ALBERT

Beschreibung: Persian Gulf waters (areas of Hormuzgan province) in order to determine the best location for installation of Artificial reefs were studied seasonally from December 2006 to March 2007. Distribution of funa and flora and estimation of deposit depth by SCUBA diving method, density and frequency of macrobenthose communities, frequency of ichthyoplankton communities, determination of organic carbon (OC) and Grain size and measurement of water physical factors including salinity, saturation oxygen, dissolved oxygen, temperature, chlorophyll a, in transect and subtransect was studied for recognizing the best placement to installation of artificial reefs. All areas of Shipping, military areas, around of Islands, natural habitats and entrance to jetty were introduced for excluding areas. South of Qeshm Island (transects of Bahman jetty, Bandar Masen and Bandar Salakh) are catching area for small pelagic (sardine and anchovy fishes), therefore in these areas installation of artificial reefs have confined with this restriction. Also entrance to Bahman jetty, sea plant habitats (sea grass and algae) in transects of Bahman jetty and Bandar Masen were considered as restricted areas. In this area, suitable areas for installation of artificial reefs was determined based on distribution of Ichthyoplankton societies for every transect, for macrobenthose enrichment Bahman jetty transect was calculated middle, but transects of Bandar Masen, Hengam island and Bandar Salakh was done good indicator. The deposition depth in transects of Bandar Masen and Hengam island was determined as good factor but this index was known as average factor for transects of Bahman jetty and Bandar Masen. Also, two another indicators, primary production and bottom sturdiness, were calculated as middle factor for Bahman jetty transect, but these indicators were known as good factors for other transects in this area (Bandar Masen, Hengam island and Bandar Salakh). The results of these indicators in transects of Bandar Kong and Bandar Bostaneh in Bandar Lengeh area was indicated that T. O. C and bottom sturdiness indices had no significant difference (p〉0. 05) and the whole of these transects had average priority. Bottom sturdiness, primary productions and macrobenthose communities indices had difference in Bandar Lengeh area (p〈0. 05) and these indices had average priority in Bandar Kong transect and had good priority in transects of Bandar Bostaneh and Bandar Hasineh. Ichthyoplankton community had average priority for Bandar Bostaneh transect, and had good priority for transects of Bandar Kong and Bandar Hasineh. The good priority has obtained for transects of Bandar Charak, Bandar Gorzeh and Bandar Chiroeyah. Also Macrobenthose community, primary production, water physical factors and bottom sturdiness were known as good, good, average and weakness priority respectively for transects of Bandar Charak, Bandar Gorzeh, but primary production, bottom sturdiness, water physical factors and macrobenthose community were resulted as average, good, good and average priority respectively for Bandar Chiroeyah transect . T. O. C index was determined as average priority for transects of Bandar Gorzeh and Bandar Chiroeyah and good priority for Bandar Charak transect. Finally, excluded areas maps, suitability areas maps and feasibility areas maps were drawn by Arc GIS software. In this survey, layers between 10 to 20 meters depth were recognized as the best position for installation of artificial reefs.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: Study of survey health management and diseases in hatcheries and fish farms can help us to knowledge and application control methods such as: prevention, treatment and increase high levels of production in hatchery and farms, finally. This survey carried out from 2005 to 2008 for 4 years in sturgeon hatcheries and farms of Golestan province. Sturgeon fishes include Huso Huso, Ship sturgeon, Acipenser persicus collected and for virology, bacteriology, fungius and hematology examined. Also, physicochemical parameters measured and recorded in different stages of culture. Results of this study showed that all of samples in virology was negative and did not observe any doubetful causes. In bacteriology CFU was variation from 3/9 ×105 to 6/9×10. The most parasites that detected in this survey was Cocolanus espherolanus , Sceria binopsulus semiarmatus and Amphilina fuliacea that separates from Acipenser Percicus, especially. The results about hematology parameters some important hematological indices of ship sturgeon include: The total RBC for female and mail specimens measured as 5.3±1.5 ×105, 4.8±0.5 ×105 per mm 3 respectively. The amount of haematocrit and hemoglobin for female and mail determined: 34.3±2.8, 35±1.4 percent and 10.3±0.9, 8.9±0.8 gr/dl .The MCV: 216.3± 96.2, 736.5± 102.5, MCH: 720.2±309.5, 186±0.7 and MCHC: 30±0.8, 25.5±3.4 percent respectively.The total WBC were (female, male): 21320±1054, 20580±777 