فهرست مطالب
Journal of the Persian Gulf (Marine Science)
Volume:2 Issue: 5, Fall 2011
- تاریخ انتشار: 1390/11/16
- تعداد عناوین: 7
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Page 9Distribution, population and reproductive biology of Uca sindensis were studied in a subtropical mangrove of Pohl port in the northern Persian Gulf. Sex ratio, distribution, population structure, handedness (evenness), diameter burrow, breeding season and fecundity were investigated. Ten 0.5 m2 quadrates were randomly sampled during low tide periods from October 2009 to September 2010.A total of 711 crabs, 344 (47.7%) males and 367(52.3%) females, were sampled. The CW of males ranged from 4 to16 mm and of females from 5 to 17 mm indicating sexual dimorphism. The overall sex ratio was 1:0.93 and did not differ significantly from the expected 1:1 (χ test, P>0.05), however the monthly sex ratio was different from expected 1:1(χ test, P<0.05). Results indicated that the size frequency distributions of this species could also be determined through direct analysis of burrow openings (r2=0.99). Breeding took place during warm season of April 2009 to September 2010. Egg numbers increased with female size(r2=0.50). The regression analysis showed that the number of eggs increased linearly with the increase of carapace width (r2= 0.766, EN= 0.1125 CW-0.1129, n=31). It was concluded that two factors of temperature and TOM affected growth and reproduction pattern in U. sindensis.
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Page 17The study presents the result of a new attempt for benthic biotopes remote sensing in the southern coast of the Qeshm Island in the Persian Gulf. This survey site covers approximately 233 km2 in water depth between five and 25 m. Bathymetric data was derived from the single beam survey and grab stations, underwater video and photos were undertaken as ground-trusthing. The acoustic results showed the survey occurred in shallow waters. Sediments were classified as muddy and into six types following Went-Worth scale. In total, 214 species belonging to 91 families, 48 orders and 20 classes were identified. Majority of species were Polychaete with Cirratulidae, Amphinomidae, Paraonidae and Capitellidae being dominant, respectively. Porifera, Nematoda, Malacostraca, Enopla, Bivalve, Osracoda, Ophiuroidea and other macrofauna comprised the remaining species, respectively. The results showed sediment type did not affect species distribution and richness. The acoustic mapping of southern coast of the Qeshm Island provided preliminary data and initial overview of the sediment biotopes and faunal communities. This was the first attempt to integrate geological, biological and dynamic data of the region.
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Page 27Science and technological developments provide new opportunities to exploit aquatic resource. Hence, it is important to understand biotic and abiotic conditions of aquatic ecosystems. Objective of this Paper is to report findings of the study of nitrate and phosphate contents of water and effects of other physicalchemical parameters in the southwest regions of the Caspian Sea in the spring and summer of 2008. It focuses on the evaluation of nitrate and phosphate concentrations and compares the variations of these parameters with those of previous surveys. Fourty eight Water samples were collected from 18 stations along 6 transects: Astara, Lisar, Anzali, Kiashahr, Chamkhaleh and Chaboksar. Water samples were collected below 10 m depths in western parts of the southern coasts of the Caspian Sea. Temperature, pH and salinity of water were measured and recorded in situ. No significant differences were detected between concentrations of nitrate, phosphate and other parameters studied in the water column at different depths and stations in the six transects. Comparison of results obtained from the present study with those of previous surveys indicated that increasing trends in concentrations of nitrate and phosphate are probably caused by discharge of untreated domestic sewage and the discharge of pesticides from agricultural activities into rivers.
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Page 35The aim of this study was to obtain a basic knowledge of the fatty acid compositions and consequently, determination of diet for Turbo coronatus by means of fatty acids biomarkers. Samples were collected during a year (April, July, October 2007 and February 2008) in coastal areas of Chabahar Bay in Oman Sea. Biomarker fatty acids revealed that diet of Turbo coronatus included phytoplankton, zooplankton, detritus, bacteria, diatoms and red and brown algae. Thirteen fatty acids were identified by using GC/MS. Saturated fatty acids were the most abundant compounds of total lipids. Monounsaturated fatty acids of 16:1n-9, 18:1n-9 and 20:1n-11, were also observed in all samples. No significant differences were observed between total contents of saturated as well as total contents unsaturated fatty acids in different seasons (P>0.05). This suggests similar sources of diet, but in different combination for the mollusc in different seasons.
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Page 43Global Maritime Distress Safety System (GMDSS) is one of the best and most efficient systems for emergency. The systems have been developed to provide mariners global communications and locating network. This system includes land stations for all INMARSAT services to reporting at sea, and so far using this communication system, in marine emergency situations has helped rescue thousands of lives. All INMARSAT information and COSPAS-SARSAT services are able to receive emergency position indicating radio beacon (EPIRB) data and coast stations. In this Paper, an approach towards improving the GMDSS systems is presented. After identifying the weak points of the current systems, following were discussed: • Analyzing and inspecting the level and amount of false signals received by the system • Identifying and inspecting the reasons behind reception of false emergency signals in the system • Analyzing the costs incurred after reception of false signals in GMDSS systems
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Page 51Atrazine is currently the most widely used herbicide in agriculture for the production of corn and other crops in the world. In the present research, the effect of acute and chronic toxicity of atrazine (herbicide) on blood biochemical indices of grass carp (Ctenopharhyngoden idella) an important species of commercial fish was studied. In acute toxicity, pollutant toxicity to fish was tested by using lethal concentrations and determining the LC50 (lethal concentrations for 50% of fishes). Obtained results from PROBIT analysis showed 96h-LC50 values at 80 mg/L of atrazine. In chronic toxicity, the fish were exposed at different concentrations of atrazine (0, 10, 100, 1000, 10,000 μg/L with three triplicates for each treatment) for a month (30 days). Sampling was carried out in three times (10th, 20th and 30th days). The results showed that plasma total protein, albumin, glucose, cholesterol and triglycerides decreased significantly (P<0.05) with increasing concentrations and days. Results also showed that minimum mortality rate of fish belonged to control (0%) and 10 μg/L and maximum mortality was belonging to 10000 μg/L up to the 10th day and 1000 μg/L up to 20th day and reached 100%. Therefore, these parameters could be used as an index for evaluation of pathological conditions of this fish species.