Investigation on meiofauna and substrate characteristic in the southern Caspian Sea (Guilan Province)

Meiofauna with a size of 100-1000µ having important rule in food webs. This study was carried out in autumn and winter 1992 along 30 transects at depths of 10, 20, 50 and 100m. The sediment samples were collected by grab (0.1 m2 area). In addition to identification of meiofauna, the sediments were examined to determine T.O.M. and grain size parameters. The results showed that bivalvia, foraminifera, nematoda, ostracoda and copepoda were dominant taxa among 12 identified fauna groups, in which foraminifera and bivalvia were the most abundant. The nonparametric Kroscall-walis test showed significant difference among abundance of meiofauna in different depths. The depth of 20m had the most abundance and with increasing depth (5O and 100m), the abundance had a descending trend. The maximum and minimum mean abundance of meiofauna varied from 29315±37248 and 825±498 ind/10 em2 for depth of 10 and 100m, respectively. The substrate characteristics indicated that the depth of 50 and 10m included the most and the least organic matter. Also all depths indicated the same grain size and sediment composition was mostly silt. Most of meiofauna were found in substrates with 4 to 8 % organic matter

Bio-ecological study of river estuaries in Guilan province

The Caspian Sea with brackish water is known as typical environment due to geo position, precious biota and the largest land-enclosed drainage area in the world. Macrobenthos were performed the main group of the Caspian Sea fauna. While they use as environmental bio-assessment, they have not completely studied in the Caspian Sea especially in estuaries environments. In this survey were studied eighteen river estuaries in Guilan province off Caspian sea southwest including Asrara, Chelevand, Lemir, Havigh, Shirabad, Khotbesara, Lisar, Karganroud, Navroud, Nokandekeh, Sefidrud, Heshmatrud, Langerud, Polerud and Chabokrud. The macro-invertebrate sampling was conducted seasonally at eight stations during autumn 2008 to autumn 2009. The macrobenthos organisms were identified as possible level in genus or species. The Shannon Wiener diversity and the Hilsenhoff biotic indices were used for evaluation of environmental quality. In this study, 69 genus identified that belong to 36 families and 16 orders. The most presentation of genus belongs to Chironomidae family with twenty six genus while others families were included forty three genus. The most average of macro-invertebrate abundance belong to order of Diptera with 35 %, subsequently the abundance of Amphipoda and Bivalvia orders occupied the second rank with 8.2 %. Orders Polychaeta, Oligochaeta and Cumacea had a low abundance during the study, however the Polychaeta showed a high abundance in some seasons and stations (up to 25%). The Plecoptera was rarely observed in some stations with high abundance. The Stenogammarus genus had the normally distribution during study, while Chironomidae genera as Eukifferiella and Cricotopus were measured in the high abundance during autumn 2008 to spring 2009. While Streblospio and Limnodrilus had the high presentation during winter and spring 2009, Cerastoderma sp. showed a high percentage in spring and summer 2009. The result of Shannon Wiener index values showed a significantly difference among regions for most seasons. There was also observed significantly difference for diversity values among stations in different seasons. According to Hilsenhoff biotic index for water quality classification; the most stations had good quality in spring 2009, while they were slightly and moderately good condition in winter 2009. The water quality of the Caspian Sea stations was in good condition as compared with the rivers estuary stations

Study of Shovier and Mirzakhanlo dam reservoirs in Zanjan province in order to aquaculture activity

Inland water aquaculture activity have been known as an important approach for protein production while reservoir lakes recognized to have a significant potential for this purpose. Zanjan province in Iran with several dam reservoirs is suitable for aquaculture development. This study was conducted on biotic and abiotic factors of two lakes Shovir and Mirzakhanlo in order to determine aquaculture potentially of reservoirs. This two lakes located on different climatic region; Shovir located in region of semi arid area with very cold weather in winter, while Mirzakhanlo is in semi humid area and warm weather characteristic. In this study the plankton, benthos and fishes were assessed and the 15 hydrochemical factors were measured in order to determine the fisheries potential for fish introduction or release. The results showed that the phytoplankton abundance of Mirzakhanlo varied between 1.6 to 45.2 million cell/l. with 32 identified genus. The zooplankton abundance varied between 48 to 632 n/l. and 22 identified genus. The abundance plankton in shovir varied between 1.350 to 34.2 million cell/l. and 240 to 4500 n/l. for phyto and zooplankton respectively. Macrobenthos biomass were 21.4 and 0.34 g/m^2 in Shovir and Mirzakhanlo lakes respectively while Chironomidae and Tubificidae families were dominant groups. The lake sediment organic matter were 4.3 and 3.2 % respectively. In ichtiology survey identified 5 and 7 species in Mirzakhanlo and Shovir lakes respectively. The hydro-chemical results indicated no restriction for aquaculture activity and according to trophic model both lakes are recognized as meso-eutrophic and eutrophic. Despite of climatic restrictions, the potential for fish production was estimated about 321 and 151 kg/ha for Shovir and Mirzakhanlo lakes respectively that can be improved by using agricultural and the other native facilities