per mm 3 and neutrophil: 16.4±2.5, 17±1.4 percent and lymphocyte: 74.4±2.4, 73.5± 0.7 percent and eosinophil: 6±1.4, 6.4±0.5 percent, monocyte: 2.8±0.8, 3.5±0.7 percent. There was not any significant differences (p〉0.05) between mentioned parameters in male and female (students t-test). Also evaluation of hematological parameters in bluga ( Huso huso) include: total RBC were (male , female) 5±0.3 ×105 , 4.9±0.6 ×105 per mm 3 ,respectively and hematocrit: 33.2±6.7 , 35.4±3.4 percent and hemoglobin: 11.2±1.5 , 12.2±1gr/dl and MCV: 669.9±172.2, 723.9±982.4 and MCH: 226.2±42.5, 249.5±35.4 and MCHC: 34.1±2.4, 34.6±3.6 percent respectively. The totals WBC were (male, female): 24800±707.1, 23042±1375.4 per mm 3 and neutrophil: 18.5±0.7, 21.4±1.1 percent and lymphocyte: 73.5±1.4, 68.4±1.1 percent and eosinophil: 5±2.8, 7±1.2 percent and monocyte: 3.5±3.5, 3.2±0.8 percent. According to statistically study the count of lymphocyte had significant difference between male and female fish and this count in male was higher than female. (p≥0.05).

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: The survey effect of salinity, turbidity and dissolved oxygen performed on Rutilus frisii Kutum juveniles with aim, which was determined about survival rate and histological changes in gill and kidney tissues. Juveniles provided from the Rajai's fish propagation center and then examined in Caspian Sea Ecology Research Center laboratory. The juveniles were investigated on three weight group (200-〈400, 400-〈600, 600-〈1000 mg) and two dissolved oxygen levels (7.6 ± 0.19, 3.8 ± 0.15 mg/L)in fresh water and Caspian sea water(12.5 ppt). Also, six turbidity levels (50 FTU, 430FTU, 2600 FTU, 7800 FTU, 15600 FTU) were probed in freshwater during 168hr. Each treatment has three replications. The factorial test evaluated for survival rate in treatments. The results shown that there was a significant difference among treatments in the different levels of factors, (p〈0.05, Duncan test). The juveniles' survival rate has decreased than control treatment in brackish water and turbidity in freshwater. It was demonstrated that with increasing fish weight, therefore, the survival rate is increased. The lowest survival rates under salinity stress (〉75%) had shown in 400-〈600mg weight group with dissolve oxygen: 3.8±0.15SE mg/l. In addition, the lowest survival rates under turbidity stress (95.83%) had shown that in weight group less than 400 mg with turbidity 15600 FTU. Therefore, survival of juveniles was high. However, gill tissue of juveniles under turbidity and salinity stress became short (necrosis) and thick (edema and hyperplasia) in the end of experiments. The juveniles gill tissues were not changes in the river clear freshwater. Therefore, the factors of gill tissue deformation were salinity and suspended particles in the water. However, the structures of kidney in the different groups of juveniles were similar. Nevertheless, juveniles glomerular diameter increased with increasing weight (p〈0.05, Duncan test). Furthermore, there was a increasing the internal cavity of the proximal and distal tubules and decreasing of glomeruli in diameter in the transfer of juveniles from freshwater to brackish water. Although the survival rate of juveniles is acceptable in this study, but there was abnormal changes in the structure of them gills. It appears that this change will cause a disruption in trend of juvenile's growth.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: The national research plan with title of "Study on health status of Iran Coldwater hatchery and rearing farms" was done in order to identification and tracking of main causative agents of recent mortality in Iran Coldwater hatchery and rearing farms and recognize of infected zones and design of landscape distribution of Epizootic Coldwater fish diseases in the country. This plan was conducted parallel and in same time in some polar provinces of Coldwater fish production such as Mazandaran, Gilan, Ardebil, West Azerbaijan, East Azerbaijan and Kurdistan in three years from 2006-2008. In this regard, about 23,21 and 20 farms in Mazandaran province, 30 farms in West and East Azerbaijan and Kurdistan provinces and 19 farms in Gilan and Ardebil were selected as randomly and tracking were done yearly from 2006-2008. This research was conducted according to regular planning consists of farms visit that was done according to statistical plan and completion of Questionnaires and sampling. The findings in Mazandaran province revealed that fish infections background and infectious diseases were increased in period of 2006-2008. In fact, 56% of all fish farms in 2006, 71% in 2007 and 85% in 2008 were recorded as infected farms. In other side, average weight of fish final products was more 500gr in consume market. So, regarding to long period of fish culture in mentioned fish occurrence of more morbidity could be expected. The streptococcus infections were most important fish bacterial diseases that have more