3 research outputs found

    A survey on environmental effects of shrimp pond culture effluents in Gwatar area (Sistan & Blouchestan)

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    Present project was conducted in shrimp farm located in east of Chabahar in Sistan and Balouchestan province.Twentieth sampling stations at three locations (i.e. 2 stations in supply channel,13 stations in drainage channel and 5 stations in Gwatar Gulf) were selected to determine physical and chemical factors such as; temperature, salinity, dissolved oxygen, pH, nitrate, nitrite, ammonia, phosphate and biological parameters for example Chlorophyll a, phytoplankton and zooplankton. Sampling was conducted once a month from March 2003 until January 2004. The results revealed different bioenvironmental area in the three locations (i.e. supply channel, drainage channel and Gwatar Gulf) over the study period. Concentration of salinity ,pH , nitatr ,nitrite ,ammonia and chlorophyll a in drainage channel were more than supply channel and Gawtar Gulf. While concentation dissolved oxygen and phosphate were in drainage channel less than Gawtar Gulf.Also, sediment with small grain size (clay and silt) caused uptake phosphate and amount phosphate decreased in drainage channel. Considering with lack of environment standards in Iran shrimp effluent, data compared with others countries standard. Results showed that with considerable farm area, value of temperature, salinity, dissolved oxygen and pH were in permit range in Gwatar Gulf while concentation nitrate, phosphate and chlorophyll a were sometimes more than permit range that could cause plankton bloom. Also, Gwatar Gulf were influence monsoon. Nitate, phosphate, chlorophyll a and phytoplankton increased in gwatar Gulf.Regards with that postmonsoon was simultaneus with shrimp harvest.Therefore, increase some parameters could be caused from shrimp effluent or postmonsoon. Thirty four phytoplankton genus were identified including diatoma, dinoflagellate, cyanophyta and chlorophyta. In each area maxiumum percentage of phytoplankton were belonged to diatoma (63%) in supply channel, cyanophyta (51.7%) in drainage channel and dinoflagellate (94.5%) in Gwatar Gulf.Amount and range chemical and physical factors and plankton composition were different in drainage channel, supply channel and Gwatar Gulf. Cyanophyta could grow more in drainage channel.Percentage of aboundance and diversity of phytoplankton changed in 2002 inrelation to years ago( before shrimp culture, 2000 year and 2001 year) specially in Gwatar Gulf. Mainly percentage of zooplankton were copepoda and thintinida respectively.Diversity zooplankton decreased ratio to years ago. In drainage channel, abundance total of phytoplankton and zooplankton were more than Gwatar Gulf and supply channel

    The assessment quality of effluent from shrimp aquaculture site in Gwater

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    Present study was conducted in shrimp farm located in east of Chabahar in Sistan and Balouchestan province from August 2001 until May 2003. Fourteen stations at three locations (i.e. supply channel, drainage channel and Gwatr Gulf) were selected to determine physical and chemical factors such as; temperature, salinity, dissolved oxygen, pH, nitrate, nitrite, ammonia, phosphate, silicate, total suspended solid and turbidity. Sampling was conducted twice a month during the shrimp culturing period and monthly at other times. Water samples were collected every two weeks to determine Chemical and Physical factors, Chlorophyll a, Phytoplankton and Zooplankton. Sediment samples were collected seasonally to examine Macrobenthos, Grain size and Total Organic Matter. The results revealed different bioenvironmental area in the three locations (i.e. supply channel, drainage channel and Gwatr gulf) over the study period. One-way analyze of variance of chemical and physical factors indicated significant difference between different times as well as different stations (p<0.05). The negative relationship was observed between the culturing production area and the amount of average dissolved oxygen, pH and total suspend solid. An increase in the culturing production area in 2002 as compared to that of 2001 causes a decrease in the amount of these factors. However, it dose indicates positive relationship with nitrate, nitrite, ammonia, transparency and chlorophyll. Forty nine phytoplankton genus were identified, which mainly belong to diatoma, dinoflagellate and green blue algae. Diatom was dominated among these groups. Diatom and green-blue algae and diatom comprised %79, %69 and %64 of phytoplankton flora respectively in supply channel, Gwater Gulf and drainage channel. Copepod and thintinnida were the major groups of zooplankton. High abundance of bivalve, Polychaetes and amphipoda were found in supply channel, Gwatr Gulf and drainage channel respectively. Analysis of grain size showed the existence of sandy sediment in Gulf of Gwatr and sandy-loom in supply channel. Drainage channel sediment found to be sandy-loom, sandy-silty-loom and sand loom. Among three locations, the highest TOM was found in drainage channel. In last location, production area in 2002 increased as compared to that of 2001, which showed negative relationship with salinity, nitrate, nitrite, ammonia and chlorophyll a. Drainage of the Gwatr s shrimp farm did not cause any thermal contamination in the location. Shrimp aquaculture activities caused an increase in the average of salinity, range of pH in the Gwatr Gulf

    Identification of local microalgae & their evaluation as live food in aquaculture from Oman Sea

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    Microalgae are very important organisms in aquaculture as major live food in all growth stages of bivalve, some larval stages of crustaceans, some fishes and zooplankton. In this project with the knowledge that local algae can provide better nutritional balance for local animals. Microalgae were isolated, identified and evaluated for their nutritional value for the first time. Another aim of this research was to create phytoplankton culture collection (Bank) in the south of Iran. Water was sampled from Sistan and Baluchesta coasts, then isolation and purification process were carried out in the lab. Species identification was based on morphology and molecular analyses. rDNA was extracted from each strain after PCR, partial LSU-rDNA region were sequenced and compared with similar sequence from GenBank. In order to evaluate their nutritional properties, relative growth, fatty acids composition, total lipid, carbohydrate, protein, and some vitamins of each purified strain were determined. Totally 25 species were isolated and purified, of which 12 strains were recorded in GenBank and their nutritional potential were assessed. Dunaliella cf. bardawill, Isochrysis sp. Cheatoceros sp. Clorella cf. volgaris, Ochromonas sp. and Synechococcus sp. were the most important species research. Iranian strains were varied in their amount of protein (27-40%), carbohydrate (221%) and lipid (8-13%). Proportions of SFA (21-48%), MUFA (33-53%) and PUFA (11-28.5%) were varied among strains. The highest amount of PUFA and B3 vitamin were found in Clorella cf. vulgaris. The highest content of protein (40.12% dry wt) and total fatty acid concentration (30% dry wt) were found in Dunaliella cf. bardawil and Ochromonas strain(CHPO2) respectively. The maximum content of total fatty acid was observed in Ochromonas sp. (CHPO2). Cheatoceros sp. had higher relative growth rate in comparison with other species
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