The study of some limnological study of the Kan river in the catchment area of the Persian Gulf Martyrs Lake (Chitgar), Tehran trophic index in Anzali lagoon

This study focused on identification phytoplankton, zooplankton, benthos, fishes and relationship between biotic and abiotic parameters at three stations in the Kan river during 2014. This study identified 19 phytoplankton taxa. The findings showed, the diatoms abundance were dominated in the river. The chlorophytes abundance were recorded the lowest abundance in this study. The nutrients and water temperature were the significant abiotic parameters to increase cyanophytes and chlorophytes abundance in the Kan river. This study identified 26 zooplankton taxa. The Rotatoria and Protozoa abundance were dominated in the Kan river. Based on CCA, there was no correlation between abundance zooplankton and abiotic parameters. The biodiversity index of plankton was between 1.8 and 2 and the lake situation is located in the mesotrophic category. The study of the Kan river fishes showed, only one endemic fish species Capoeta bohsei. The length (between 38 and 270 mm, average 144±86 mm) and weight (between 1.1 and 356 g, average 108.8±146.7 g) of the C. bohsei were varied during the study period. The 19 benthos taxa were identified. The Ephemeroptera was most abundant in the benthos groups. The classification of river based on biology indicator and environmental parameters confimed that water quality is located in the moderate category

Study of Todebin dam reservoir in Zanjan province in order to aquaculture possibility

The Todebin dam reservoir has been constructed in central part of Abhar in the Zanjan province which has been studied with aquaculture purpose. This study was conducted on biotic and abiotic factors. The plankton, benthos and fishes were identified and the parasitology and bacteriology studies were performed on the lake fishes. Then the fisheries potential of the lake was calculated in respect of final fish farming amount and the fish releasing. The results showed the Bacillariophyta was dominated ِduring the study. the highest abundance of phytoplankton was between 2.1 and 12.5 million cells.l^-1 in the upper layer of lake as compared with the lower layer. The genus Cyclotella and Dinobryon belong to phytoplankton and Keratella and Polyathera belong to zooplankton were dominanted abundance. The mean biomass of benthos was varied from 5.5 to 29.5 g.m -2 and the Chironomidae had the most abundance. The ichtiology survey showed the presence of four cultured species and the Goldfish. The hydro-chemical results indicated no restriction for aquaculture activity. The oxygen average was more than 8 mg/l. The average of phosphate, nitrogen and hardness were measured 0.09±0.04, 2±0.8 and 237±94.5 mg/l., respectively. For the most hydrochemical factores, the values were significantly different between upper and bottom layers of the lake. The oxygen production and Chl-a amount were measured about 0.73 mg/l. and 7/03 µg/l., respectively. According to climatic restrictions, the cold fish culture is preferred than to culture of warm fishes. While the natural capacity of the lake was about 5 tones to warm fish culture, the fish production of trout was estimated about 40 tones. This volume will be available during four months periods and twice a year

Study of Golabar dam reservoir in Zanjan province (Zanjan Province)

