Monitoring of tuna resources (yellowfin and skipjsck tunas) in Oman Sea along Sistan & Balouchestan coastal waters

Collecting of biometric parameters and catch and effort data were made for yellowfin and skipjack tunas from artisanal gillnet and industrial purse seine fisheries during the years 2002-2004 in Oman Sea along Sistan and Balouchestan coastal waters. The previous available data was used for the purpose of better monitoring the resources. The frequency of maturity stages and GSI values obtained from yellowfin showed a spawning period from February to May, peaking in April-May. For skipjack, the data indicated a long spawning period which beganed in December with peaking in April-May. LM50% was obtained as 83.1 and 62.4 for yellowfin and skipjack tunas respectively. Sex ratio by size group showed a predominance of males with larger fish. Analysis of stomach contents showed a significant proportion for the both species. The composion of food contents by occurrence method revealed that fish were the most dominant food items by year for the specise. Presence of squilla, crabs, shrimps (Larval stage), belonging to Peneaidea family, in large quantities were the oblivious food items so that they had not been reported by previous studies. Blooming of squilla, Natosquilla investigators, in the western Indian Ocean provided a situation to be observed in large occurrence in yellowfin and skipjack stomach contents. The ratio was more in yellowfin stomachs when compared to skipjack ones which accounted for 38%, 19% and 35% of the total stomachs studied by the study year. The shrimps prey were only observed in skipjack gut contents (with exception of one case in yellowfin stomach) which were the second major component in 2002 and 2003(24% and 17% respectively). Comparsion of mean length showed a sharp decrease from 1992 to 2004 for the species. Regarding yellowfin the mean length from 93.2 cm FL in 1992 reached to 83.2 cm FL in 2004 and from 64.95 to 58.51 cm FL for skipjack. In spite of decreasing mean length for yellowfin, the value increased in 2004 in comparison to 2003 which was in agreement with Indian Ocean data. Comparative analysis of length frequency with LM50% indicated that immature fish were the major part of the catch. There are available information on population dynamic parameters. A comparative analysis of CPUE,s (kg/panel.day) from artisanal gillnet fishery for yellowfin and skipjack tunas revealed a decreased value by fishing craft class in 2005 when compared to 1998 data, but increased in 2003. Increased trend of the species catches by fishing craft class was due to increased fishing effort. Analysis of the statistical catch and effort data for the study years, irrespective of fishing craft class, showed that total landings of the species have increased 4.4 fold in spite of attaining CPUE to 7% in decrease which was a consequence of increased fishing effort up to 4.7 fold. The CPUE, s (tons / positive set) from industrial purse seine fishery increased in 2003 and 2004(39% and 10% respectively), but declined up to 54% in 2005. The trend is in agreement with purse seine fishery data from Indian Ocean where the increased values were attributed by larger size of yellowfin. The purse-seine fishing ground data revealed that the major sets were made in Persian Gulf, whereas a shift towards Oman Sea in eastern part of Sistan and Balouchestan coastal waters is recommended to be a suitable fishing area for the first half of year and towards offshore waters in Indian Ocean for the second half of year. For attaining a sustainable fishery system, it is recommended to regulate the gillnet mesh size and introduce longline fishery in the area along with stopping any further increased fishing effort in artisanal gillnet fishery

