (P< 0. 05).

Feeding strategy of blue swimming crab (Portunus pelagicus) was investigated monthly in Khuzestan province water from April-2016 to march-2017. Samples were catch by trawl net. The content of P. pelagicus stomachs, percentage of occurrence frequency and Frequency percentage of feeding items was checked. In crab stomachs different feeding items group such as crustacean, mollusks, sponges, phytoplanktons, corals, fish, sand particles and etc. Was observed. The highest frequency of occurrence belonging to sponges, crustaceans and mollusks, respectively. Furthermore, Frequency percentage of sponges (38. 65%) was higher than other preys. Costello's graphical model analysis Results analysis of P. pelagicus stomach content by Costello's model showed that this crab is a predator with specific feeding nich and feeding specific prey include sponges, crustacean and mollusks during a year. Though, it's feeding pattern show few seasonally fluctuations. In this model, phytoplanktons, fish, polycheats, corals, nematode, protista, ctenophore, nematodes, cestod, sea insects and sand identified as accidental or rare prey. Probably, ingest by crab while feeding from specific prey.

In this study age, growth and maturity of Hilsa shad in Khuzestan province were analyzed. 394 number of fishes from marine habitat (Lifeh-Boseif), estuaries (Bahmanshir and Arvand) and rivers (Bahmanshir and Karoon) from February 2014 to September 2014 were collected using commercial fishing with gill net. Total length and wet weight of each fish were measured with precision of 1 cm and 1 gram. Sagittal otoliths were extracted for age determination of the fish. Since the otoliths were fragile, they were sectioned by polishing with sandpapers 800, 1500 and 2000. Then abdominal cavity of each sample were opened for determining sex and maturity stage. Growth parameters were calculated using von Bertalanffy growth function (L∞ =58. 365, K=0. 26, t0=-0. 16). Phi-prime constant was obtained 2. 95. Length and age at first maturity were obtained 27. 32cm and 2. 4 g respectively using logistic model to fit a and b parameters with observed data in spawning season.

The importance of the use of medicinal plants against infectious and non-infectious diseases is completely obvious. The replacement of synthetic drugs due to their multiple properties in the prevention and treatment of many diseases, particularly in the aquaculture industry seems to be very important. This study was performed with the aim of assessing the acute toxicity (LC50-96) of thyme essential oil on rainbow trout. To study the effect of the essential oils, 80 premature rainbow trout with an average weight of 10± 0. 5 in 9-liter tanks were exposed to different concentrations of essential oils of thyme and daily losses based on OECD protocol were calculated during 96 hours. All the physical and chemical factors such as water temperature, dissolved oxygen, pH, nitrite, nitrate, ammonium levels, electrical conductivity and water hardness were measured in different treatments. The acute toxicity of the essential oil of thyme was calculated using Probit analysis and a concentration of 4. 4 ppm was determined.

Seasonal and annual variability in circulation of surface waters of the Caspian Sea were studied using POM model. In this model, temperature and salinity field’ s data and wind field and the flow of atmospheric data were collected from WOA and daily data bank ECMWF, respectively, with a resolution of 5. 7 minutes and the time step of 6 hours and for Bathymetry from GEBCO08 data with a resolution of 30 seconds is used. Initially, the model for ten years (1988-1997) was carried out and, after examining the stability of the model with measurement data available (1996) were compared, that good agreement between their temperature and salinity changes observed. Then, for the last ten years (2005-2014) in two cases (with and without taking into account the flows of atmospheric wind field data and rivers) model was implemented. The results showed that changes in water flow in all seasons, in shallow areas, wind field indicates the dominant effect on the region, but in deep, wind has less effect on the flow. According to the seasonal circulations, wind force in the northern basin and shallow areas the Caspian Sea are more effective in the formation of water flows.

Shadegan wetland as largest wetland in Iran constantly exposed to hydrocarbons entering through the main entrance of the lagoon, including Jarahi river, outbursts of seasonal rivers from upstream, Persian Gulf tides from downstream, atmospheric deposition and possible leaks from oil pipelines. Considering importance and extent of wetland and multiple sources of hydrocarbons, the aim of present study is to identify source and mapping of spatial distribution of polycyclic aromatic hydrocarbon (PAH) and n-alkanes using Geostatistics techniques. Sediment samples collected at 202 stations at the top 5 cm of the sediment according to a systematic-random sampling design to cover whole wetland. The concentrations and compositions of hydrocarbons were analyzed by GC– MS. The spatial distribution of PAH for concentration and source mapped using total PAH and MP/P (Methylphenanthrene/Phenanthrene) index, respectively. Map of spatial distribution on concentration and Source of n-alkanes made based on total n-alkanes and CPI index, respectively. The ordinary kriging method applied for Spatial variability and interpolation of data in geostatistical study using GS+ and Arc GIS. Firstly, normality of data was determined by using Kolmogorov – Smirnov test and after semi-variogram calculation, Spherical, Exponential and Gaussian models were fitted to each of heavy metals. RMSE parameter of Cross-Validation was used for model validity. The results of mapping analysis indicated that Shadegan wetland were strongly contaminated by petrogenic hydrocarbon source and 90% of the study area is subjected to chronic pollution of oil contaminants.

One of the ways to control the erosion in the outer bend of rivers is to use spur dikes. In recent years, the efficiency, affordability and environmental suitability of traditional spur dikes has been criticized. Therefore the importance of adopting methods which are both cost-effective and eco-friendly has been addressed. The bandal-like spur dike is a combination of a permeable and an impermeable spur dike, which is usually used in Indian Sub-Continents for riverbank protection and improvement of navigation conditions in alluvial rivers. It is made of bamboo therefore it is inexpensive and environmental friendly. In this research the effect of the permeability percentage of the bandal-like structure on the maximum scour depth around it in a 90 degree mild bend flume and in submerged condition is investigated. Therefore a series of impermeable spur dikes (0% permeability) and bandal-like structures with (33, 50 and 64) percent permeability are placed in the flume and examined under four different Froude numbers (0. 21, 0. 23, 0. 26, 0. 29). The results showed that the maximum scour depth around the bandal-like structure is considerably less than the maximum scour depth around impermeable spur dikes. Also by increasing the permeability percentage of the bandal-like structures the maximum scour depth around it decreases.

In designing of a marine vehicle, derivation of hydrodynamic coefficients of the equations of motion is very important. For derivation of these hydrodynamic coefficient's various methods such as analytical-experimental methods, Computational Fluid Dynamic (CFD) method and model test can be used. Among These methods, due to the limitations of analytical-experimental methods and computational fluid dynamic method, the most accurate method is model testing. Empirically derived coefficients, which obtain in the marine laboratory, use to simulate the behavior of a marine vessel in the International Maritime Organization (IMO) maneuver test and determine the vessel's maneuverability. Due to differences in the marine laboratory equipment and test methods and to ensure the accuracy of results, standard models are tested and the results are compared against the results provided by the International Towing Tank Conference (ITTC). Accordingly, this article describes the process of model testing and derivation of the coefficients for the Esso Osaka benchmark vessel, using static and dynamic testing with Horizontal Planar Motion Mechanism (HPMM) in Shohada-e-Khalij-e-Fars national marine laboratory and compare the results with the results provided by the international towing tank conference.