نشریه پژوهش های علوم و فنون دریایی
سال یازدهم شماره 4 (زمستان 1395)

This study evaluated and compared the accumulation of Ni in the muscle tissue of fish Cobia (Rachycentron Canadum) and its relation to total length, total weight and age of the fish in the waters of the northwest of Persian Gulf in 2014. Ninety six fish samples were collected at 6 length groups. To measure the level of essential elements, the samples were digested by wet digestion method and by Perkin Elmer 4100 AAS instrument. The means were compared using analysis of variance (ANOVA) and correlations and significant differences were estimated at 95% significance level. Mean concentration of Ni in the muscle tissue of Rachycentron Canadumwas 0.148±0.05 mg/kg dry weight (P<0.05). The highest concentration of Ni was found in the group with larger than 127 cm length (0.238±0.9 mg/kg dry weight). A positive correlation was established between the total length and total weight and age and accumulation of Ni at P. Concentrations of Ni in muscle of Rachycentron Canadum were lower than international standard of WHO (0.38 mg/kg).

In this study, fatty acid profile of Acartia tonsa in the summer and spring of 2015 in the Caspian Sea (Noshahr) was studied. Sampling was performed below the surface of the water by special zooplankton sampling net (100 microns). .Acartia tonsa samples were isolated, filtered and frozen for fatty acid examination and composition of fatty acids was investigated by GC/MS instrument. The results showed that total saturated fatty acids in spring and summer were 62% and 31,12% , unsaturated fatty acids (MUFA) were 23.89% and 26.11% and  unsaturated fatty acids (PUFA) were 14.59% and 23.51%, respectively. Statistical analysis suggested that there was no significant difference between the independent groups of fatty acids in spring and summer except for some of the important fatty acids such as Myristic acid, Palmitic acid, Oleic acid, EPA and DHA which were significantly different in two seasons. The reasons for the differences in the composition of fatty acids are probably related to seasonal changes, availability of food resources, and the composition of fatty acids in the food supply and density of phytoplankton species in each season.

This study was carried out to determine the heavy metal content ( Pb and Cd) in muscle and liver tissues of Pomadasys kakaan   in Bandar Abbas during winter 2011 and summer 2012. After biometry of the fish, muscle and liver tissues were separated. The amount of Pb and Cd were measured by atomic absorption spectroscopy (Varian model GTA 100). Based on the results, the average concentration of Pb and Cd in liver tissues were observed to be 0.1334±0.0234 and 0.0255±0.0077 µg/g respectively and in muscle tissues 0.0439±0.0106 and 0.0041±0.0007 µg/g, respectively. The difference between the average concentration of Pb and Cd in liver and muscle tissues is significant (P<0.05). Average accumulation of Pb and Cd in liver and muscle tissues were not difference significantly between two seasons (P>0/05). The comparison of the results with permissible limits of WHO and EPA showed that the concentrations of these metals are low.

In order to evaluate copper nitrate (Cu (NO3)2) effects on some blood biochemical indices in Acipenser nudiventris, 120 fish were exposed to 0, 1, 5 and 10 mg/L of Cu (NO3)2  in 12 aquariums with  a volume 100 liters. Blood samples were collected from fish at 24, 48, 72 and 96 hours. The highest percentage of mortality of up to 24 hours after exposure to the toxin was related to concentrations of 10 (70 percent) and 5 (50%) and 1 (10%) mg/l, respectively. After 24 hours, fish died at 5 and 10 mg/l of copper. However, at concentration of 1 mg/L up to 96 hours almost 20 percent of fish were resistant. No mortality was observed in the control group. Triglyceride levels at concentrations of 10 mg/l Cu (NO3)2, was 479 ± 7.7 mg/dl after 24 h and decreased significantly in comparison with the control (709.3 ± 69.3 mg/dl) and at 1 mg/l concentration of Cu (NO3)2 in 48, 48, 72 and 96 hours it reached 237.9 ± 4.2, 23.5 ± 0.8 and 226 ± 0.6 mg/d, respectively (P < 0.05). Cholesterol level at concentrations of 5 and 10 mg/l Cu(NO3)2, was 206.6 ± 7.7 and 229.3 ± 0.6 mg/dl, respectively, after 24 hrs, which had increased significantly compared to the control and 1 mg/l Cu(NO3) concentration (P < 0.05). Glucose levels, at 1 mg/l concentration of Cu (NO3)2 , were 81.5 ± 1.4, 73 ± 1 and 69.3 ± 0.6 mg/dl in 48, 72 and 96 hours, respectively, that had increased significantly compared to the control (38.9 ± 1.3 mg/dl) (P < 0.05). Total protein levels were 2 ± 0.1, 1.9 ± 0.1 and 1.9 ± 0.1 mg/dl, at 1 mg/l concentration of Cu (NO3)2,in 48, 72 and 96 hours, which had decreased significantly compared to the control (2.1 ± 0.1 mg/dl). Based on the obtained results, copper nitrate affected biochemical indices in blood of ship sturgeon and showed severe toxicity at higher concentrations.