Monitoring green tiger prawn stock in Bushehr Province waters

The results of 30 months of trawl sampling on P. semisulcatus, De Hann 1848, obtained through operational phase of MONITORING GREEN TIGER PRAWN RESOURCES project, along with results of another available 28 months of the data of the same structure prior to this, has formed an invaluable time series of data as a proper basis for the further analysis. The survey area is located at North-west of the Persian Gulf from Bahrekan to Dayer waters. The ultimate goal of this study is to come to a better understanding of behavioral pattern of Green Tiger Prawn in its exploited phase after recruitment to the fishery. In this study, the confirmation of the life cycle of P. semisulcatus, to the general life pattern of Penaeidae shrimps was observed. Of the peculiarities of this pattern are the yearly bi-modal spawning and two corresponding peaks of recruitment. There exist two spring and autumn generations, which the major spawning in autumn produces the main recruitment in summer and the autumn generations stem from spring spawning. The spatial and temporal distribution of shrimp is highly variable by month and year. Depending on the year, higher shrimp densities are often found in early summer between Lavar and Rostami and/or Rostami to Bushehr and extend north and south in August. This result can be used in better design of sampling scheme for nursery studies. The main recruitment, which the fishery is depended upon, is in July to August and a second one occurs December-February. The timing and strength of both recruitments vary inter-annually. The proportion of prerecruits in southern area is always higher and the modes more prolonged than in northern area. The period of major recruitment starts earlier and lasts longer in the south than the north. A consistent pattern is not seen for the secondary recruitment, which, usually occurs in December-January. It is hypothesized that 1- the secondary recruitment might occur in Kuwait and/or Saudi Arabia waters, 2- insufficient number of spawners in spring or 3- high mortality in summer could cause the weakness of secondary recruitment. The spatial distribution of the mature female shrimps in spawning months indicates that the northern part of study area is an aggregation ground. It is also found that this aggregation grounds are close to two main fresh water sources (Helleh and Mond rivers), and these phenomena can be somehow related. The average length at 50% maturity varies inter- annually and is estimated to be 15.3 Cm. Length-frequency distribution of shrimps by sex reveals 1 to 3 modes depending on the month and year. In southern part a more complicated and less consistent pattern of recruitment and growth between years was observed. There is multiple or/and continuous recruitment especially during summer months. The von Bertalanffy growth parameters were estimated. The Findings are used to design new sampling schemes to cover the whole life cycle of this species enabling one to explain the variations in their response to the environment and fishery. The results of this study, lead us in building appropriate assessment and management models

Feasibility study on development of artificial reefs in the Persian Gulf (Hormuzgan province)

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 fauna 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

Stock enhancement and estimation of growth rate of green tiger prawn (Penaeus semisulcatus) and banana shrimp (Fenneropenaeus merguiensis) released in the Persian Gulf

Present study was conducted in the Persian Gulf (Iranian waters) from 2009 to 2012. The main objective of the research was economical evalution of the stock enhancement of banana prawn (Fenneropenaeus merguiensis) and green tiger shrimp (Penaeus semisulcatus) in the studied area. Also tagging effects on the growth and mortality of tagged shrimp were studied. In banana prawn, broodstock shrimps were hatched in June. In July 2010 and 2011some of the juvenile of this species were marked by red fluorescent liquid injection and released were made at night in the estuaries of Tiab, Kolahi and Koolgan in the Hormozgan province. 84000 juveniles of banana prawn in 2010 and about 50000 in 2011 were released in this area. In Bushehr province waters, adults shrimp were reared and when juveniles reached to optimum size, some of them were tagged by red and blue coloures and were released in the coastal waters of Bandargah and Delvar. Tagging and releasing program of green tiger prawn was performed in 2010 and 2012. A total number of 8000 prawn in 2010 and about 30000 juveniles prawn in 2010 were released. Activities for recaptured shrimps were informed by posters describing the tagging program that were distributed to local peoples, as well as local magazines, and a tagging program awareness film was broadcast on national television three times prior to the shrimp fishing season and during catch season. To encourage people to report recaptures a reward of two handered thousent riales was paid for the return of each marked shrimp accompanied by information. Economical evaluation of banana prawn was performed based on releasing and recaptured program in 2011. As it mentioned in this year 50000 of juvenile shrimp were tagged and released. At the same time 4700000 of unmarked shrimp were released in this area. In the shrimp season 11 (./022%) of tagged shrimp were recaptured. Movements of tagged shrimp were northwesterly to released area. Weight average of tagged prawns was 1.2 gram. Mean weight of the recaptured prawns was 22.06±4.9 gram. Body weight Growth of the recaptured prawns was between 16-26 grams with the growth speed of 0.88-1.41 per week. The number of recaptured prawn to the released prawn was 0.022 percent. Based on the released prawns (4700000) to the recaptured percent (./022%), about 103400 of released shrimp with mean weight of 2.5 tones were observed in the Hormozgan shrimp catch. The average price of shrimp in the studied year in the local market was 85000 Rials per kilogram. These results showed that the ratio of profit is 210 milion riales. In the taggiing program of green tiger prawn in the Bushehr waters only one recaptured shrimp was observed in the catch season (2012). Total weigth and total length of this prawn was 99 gram and 22 centimeter respectively .given the small percentage of the recaptured, economical analyses was not performed on this species. The effects of tagging on the growth and mortality of green tiger prawn were studied. The present study was carried out in the shrimp research station in Bandargah and Abzistan shrimp Hatchery Company in Delvar during 2010 and 2012. The accuracy of the study was more rialable in 2012. In this year growth and mortality of juveniles that was marked by red and blue coloures, were studied in both area Bandargah and Delvar. In Bandargah, three tanks of 300 l each with 30 specimens were used for untagged shrimp as a control group, and tagged with injected liquid fluorescent during 98 days. Length and weigh of 10 specimens were measured evenly in different times. ANOVA results (α = 0.1 and α = 0.5) showed no significant differences between length growth of tagged shrimp and control group. The mortality of two groups was evaluated by numbering of remained shrimps and the average of survival was 52 percent in the tagged and 44.5 percent in tagged shrimps. In the Delvar station, Abzistan Company, the specimens were kept in the 9 tanks each 300 l that included of 30 untagged shrimps, 30 blue tagged shrimps and 30 red florescent tagged shrimp. The growth and mortality of this station were evaluated during 110 days. The growth rate of the specimens were measured and recorded evenly. The results of ANOVA (α = 0.1 and α = 0.5) showed no difference significantly in the weight growth of tagged and control groups. The mortality rates among the control group, red tagged and blue tagged were 63 percent, 59 percent and 40 percent. The mortality of the groups was differences in the two stations and it seems the management and environmental conditions were more affected on the mortalities. The results of the study show that the ratio of profit to the coast is 0.46 that is covering half of the coasts, so that the expenditures are two times more than profit. This result is the minimum of economical value of stock enhancement of shrimp. The results of study showed that the injected tags into the body tissue of shrimp has no affected on the growth rate and mortality

