Identification, abundance and biomass of benthic communities in south east coasts of the Caspian Sea (Golestan Province)

The frequency and distribution of benthic species in the south east coast of Caspian Sea (proposed site for cage and pen culture) were studied. Sampling was carried out in 2 water depths (1, 5) meters and 12 stations were sampled in each depth using VanVeen sampler. Totally, 11 taxa were identified: Pyrgulidae,Ampharetidae, Neritidae, Nereidae, Cardidae, Gammaridae, Naididae, Balanidae, Foraminifera, Ostracoda and Cumaceae. The most abundant taxa were Gastropoda (66.36%), Foraminifera (15.66%), Polychaeta (14.09%) and Bivalvia (1.65%) respectively. The maximum and minimum biomass was 164.1 g/m in summer and 6.56 g/m in spring. Depth, substratum, season, season-depth interaction, season- substratum –depth interaction had significant effects on biomass and had no significant effect on abundance

Annual cycle of ovarian development and sex hormones of grey mullet (Mugil cephalus) in captivity

The grey mullet fingerling were imported to Iran in 1997 from Hong Kong and in coastal fish pond of north part of Iran were successfully cultured in order to obtain broodstocks and induce artificial reproduction. Seasonal changes in serum concentrations of Testosterone, 17-β Estradiole (E2), 17-α Hydroxy Progesterone and also the level of calcium, Triglyceride and cholesterol in females grey mullet in captivity were measured by Radioimmunoassay or colorimetry, respectively. Investigating of sex steroids in different sexual maturity indicated that increasing of oocyte diameter and sexual maturity development serum testosterone was increased significantly (P0.05). These results suggest that the seasonal changes in serum lipids and gonadal steroids were associated with reproductive development. The data also support the hypothesis that the shortening photoperiod is a major factor in stimulating reproductive activity in striped mullet

Distribution, abundance and biomass of Polychaeta in the north coast of Gorgan Bay

The biomass, distribution and ecological index of Polychaeta in the north coast of Gorgan Bay was assessed during spring to winter 2004. Sampling of benthic organisms was also conducted seasonally. Polychaeta species such as Hypniola annenicova (Ampharetidae) and Streblosplo gynobranchiata (Spionidae) belonging to sessil polychaetes and Nereis diversicolor (Nereidae) belonging to mobile Polychaeta were distinguished. The maximum and minimum biomass was 4489.77±712.13 and 4150~c246.37mg/m^ (2) in summer and winter respectively which showed a uniform distribution in all depths. Results indicated no difference in diversity and evenness index in depths and seasons during the year. The highest prevalence and richness of Polychaeta diversity were observed in summer especially in waters one meter deep

Determination of polycyclic aromatic hydrocarbons (PAHs) in water, sediment and tissues of five sturgeon species in the southern Caspian Sea coastal regions

Concentration levels of 16 polycyclic aromatic hydrocarbons (PAHs) consisting of naphthalene, acenaphthylene, acenaphthene, fluorine, phenantherene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, indeno(1,2,3-cd) pyrene and benzo(g,h,i)perylene were measured in water and sediment samples collected from the southern Caspian Sea coasts at four stations of Noshahr, Freydoonkenar, Sari and Amirabad during autumn, winter and spring of 2005-2006. Also, tissue samples from five sturgeon species including stellate sturgeon, Persian sturgeon, beluga, Russian sturgeon and ship sturgeon were obtained. Samples were analyzed by gas chromatography after the extraction process and the obtained data were statistically analyzed using One-Way ANOVA analysis at confidence level 95%. The mean concentrations of PAHs in water and sediment samples were 0.004-2.946 mgl-1 and 0.024- 2.336 µg g-1, respectively. No significant difference was found in the mean concentrations of PAHs among stations and seasons of the examined samples. Also, mean concentration of PAHs in the liver, muscles,gills, kidney and gonads of five sturgeon species was 0.81-1.34 µgg-1. The results of this study show that the levels of PAHs in water, sediment and sturgeon organs were below the acceptable levels of PAHs proposed by USEPA and WHO

Investigation on the effects of aeration on the survival rate of Acipenser persicus fingerlings on the rearing period on the earthen ponds of Shahid Marjani sturgeon farming complex

In order to investigate of aeration apparatus role on survival rate of Acipenser persicus fingerlings on the rearing period, 6 earthen ponds with 2 hectares surface and 2.5 water depth were selected. This research continued by 2treatments of aerated and unaerated ponds with 3 replicates of density 80000, 120000 &160000 induvial of larvae / hectares. Physicochemical factors such as T, Transparency, D.O, Nitrate, PO4, Alkanity, and pH were recorded weekly. Live food biomass and growth rate of fingerlings were estimated weekly, too. Obtained data were analyzed by t-test and ANOVA and Duncan test (P>0.05). According to results the survival rates of fingerlings in experimental treatments were significantly different. Physicochemical factors of water quality had no differences except the value of DO, during third weeks of rearing period