incidence and pathogenicity in collected questionnaires. Also it revealed more occurrences in summer season in above 15oC temperature in affected fish farms. Also, Enteric Redmouth Disease (ERM) and Saprolegniasis were reported as second and third degree in examined farms. Meanwhile, findings of control, prevention and treatment of our survey revealed that using of antibiotics and detergent materials were increased in mentioned province. Indeed, 34.7% of all fish farms in 2006, 71.4% in 2007 and 75% in 2008 have applied treatment operation and using of detergent materials in affected farms. In other side, frequent using of Erythromycin antibiotic was reported several times in 2008 so fish farmer faced to Bacterial resistance and should be using from Florfenicol as alternative antibacterial. Also, in feed sampling from all fish farms about 3 fish farms in 2006 and 5 fish farms in 2008 were faced with food poisoning that originated from high TVN and peroxidase in fish food consumed. These farms revealed mass mortality that stopped after change feeding regime. In conclusion absence of fish health management could be considered as main agent of mentioned mortality in Mazandaran province. The findings of our survey in West and East Azerbaijan and Kurdistan revealed that absence of sufficient experiences in fish farmers and their neglect from water quality concepts, farm cleanness, using of suitable detergent materials for fish ponds and instruments and disability in continuous monitoring of physic-chemical factors of consumed water could be considered as most important problems. So, fish morbidity and mortality, growth decrement and low production rate were expected. Unfortunately, despite the occurrence of infectious and non- infectious diseases in examined fish farms, there were no documents and information about diseases history, clinical signs in dead fish, feeding regime, fish mortality (rate of daily mortality, age and weight of moribund fish), treatment operation, drugs usage, growth rate, physico-chemical factors and fish density. So planning for control and prevention of mentioned diseases were unsuccessful in affected fish farms. Also, occurrence of some epizootic fish viral diseases such as VHS, IPN and IHN were observed frequently with mass mortality about 40100% in some examined fish farms that produced some tragic economic lost in the mentioned provinces. Similarly, some bacterial, fungal and parasitic diseases were observed repeatedly in some inspected farms such as Flavobacterium, streptococcus infections. Also, some unknown causative agents in parasitic diseases were observed several times such as Dactylogyrus, Gyrodactylus, Ichthyophthirius multifiliis, Trichodina, Chilodonella, Diplostomum and fungal diseases such as Saprolegniasis. In conclusion it seems that absence of fish health management, inadequate rate of hygienic technical services, absence of quarantine programs for transfer of new eyed-eggs, juvenile and live broodstocks packages without health certificates from authorized organizations, uncontrolled entry of foreign eyed-eggs (France, Denmark, Australia and Armenia) and neglect in using of suitable detergent materials for fish ponds, instruments, consumed water and infected eggs, not screening of broodstocks in hatcheries could be considered as most important causative agents in occurrence of infectious diseases and main problems in affected farms in mentioned provinces. Similarly, our findings in Gilan and Ardebil provinces revealed that their problems were similar to other provinces. In fact, neglect in establish of necessary Infrastructures in fish farms and dereliction in health management concepts could be considered as main reasons of occurrence of fish infectious and non-infectious diseases in studied fish farms in mentioned provinces. In fact, often fish farms visited hadn't suitable structures without control and prevention approach. There were not observed detergent using, quarantine programs and prevention methods. Entrance of unknown persons, birds and wild animals were ordinary in mentioned farms. Unfortunately level of farmer’s knowledge was low and no training courses and extension programs were planned by authorized organizations. Meanwhile, food storages were unsuitable and food packages were stored in inappropriate situation so poisoning conditions were increased in examined farms. In conclusion it could be finalized that Coldwater fish farms in Gilan and Ardebil provinces situated in insufficient position and correction of current situation are needed urgently. In final elicitation, it would be mentioned that lack of basic infrastructures could be introduced as most important reasonfor spread of diseases, mortality and related economic losses in studied provinces. Therefore, attention to environmental affairs and access to Sustainable Development are recommended. Also consideration of biosecurity regulations and health management concepts would be important requirements for modification and reformation of Coldwater fish farms in examined provinces towards A Better Tomorrow.