Biomass estimation of demersal resources in the Persian Gulf and Oman Sea by Swept Area Method

Regarding to monitor of demersal resources in the Persian Gulf and Oman Sea, and also biomass and CPUA estimation of them, a series of research cruises (5 cruises per year) were carried out by R/V Ferdows-1covering the area from 49 00 E in the west (Khoozestan provice) to 61 25 E in the east (Gwater) in a 5 years program form 2004 up to 2008 (no cruise in 2006). The study area was stratified into 17 strata (A to Q) of which 10 starta (A to J) were in the Persian Gulf and 7 strata (K to Q) were in the Oman Sea, covering the depths of 10-50m in the Persian Gulf and 10-100m in the Oman Sea. A total of 316 stations were randomly selected. The biomass and CPUA were estimated by Swept Area method. The comparison between two regions indicated that the percentage of density of demersal fishes in the Persian Gulf during years 2004, 2005, 2007 and 2008 were 3.3, 3.9, 2.3 and 2.4 times more than the Oman Sea and totally 70-80% of total biomass was calculated for the Persian Gulf. Also a comparison among 17 starta, the highest biomass was found for starta C & D in the Bushehr province waters. The amount of CPUA for both regions of the Persian Gulf and Oman Sea was compared and it was concluded that in years 2004 and 2005, the mean CPUA in the Persian Gulf was partially higher than the Oman Sea with 1.06 & 1.20 times more; and on the contrary for the next two years this value was higher in the Oman Sea with 1.3 times more. The highest CPUA of demersal resources for the Oman Sea belonged to the strata K & O for years 2004, 2007 and 2008 and for year 2005 was for L and strata. It can be concluded that the north-west of Oman Sea has the best condition of biomass of commercial and non-commercial species and the O stratum will be in the second ranking. With review the mean CPUA in different depth-layers for years 2004, 2005, 2007 and 2008, it was concluded that with increasing the depth, the mean CPUA is decreased in which the CPUA values in depth-layer 10-20m for these years were 8.3, 3.0, 2.1 & 1.6 times more than depth-layer 50-100m. The comparison of mean CPUA for 10 strata of the Persian Gulf showed that in years 2004 and 2005, the mean CPUA of demersal fishes in the Hormuzgan province waters was higher than in Bushehr province waters (1.2 times more). In total, the highest maen CPUA belonged to F (Naiband to Mogham) and G (Mogham to Farour) in Hormuzgan waters. On the contrary, in years 2007 and 2008 this value in Bushehr waters was 1.3 times higher than western part of Hormuzgan waters with the highest value in D stratum(Boordekhoon to Dayyer). Also the comparison of mean CPUA for different depth-layers, it was found that the mean CPUA has ascending trend with increasing the depth, with the highest value in depth-laer of 30-50m in which contains the 55-68% of total biomass. The lowest biomass is found in depth-layers of 10-30m. Totally, the minimum CPUA and biomass for both commercial and non-commercial species belonged to a stratum located in Khouzestan province waters and it was shown the over-exploitation of resources in this area. The comparison between commercial and non-commercial groups in both ecosystems , it was concluded that the density of commercial species was higher than non-commercial ones , and in all years the Persian Gulf indicated higher values than the Oman Sea