Caspian Sea isa unique laboratory, for studying all aspects of oceanography and coastal geology. The main aim of this study was to investigate: textural andmineralogicalcharacteristics ofcoastlinedeposits in the south Caspian Sea. Initially, 100 sediment sampleswere taken in summer2014, along 700 km of the southern Caspian Sea coasts (from HosseinGholi Bay to Astara, one sample per 5-8 km).In addition, after sampling, coastal geomorphology and structures were evaluated and manypictures were taken. Optical mineralogy and grain size analysis were performed on sediments. Heavy mineralsincluding ilmenite, magnetite and goethite, pyroxene, apatite, zircon and garnet and also light minerals included quartz, plagioclase, orthoclase, carbonate fragments and bivalveswere identified. Mapping the distribution of minerals showed that eastern coastline sediments are rich in light minerals and carbonate fragments derived mainly from the erosion of Kopeh-Dagh Mountains. The central and western coast is dominated by heavy minerals, primarily ilmenite and magnetite that are supplied by the Sefidrud River. The moderate abundance of light minerals in the central region results from the sediment flux of the rivers that drain the Cenozoic and Quaternary volcanic coverage and Mesozoic sedimentary deposits.A closer look and compliance with regional geological maps, mineral distribution and beach slope,it was found that in the regions of the study area that the sea slope in the shallow parts are steep and slope of the beach is gentle (east Mazandaran and central parts of gilan province) distribution of heavy minerals such as magnetite and goethite is higher than other areas, while the distribution of Gabbro-Dioritic, and carbonate fragments are more in steep beachareas andareas of sea bed with gentle slope (West of Gilan and Mazandaran). Also gravely coasts are formed in the steep sea bed and beach areas, as the small particles and light mineralsare washed away in these areas.

The aim of this study was to investigate the physical and chemical parameters and determine detergent levels in Taar River (from Taar Lake to Mamlou dam region). In this study, physical and chemical parameters of the river, including pH, DO, EC, COD, BOD, Cl- l levelsand also detergent levels were determined. For this purpose, 5 stations were designated alongside the river. The results showed that the pH levels were between 8.89 -10.12, EC was measured between 380-800 µs/s, DO levels were between 2.14 – 2.8 mg/l, levels of Cl- were between 1.2 - 47 mg/l, BOD measurements showed levels between 0-16 mg/l, COD levels were between 2-36 mg/l and detergent concentrations were less than 0.02 mg/l in all stations. Comparing the results with Department of Environment standards for surface waters, at the time of sampling, the chemical and physical parameters measured and detergent levels of Taar river were in the recommended standard range.

In recent years, use of herbs as dietary growth stimulant factor and replacing it with artificial materials in aquaculture is widely discussed. The impact of black cumin seed (Nigella sativa)powder at four levels of 0, 0.5, 1 and 2 percent, per kilogram of diet, on growth, survival and resistance to salinity stress in the Caspian roach (Rutilus rutilus caspicus) was investigated for 60 days. At the end of the study, growth factor and feed conversion factorwere calculated. In addition,the effect of black cumin seed powder on resistance to salinity stress was investigated, in intervals of 24, 48 and 72 hours.The results showed that using black cumin seed, up to the 0.‌5 percent, cause highest body weight gain (7.09±0.38), specific growth rate (1.59±0.04), condition factor (0.11±0.006) and lowest feed conversion factor (1.29±0.08) in fingerlingroach. Statistical analysis showed significant differences (p< 0.05) in growth indices and feed conversion factor, between treatments and the control group. This study showed that black cumin seed powder in the diet, despite increased growth performance in roach, lacked positive effect on the resistance to salinity stress in the fish.

The increased industrial applications of nanoparticles increase the possibility their deposition into aquatic ecosystems and thereby threatening the aquatic life. Therefore, this study aimed to provide the toxicological effects of ZnO NPs (0, 1,2,4,8 mg.L-1) on certain hematological indices of Koi fish for a period of  2 and 10 days, under static bioassay. A significant decrease in hemoglobin (Hb) content 7.3±0.19, red blood cell (RBC) count 1.41±0.03, hematocrit (Hct) value 22±0.66, mean cellular volume (MCV) 155.35±5.29 and mean cellular hemoglobin (MCH) 51.2±2.07 (except on 4 mg.L-1dose) was noticed throughout the study period of 10 days when compared to control groups. In contrast, mean cellular hemoglobin concentration (MCHC) levels 4±0.23 were found to increase during the study period.Our results demonstrate that high ZnO NPs concentrations in the aquatic environment may have adverse effects and cause acute changes on hematological parameters of Koi fish.