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: In this research was used sodium chloride in feed supplement to stimulate ion- osmotic regulation system of Rutilus Kutum juveniles (about one gram) in fresh water environment.The purpose of this experiment was to improve survival and growth ability of juveniles’ fish in brackish water during times of transition. The initial average weightes of Juveniles’ fish were 0.91±0.01 g (mean±SE). Experiments carried out in two phases. In step one, the Juveniles’ fish were kept for 15 days in fresh water and fed with commercial diet plus NaCl supplement (control without NaCl supplement, 5, 7 and 10 percent) in four treatments, each treatment inclusive three replication. In the second step, the fish transferred to brackish water (12.5 psu) and fed for 28 days with a commercial diet (without NaCl supplement). The results showed that no change compared to control treatment in renal tissue in step one. The difference between the kidneys were not in fish fed with NaCl supplement and without it. Nevertheless, a significant difference was observed between the size of the glomeruli and renal tubules between fresh and brackish water environments (between stage one and two), (P〈0.05). In step one, were observed in the gill accessory cells in treatments fed salt supplements. At the end of the second step, the number of gill chloride cells in fish fed with salt supplementation was more than control (P〈0.05). In addition, the highest and lowest weight gain was obtained in treatment two and four respectively (P〈0.05), and no significant difference was observed between control and treatment 3 (P〉0.05). The results showed that the fish fed dietary supplements of sodium chloride 10% versus the control treatment had less weight gain. Therefore, the was obtained the highest weight gain and growth performance (condition factor, specific growth rate) and the highest feed efficiency and protein efficiency ratio and the lowest feed conversion ratio in treatment 2 with the feeding of 5% NaCl in dietary supplements.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: The project is funded by the CASPECO Project which is the Third Phase of the GEF supported project in the Caspian Sea region titled “The Caspian Sea: Restoring Depleted Fisheries and Consolidation of a Permanent Regional Environmental Governance Framework” , and implemented by the Iranian Fisheries Research Organization (IFRO) in partnership with four Coastal Research Centers affiliated to IFRO, Coldwater Fishes Research Centre (CFRC).The project's objective is to improve the conservation and restoration of Caspian Salmon (Salmo trutta caspius) stocks. In accordance with IUCN criteria Caspian Salmon is placed in the red list of endangered fish. In the recent decades the destruction of habitats for juveniles, reduction of genetic diversity and fish immune system were main causes of the Caspian salmon decline. Numbers of public meetings were held with participation of fishing communities’ representatives, experts, relevant local authorities and experts of the IFRO and Iranian Fisheries Organization (IFO), Iran Environment Protection Organization (IEPO), Water Resource Management (Ministry of Energy) and University senior professors, in order to create interaction and understanding of the project objectives. Educational awareness and extension program were conducted with the involvement of fisheries communities, private sector and NGO associations. The results of the project suggests that cross-sectoral coordination for sustainable fisheries can be achieved through building partnerships and enhancing communication between the environment, private , fisheries sectors and academia. Cross-sectoral cooperation through this project improved public awareness on growing risks facing Caspian Salmon from different sources including local sources (illegal fishing and over-fishing, urban wastewater, environment destruction, industrial pollutants, pollution of air and water resources), new emerging and invasive organisms, climate change, implications of the Caspian salmon population decline on economic and social affairs of the people who depend on them for their livelihood and food security and their role in fish stock protection. The project, through its capacity building, extension and educational programs and efforts to link science to management, could translate scientific findings into an action agenda for managers and policy makers that can bring an improvement in the future of the Caspian Sea salmon stock.