Ecological interaction between commercial fishes in the Persian Gulf

An ecosystem-based management fishery is a new way of looking at management of living resources. Trophic levels of basic food items, feeding habits, growth and mortality rate of 20 exploited fish species (including commercial and bycatch) are investigated in the Persian Gulf (from the provinces of Khuzestan, Bushehr and Hormozgan) from 2010 to 2012. The model considers trophic interactions among 12 functional group of the ecosystem involving Phytoplankton, Zeoplankton, Cephalopods, Shrimp, Infauna Benthos, Epifaunal Macrobenthos, Demersal Zoobenthos Feeders, Small Pelagic Planktivorous Fish, Benthoplagic Feeder, Piscivorous, Large Benthic Carnivores And Small Benthic Carnivores. In general 7452 of stomach contents samples were analyzed based on the weight and numerical method and were detected about 40 preys. The results demonstrated gaps in our knowledge on the food web structure. The mean trophic levels were varied from L. klunzingeri (2) to S. tumbil (4.64), while the total catch of some species were fluctuating widely. Result of our study showed that Total mortality varied between 0.45 per year (A. suppositus) to 9.5 per year (P. indicus) and food consumption rate also fluctuated by 1.9 (L. johni ) to 89 (L. lineolatus). The results indicated that some fish species including sardine, Anchovies, small carangids, S. stridens with high frequency in ecosystem, have been occupied in the food web as a wasp-waist. The model showed that most hunters groups live in middle levels in the food web such as N. japonicas, A. latus, P. kaakan, L. nebolusus, P. indicus and T. lepturus . Analysis the catch rate during 2001-2011 reveled that there is a clear trend of declining most of fish species catches in this research except for T. lepturus, P. kaakan and sparids which lead to upset the fundamental ecological balance of the Persian Gulf in future

Biomass estimation of demersal resources in the Persian Gulf and Oman Sea by swept area method

Regarding to monitor of demersal resources in the Persian Gulf and Oman Sea, and also biomass and CPUA estimation of them, ten research cruises were carried out by using R/V Ferdows-1 equipped with bottom trawl, covering the area from 49º 00´ E in the west (north-west Persian Gulf) to 61º 25´ E in the east (borderline with Pakistan) from 2012 to 2014 The study area was stratified into 17 strata (A to Q) of which 10 strata (A to J) were in the Persian Gulf and 7 strata (K to Q) were in the Oman Sea, covering the depths of 10-50 m in the Persian Gulf and 10-100 m in the Oman Sea. A total of 316 stations were randomly selected and the biomass and CPUA were estimated by swept area method during this three years period, the strat A and B weren’t covered. The comparison between two regions indicated that the percentage of density of demersal fishes in the Persian Gulf during years 2012, 2013 and 2014 were 1.0, 1.4 and 1.6 times more than the Oman Sea and totally 50-60% of total biomass was found for the Persian Gulf. Also a comparison among 17 strata the highest biomass was found for K region (Sirik to Jask) in the Oman Sea in 2012 & 2014; and C region (Genaveh to Bordkhoon) in 2013 in the Persian Gulf. The same comparison was done for CPUA of commercial, non-commercial and total in both water bodies and it was found that in years 2012 to 2014 the region K (Sirik to Jask) in the Oman Sea and Stratum Q (Bersi to Gwatr) had the highest value of CPUA. On the contrary, the stratum M (Biahi to Galak estuary) showed the lowest value of biomass for both commercial and non-commercial fishes. With review the mean CPUA in different depth layers for years 2012, 2013 and 2014, it was concluded that in the Oman Sea with increasing the depth, the mean CPUA is decreased and the lowest CPUA belongs to depths of 30-50 m The comparison between commercial and non-commercial groups in both ecosystems, it concluded that the density of commercial species were higher than non-commercial ones; and for years 2009, 2010 and 2011 the commercial species consist of 63.4, 65.0 and 59.7 % of total biomass. In all years the Persian Gulf indicated higher values than the Oman Sea. The most abundant fishes were Rays, Ribbon fishes, Carangids, Grunts, Japanese threadfin bream, Lizardfish and Barracuda for both Persian Gulf and Oman Sea

Survey on health status in aquaculture sturgeons centers (Mazandaran, Guilan And Golestan Provinces)

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 ×10^5, 4.8±0.5×10^5 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)

