Study of hydrology of the Gorgan Bay

At the end of 2011 Iranian Fisheries Research Organization- Inland Waters Aquatics Stocks Research Centre measured salinity, temperature and density of the Gorgan bay. I have used these data and produced the profile of them versus to the depth and estimate the depth of mixed layer versus to the distance from the beach and bottom. This work has been carried out almost at 5 selected lines which are indicated on map. These profiles show that as the distance increase from the beach the mixed layer depth decreases. We also know that the maximum mixed layer depth is in center of bay. The increase of temperature decreases the mixed layer and vice versa. Input flux of mechanical energy of the wind also increases. This depth provided the wind stronger enough. This can lead to increase of turbulence kinetic energy, which with subcritical values of Richardson number; can significantly increase mixing in upper layer (mixed layer) of the bay. How ever, the excessive evaporation increases the water flux into the bay. This can account for the increase of the mixed layer depth in time. The estimated mixed layer depth has a modulated distribution over the area studied. This show that, mixing processes in the upper layer may have different sources

Study on ecological capacity of the release sites of the fingerlings of sturgeon and bony fishes in order to regulate the restocking program at the Gorganrud River

This review is started from April 2002 in Gorgan River and continued for one year. Three sampling stations along the river to the mouth of the estuary were 4000 meters away from the bridge to the village Charqly all samples were collected in this area. Four million sturgeon larvae with average weight of 3/2 grams were obtained from martyr Marjani and Vushmgir Dam farms. Over 40 days released at release stations, and 316 million bony fish fingerlings are being release that 282 million were whitefish, 25 million carp and 9 million bream from Vushmgir Dam and Syjval Bream Center within two months at the release stations in Gorgan River. At sampling stations, especially estuaries to determine the shelf life of fry in the river and to determining migration into the river as well as physical - chemical and assess the frequency and biomass of feeding materials (phytoplankton, zooplankton, and benthos) at the sampling stations in Gorgan River were studied. The entire estuary to the sea makes itself. Maximum migration happened at sunset. Average Debbi for 20-year was at the rate of 14.95 cubic meters per second. In 2002, the annual average was 20.8 cubic meters per second, respectively. Evaluation of abundance and biomass of feeding materials (phytoplankton, zooplankton, and benthos) indicates the status of the average biomass of phytoplankton in the river at the release station was 23/75 mg per liter that was highest in September and was lowest in December. Mean primary production based on a 145 mg chlorophyll cubic meters. 6 orders of benthic invertebrates were observed. Benthic including 9 families and 11 genera have been identified including groups of insects, worms, low-tar and Polychaetes, crustaceans, bivalve and gastropod. But at the release station (S2) the highest levels of benthic biomass (18/18 grams per square meter) degree of diversity of benthic organisms (12) species have largely been seen as a maximum in April and minimum in December. Also zooplankton condition, zooplankton total of 27 genera belonging to five categories, Rotatoria, Kladvsra, Coupe Pvda, Balanvs, and protozoa were identified. In general, in September zooplankton has the greatest diversity and abundance and in September and March, the lowest number is observed