The limnological study of the Golabar dam showed that in the Glabar dam inspite of bing its early establishment due to high nutrient and organic matter is located in eutrophic stage. the pH as well as bicarbonate levels shows that buffering capacity of the lake is high and the value of inorganic and organic matter measured are not considered as limiting factor for warme and cold water aquaculture. In the plankton survey 44 species of phytoplankton and 25 species of zooplankton were identified. Cyclotella , Nitzschia, Synedra and Trachelomona from phytoplankton and Polyarthera , Keratella , Filinia , Pompholyx from zooplankton were the dominant spicies.the Bacillariophyta from phytoplankton with 76.5 percent and Rotatoria zooplankton to with 76.2 percent considered the highest abundant . The average frequency of phytoplankton and zooplankton were 5*106 and 723 individual per litter. The Shironomide and Tobificide were the only two bentic group were identified in reservoir wehre their mean frequced were 293.75 and 224.30 respectively. The average biomass of bentic organism were 1.44±0.97 gr/m2.In the survey 12 species of fishes were identified. The potential natural production have been estimated to be 2.8 to 15.5 kg for bentivorous fish and varied from 53 to 175 kg /hec for plankton consumer fishes .The low temperature in several months as well as ice covered of the lake surface in particular in the months of duty and Bahman are the limiting factor of either warm or cold water fish production

Caspian brown trout (Salmo trutta caspius) broodstock supply in south western of the Caspian Sea (Guilan province)

Caspian trout (Salmo trutta caspius ) is one of the migratory fish species which lives and feeds in the Caspian Sea .This species distributed in south and western of the Caspian Sea . In order to rehabilitation of the Caspian trout in western area, the operation of the project started from the beginning of the fishing season of the 20112012. Specimens of the Caspian trout obtained from beach seine cooperatives and have been transferred to the fish farm in Asalem region .Totally, 44 specimens of the Caspian trout has been caught in two month period .Most of the fishes was from Kargan roud river . The mean length and weight of the brood fishes were 67.7 cm and 3122.7 g respectively .As at present Shilat uses just the broods of the Tonekaboon region for restocking of this species ,we recommend to use the broods of the western region separately for rehabilitation of the stocks of this region

Biological survey of Caspian kutum (Rutilus kutum) released fingerlings in Sefidroud River (Guilan Province)

Kutum fish (Rutilus kutum) is an anadromous cyprinid species that spawns in adjusted rivers to the Caspian Sea. Many million fingerlings were artificially produced and annually released in these rivers specifically in Sefidrud River by Iranian Fisheries Organization. In this study were estimated the staying period of Kutum fingerlings in Sefidrud River and its diet and growth. A small piece of the caudal fin was cut as a tagging method. About 50000 and 5200 individuals were marked during July and September 2013, respectively. The marked fish had an average total length 53.2±5.6 mm and body weight 1.11±0.26 g and were released in river around two kilometers of the estuary. The sampling of fishes had been earlier started from Feb. 2012 and continued until Feb. 2013 at five stations. Four stations were along river from three Kilometer of estuary to estuary and one station was in right side of estuary in the sea coast. The results showed that marked samples after releasing time were distributed in all studied area from 3 kilometers of estuary to estuary but they migrate mainly toward Caspian Sea in a short time. However the marked samples were observed in estuary and the sea coast after 6 and 24 hours of their releasing time, respectively, Kutum fingerlings remained in Sefidrud river ecosystem in a longer time, at least until end of our sampling period i.e. 105 days. The coefficient of vacuity index of the natural feeding study was 0.0, 49.0 and 30.6 % for phytoplankton, zooplankton and benthos, respectively. The average of GastroSomatic index, intensity of fullness and condition factor were calculated 6.30±3.25, 174.6±153.2 and 0.92±0.09, respectively. A temporal and spatial variation on main food items were observed in gut content of fish fingerlings from different locations and seasons. Gut contents were generally included 59 genera of phytoplankton, 15 groups of zooplankton and 10 groups of benthos. Nitzschia, Navicula and Synedra were dominated among phytoplankton genera with 45.83, 18.02 and 15.99 %, respectively. Among zooplankton groups; the Rotaria, Moeina and Difflugia were dominated with 22.30, 20.86 and 15.83%, respectively. Chironomidae and Gammaridae were the main food items among fed benthic animals with 83.67 and 11.15%, respectively. Furthermore 48 phytoplankton genera, 32 zooplankton genera and 6 benthic families were identified in ecosystem of Sefidrud river. Bacillariophyta phylum (with 23 genus), Rotatoria (with17 genus) and Chironomidae family were dominated in each mentioned groups, respectively. It is concluded that the Kutum fingerlings stay in Sefidrud River for a long time, although most of them migrate to Caspian Sea during first month after releasing. However dietary indices were normal in studied samples, the condition factor index seems to be low