Study on viral nervouse necrosis (isolation, characterisation and pathogenesis) in golden grey mullet in the Caspian Sea and study of pathogenecity and possibility of transmission to the other fish species (Sturgeon fishes, Rutilus frisii kutum and reared Rainbow trout and Carp)

Study on Viral Nervouse necrosis (isolation, characterisation and pathogenesis) in Golden grey mullet in the Caspian Sea and study of pathogenecity and possibility of transmission to the other fish species (Sturgeon fishes, Rutilus frisii kutum and reared Rainbow trout and Carp) Viral Nervous Necrosis (VNN) is a worldwide disease affecting several species of cultured marine fish. For the past two decades, betanodavirus infections that cause Viral Nervous Necrosis (VNN) have emerged as major constraints on the culture and sea ranching of marine fish in almost all parts of the world. More than forty species mainly of marine origin have been so far affected and this number is likely to rise in future following the introduction of new species and the increase of aquaculture trade. Unknown acute mortality occurred in wild golden grey mullet Lisa auratus and Liza saliens in Iranian waters of Caspian Sea in recent years. In order to isolation and confirmation of causative agents of golden grey mullet mortality in the Caspian Sea, a complementary research investigation project was designed in 2005 and approved immediately in Iranian Fisheries Research Organization (IFRO). Many diagnostic aspects such as Virology (Cell culture and Elctereone Microscopy), Hemathology, Bacteriology, Histopathology, Molecular biology (NestedRT-PCR), Heavy metals measuerment and Serology (IFAT and IHC) were employed in mentioned multidiciplinary project. About 322 moribund fish samples which revealed skin darkening, erratic swimming behavior such as spiral and belly-up at rest and high distention of swimming bladder. Suspected samples were collected from coastal capture sites in iranian north proviences in 2006 till 2009. Targets tissue such as brain and eye were removed in strile condition and then kept in -80oC frezzer for cell culture and Nested-RT-PCR. Other tissue samples from liver, kidney, intestine, stomach, gill, skin and muscle, gall bladder and gonads were taken and fixed in 10% buffer formalin and same parts fixed in glutaraldehyde 3% for histopathology, IHC and EM respectively. Cytopathic effect (CPE) was observed in those cell cultures just six days after inoculation with the dilutions of the tested 312 homogenate supernatants. CPE in monolayers of cells cultured (SSN-1 cell line) was characterised by thin or rounded, refractile, granular cells with vacuoles. Nine samples were positive in virology assay. Nested- RT-PCR was done on suspected tissue samples and supernatant of CPE positive samples and 21 tissue samples and all CPE positive samples were positive. IFAT was selected as a confirmatory method for identifying viral strains replicating on cell cultures and carried out with rabbit anti-betanodavirus serum on suspected tissue samples and some smears of CPE positive samples. Some bright points approved betanodavirus antigen and confirmed cell culture and Nested-RT-PCR findings. In fixed tissue samples widespread and massive vacuolation were observed in brain, spinal cord, retina and optical nerve. In order to confirmation of diagnostic findings , IHC was done with monoclonal antibody antibetanodavirus and some red-brown points were observed. Theses findings revealed expected viral antigens and confirmed previous results. Moreover, virus particles with 25-30 nm in diameter were visualized in infected brain and retina using positive staining in TEM. Also pathogenicity test was employed to confirm the obtained results. So Guppy fish Poecilia reticulata and sturgeon fry were used instead of the experimental host due to ease of handling and susceptibility. After 15 days post infection, guppy bathed in VNN-infected tissue culture with 104 TCID50 showed clinical signs similar to naturally infected Golden grey mullet, and the mortality rate reached up to 100% in 75 dpi. When target organs were examined by cell culture isolation, serology, and histopathology, all revealed the presence of virus in the Guppy. Suspected supernatant injected to sturgeon fry through intravitreous injection and widespread vacuolation were observed in brain and spinal cord buy IHC and Real time PCR were negative. In conclusion, with attntion to obtained results in this investigation such as ecological factors, clinical signs, histopathological, virological and bacteriological results, molecular analysis, (IHC, IFAT, PCR), TEM demonstration, serological and hematological findings, it could be confirmed that VNNV was the main causative agent for disease outbreak in Golden grey mullet in Southern coastline of Caspian Sea

A survey on health status of coldwater rearing and hatcheries fish farms in Iran (Mazandarn, Gilan, Ardebil, West Azerbaiejan, East Azerbaiejan and Kordestan provinces)

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