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: An artificial Reef is a fabricated, underwater structure, typically built for promoting marine life in areas of generally featureless bottom. Creating artificial reefs began from 2000 in southern provinces in Iran. This study has surveyed about the Bushehr and Khozestan states. The objective is to determine the effectiveness of artificial reefs in attracting and enhancing the production different aquatics through increasing of fish assemblage and fishery. The performance of artificial reefs deployed off the coast of the Persian Gulf in 10 to 15m, was evaluated. The reefs comprised of seven artificial and one control (natural) statistical tests plan in three replicates. Three types of artificial reefs were used in this study. That two were designed reefs and one was not designed or used material. The experimental plan consisted (i) Reef ball (R), designed hemispherical shaped; (ii) Laneh Mahi (L), designed pyramid shaped; (iii) Used material (U); (iv) mixed (RL); (v) mixed (RU); (vi) mixed (LU); (vii) mixed (RLU); and (viii) control site (CS). Trap nets and under-water visual census surveys were adopted for seasonal sampling of fish aggregation. Results of statistical analysis using ANOVA and T-test of the mean Catch per Unit Effort (CPUE) showed significant difference (p〈0.05) in term of computing number of fish for aggregation of fishes. The study has concluded that reef deployments have influenced favorably the fish communities and fish harvests. Therefore, the artificial reefs, especially the mixed RLU, are appropriate tools for future fishing enhancement in the Persian Gulf of Iran.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: This study aimed to determine domain the adaptability of rainbow trout(Oncorhynchus mykiss) fingerlings in fresh water up to 20 per thousand (grams per liter) for providing facilities for growing this valuable species in the aquatic environment with salinity unconventional been completed. For this purpose the biochemical, bloody and physiologic parameters rainbow trout were studied to determine the adjustment range .Fingerlings fishes from cold water fish farm in the province Mazandran were prepared and for experiments were transferred to the Ecological Institute of Caspian Sea . Fingerlings with an average weight 31.56 ± 0. 07 SE g and average fork length 13.80 ± 0.15 SE cm, in 3 treatments in water with salinities (fresh, 13 and 20 grams per thousand) with a density of 15 numbers in polyethylene to 300-liter tank containing the 250 liters of water testing were introduced.Fresh water from Tajan rivers and water psu13 from the water Caspian Sea and water psu20 by mixing water the Caspian Sea and Sea salt was prepared . The daily amount to 50 percent of the of water tankss been replaced .During the experimental period was for 7 days and were not fed during the experiment.The water parameters was measured during the experiment included 6 ppm dissolved oxygen, pH equal to 8.2 and temperature 15.5 ° C . In the experimental period were not observed Losses in the experimental groups . The results showed that fish gill and kidney introduced in different salinities by making appropriate changes in chloride cells in the gills through increasing the number and the volume of these cells at the base of secondary blades and tubules in the kidney tubules to create greater interior space, are adapted to By changing salinity.Relatively parameters osmolarity, sodium, chloride, magnesium, cortisol, calcium, hematocrit, hemoglobin,number of red blood and white cells in water saltier than freshwater environment was higher (0.05〈 p, Duncan). Changes in hematological and blood plasma ionic parameters and vital organs Fingerlings indicates a willingness adaptability and the ability physiological adaptation fingerling was consistent with changes to environmental salinity brackish water .So, the factors measured with increasing salinity the uptrend that the range of variation for the osmolarite 449-281 mOsmol kg, for sodium, chloride, magnesium, cortisol, respectively, 211- 151, 165121, 3 / 3 7/0, 87. 53 mmol and the calcium 22-13 mg per dL.The measured values for hematocrit 32.2- 38.8%, hemoglobin 6.2 - 8.6 g per deciliter and the red and white blood cells, was respectively, 1.2-1.7×106 and the 15.6 -18.9×103.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: The shrimp farming success in the future will greatly depend upon increasing supplies of healthy and high quality seed for stocking ponds. The limited and inconsistent availability of wild shrimp postlarvae together with an urgent need of establishing selective breeding programs, increased the interest in captive broods of penaeid. Many investigations have been carried out on several shrimp species world-wide. This study have been conducted on 2 shrimp groups since September (Mehr) to July (Tir) 1999 in Bandar-e-Imam southwest Iran. The wild group (SPB) prepared from Jask area and the pond group (POB) prepared from artificial ponds upon harvesting them as marketable size have been investigated. 2 groups were exposed to natural diets consisting of squid and artemia biomass in same conditions using 12 m3 concrete tanks. Stocking density was 2 piece/m2 (1F:1M). Half part of the pond bottom covered by fine sand to reduce the stress where the other part has been used for feeding. Daily ration given in 3 times by satiation method. Also reproductive performance of wild gravid brooders (WLB) were recorded as a control group. 