Investigation and comparison of heavy metals in sediment, water and popular fishes of Golestan Province of south Caspian Sea

Golestan coast at south of Caspian Sea is the most important aquasystems, because of its relation to lagoon, bay and fresh water rivers and of its role in life cycle of bony fishes. The study of heavy metals, as a kind of chemical and environmental pollution is an essential program; because, they accumulated in the aquatic environment and human food chain that cause ecological damages. In this study, we determine the concentration of four heavy metals (Cd, Cr, Zn, Pb) in some most consumed fishes, such as Liza auratus, Cyprinus carpio and Rutilus frisii kutum in winter, spring and summer seasons locating at 11 sites (west and east coast, Gomishan Lagoon and Gorgan Bay). The fishes which were caught from the mentioned areas after biometry, immediately freezed and transferred to laboratory for further analyses. Then, water and sediment samples were acid digested and assessed for determination of Cadmium, Lead, Zinc and Chromium levels using atomic absorption spectrometer (AAS). The results showed that the highest concentration of Lead (214.83 ppb) was related to Gomishan Lagoon and the lowest Chromium level (28.83 ppb) was observed in the water specimens sampled from east coast in winter. Otherwise, the highest concentration of Zinc (300.7 ppb) was found in sediment specimens sampled from Gomishan in summer and the lowest concentration of Cadmium (12.7 ppb) in Gorgan Bay in summer. According to the results, the concentrations of heavy metals in liver tissues excised from fishes were higher than that in muscle tissues. Also, there was significant differences were observed between Chromium concentrations in muscle tissue of Cyprinus carpio with sex but there was not for other fish. In this investigation, we found a positive liner relationship between accumulation lead with age for Rutilus frisii kutum. On the other hand, no significant relationship was found between accumulations of heavy metals with age for other fish. Comparison of the resulted mean concentrations of heavy metals with international standards (WHO, UK (MAFF), NHMRC), showed lower concentrations in liver and muscle tissues of sampled fishes

Concentration of heavy metals (Cd, Cr, Zn, and Pb) in muscle and liver tissues of common carp (Cyprinus carpio L., 1758) from coastal waters of Golestan Province

Concentrations of four heavy metals (Cd, Cr, Zn, and Pb) in the common carp (Cyprinus carpio) were assessed in winter, spring and summer seasons of the years 2008. Four coastal areas in the west and east, Gomishan Marsh and Gorgan Bay including 11 sites were sampled. After biometrical measurements of the fish, specimens of muscle (104) and liver (36) tissues were immediately frozen and transferred to laboratory for assessment of heavy metal concentration. Dry ash method and atomic absorption spectrometer (AAS) of Perkin Almer (400 model, German) were used to assess metals concentration. In the process, analysis of variance (ANOVA) and Tukey-test were implemented. Heavy metals concentration in kidney tissue was higher than muscle tissue. In carp muscle tissue, level of zinc was highest and the next categories were those of lead, cadmium and chromium, respectively. A significant difference was observed between chromium concentrations in muscle tissue of Cyprinus carpio with sex (P<0.05). The concentrations of heavy metals in liver tissues were higher than those of the muscle tissues and in all cases; they were lower than mean allowable concentrations of international standards (WHO, UK, MAFF and NHMRC)

Analysis of sturgeon fishes reproduction statistics on the northern part of Alborz region

Out put of sturgeon fish hatcheries on the Northern provinces analyzed. Unfortunately, for many reasons such as decreasing of brood fishes ,unsuitable and unprofessional managements, lack of sufficient financial supports, ageing of laboratory and incubation instruments, unemployment of energetic expertise sturgeon propagation and restocking programmes get decreasing trends. Thus managers must planning for activating of sturgeon restocking and propagation subjects

Study on rearing movine carps in the ponds of brackish water and freshwater

In this study, mono culture of Cyprinus carpio in fresh water and brackish water with 3500 specimens per hectare with 3 replication each carriedout from midel April to end the October 2010 and mide april to end the October 2011 recptively. Juline fish with 40 gr weight takeup from the sade voshmgir and after prepara tion of rearing ponds were introduced to pond according to appropriate and caluclate stocking density. Juline were fed by concentracted food(GFC). Feeding calculation based on percentage of body weight varied from 5 to 10 % of body weight. In fresh water Average weight and lenghth were in the stage time stocking 40 gr 14.68 cm and at the end of cultuivation period were 704.26 gr and 37.04 cm respectively. Inorder to comparecultivation of Cyprinus carpio in freshwater with breackish water another stocking 350 specimens per hactar with 3 replications also tookplace in this study. Junlin fish with average weight of 40gr and average length of 14.12cm were introduced to the ponds. At the end of rearing period average final weight was 700.26 with average length of 38.86cm.mean daily growth in fresh water treatment was 3.39. in brackish water replication the average daily . average condition factor in fresh water was 2.41. The average value CF in breackishwater was 1.39. in this research was survival rate in the fresh water and breackish water were more 77%