2 examined groups well grown and around 50% of the SPM and around 30% of POB females successfully ripened a produced eggs and nauplii where almost all males of both groups were matured. Data showed fecundity is highly correlated to the TL and W of the brooders by positive trend. Considering the TL, W, Fecundity and nauplii production the WLB brooders are significantly (P=0.05) higher than 2 other groups, while the SPM broods are significantly (P=0.05) higher in hatchability. Meanwhile the survival rate from nauplii to postlarvae stage was around 30% for SMP brooders. On the other hand the growth parameters (TL, W) of the marketable size of the shrimps produced from SMP brooders were significantly (P=0.05) higher than those produced from WLB group. Since the fecundity is improvable by increasing the brood size thus the data suggest the sup.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published

Beschreibung: This Tajan river in / April/ 2000 and was followed to one year of Four stations selected from estuary to farah Abad station. Sampling occured to limited: (the survey of characteristic and choloride toxins in above limited in relative of three stations. Forty thousands species of Acipenser persicus fry with the different average weights were delivered fry were tagged and then the tagged fish were released in released stations in the different times. The fishing stations and the survival time in fry in the river, determination of upper and down streams in releasing area, Nutrition, Microbial diseases and estimation of catch populations in repeated fishing were evaluated. The physico - chemical characteristics of water and the evaluation of condamination were surveyed in the river. In addition, .the- evaluation of frequency and biomass (such as benthos and zooplankton were surveyed in the river). Finally, the effective factors in the mortality of fry in relative before and after releasing, the best place for releasing area of fry in the river was introduced into execution selection. The survival time of fry is low in the river and it depends on the distant between from the releasing area to estuary and the releasing time. Fry were passed from estuary after 24 hours and fry were approached to the sea after 48 hours and also the peak migration of them has been from 12 p.m to 3 a.m. The internal migrations don't have toward Upper River and these migrations have toward the sea. Fry haven't fed in survival time but after fourteen days, they caught in coastal section. The gammaridea and hypania (type of hypercilia) were fed by them. Before the releasing, fry have been contaminated by bacterial agents. The contamination rate was 3.3% but after releasing and passed from estuary have not been contaminated. The survey of the chemical and physical features in area indicated that the salinity was ascended higher than six ppt in third decade of April. The other factors indicated a healthy ecosystem. Of course, the increasing of salinity was related to Debi in water that approached to zero. The survey of choloride toxins in water indicated that were lack of difficult survey area in rivers. These toxins have been compared to another toxins such as hexa - choloro - benzen (a -HCB) that this concentration has a high in estuary. The evaluations the biomass of nutrition (Benthos and zooplankton) in the river indicated in the relative to benthic condition was included six classes. They contain bottom invertebrates, they have been identified 11 families and 9 species and so they consist of Insecta, Olighocheata class, Crustancea class, hypercilia class, Crustacea class, Bivalva class, Gastropoda class, it is obvious that the estuary station have a high biomass of benthic organisms and it has higher variation species than other stations. The zooplankton condition, In addition, it is belong to zooplankton that was identified to Rotatoria - Cladocera - Copepoda- Barnacles - Protozoa and forminofera as the beginning of spring season. Zooplanktons have a high variation but the end season, they have a below amount. Although, the gill net has one (cm) in mesh that sturgeon fry entrapped them the main effective factor of mortality about sturgeon's fry took place when sturgeon's fry entered into the sea. But the qoopegative company net of fishing, sturgeon's - fry caught in by catch that this agent were threatened when sturgeon's fry entered in to the sea. The evaluating of two stations for releasing the fry (research and farah Abad stations), the .research station (distance 500 m from estuary) has the best area for the releasing. the sturgeon's fry (fingerling) was introduced into the excution section . Key word Tajan river, Acipenser persicus (Sturgeon's fry gillnet) - nutrition, Microbal diseases, Choloride toxins.

Beschreibung: Iranian Fisheries Science Research Institute

Beschreibung: Published