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In this investigation which had been done in commercial catch regions (where discharged theirs catch) in three ports Babolsar, Amirabad (in mazandaran) and Anzali (in Guilan).The main objectives of the present study were to estimate of catch and catch per unit effort, von Bertalanffy growth parameters, condition factor, sex ratios, spawning, biomass and maximum sustainable yield of common kilka in Iranian waters of the Caspian Sea. The result shown that catch of kilka in Iranian coastal in 2015 increased from 21553 ton to 22428 ton in 2016 and CPUE was 2.6 and 2.7 ton (Vessel ×Night) respectively . Common kilka was the predominant all months of the year about 98 percent. The mean length was 103±9.6 at the same time and range length 92.5–112.5 mm were the dominant population (about 82%). The mean condition factor was 1.38±0.1 . Age abundance during this period have not been substantially changed and always fishes with 3 and 4 year olds had the highest frequency78.5 and 76.8 percent respectively. The parameters of the Von Bertalanffy growth curve were 138[1 exp ] 0.251( 1.124)   t Lt for common kilka. The instantaneous coefficient of natural mortality (M) was 0.506 yr-1 . The instantaneous coefficient of fihing mortality and total mortality were 0.753 yr-1 and 1.259 yr-1 , respectively. The exploitation rate of common kilka were 0.60 during 2015-2016. In the years 2014-2015 and 2015-2016, the biomass of common kilka was estimated 86401 and 71671 ton, respectively. In these years, fish of the 2nd and 3rd year of this fish had the highest amount of reserves (respectively 29025 and 24632 ton) and The lowest reserves for 6-year-old fish, respectively, were 772 and 355 tons respectively. The breeders biomass of this species is 37132 and 34390 tons respectively and The ratio of biomass of broodstocks to the whole was 43% and 48% respectively. Acceptable Biological Catch was estimated with a precautionary approach of 18,400 tons. The average catch of this species on the coast of Iran in the last 10 years has been more than 21,000 tons, and in fact, the optimal level of harvesting from the reserves has not been observed. It should be noted that when exploiting a storage facility, excessive harvesting of the harvestable product will lead to the destruction of longterm storage. Iranian Fisheries Science Research Institute Published

This study was conducted to determine the opening and closure of Penaeus semisulcatus fishing season in July, August and September during 2012 - 2014 in the waters of the Bushehr province . 30 stations were hauled based on a Stratified Random Sampling design in three depth layer of less than 10, 10-20 and more than 20 meters. The optimum dates of opening shrimp fishing season for the years of 2012-2014, were calculated as 4th, 28th and 13th July respectively. The closures of Shrimp fishing season for years of 2012-2014 were determined to be 10th September, 29th of August and 5th of September. The estimated biomass were for all of shrimp species in the years 2012-2014, 930, 1009 and 526 tonnes respectively. Penaeus semisulcatus contributed 92, 96 and 99% of the shrimp stock in the mentioned years.The CPUE (catch per hour) were calculated to be 1.6, 16.9 and 6.9 kg per hour, in the years 2012-2014, respectively. The highest aggregation of Green tiger Shrimp (P. semisulcatus) were observed in 10-20 depth meters layer in southern waters of Bushehr province at the fishing areas (Motaf to rostami). The changes in climatic conditions resulted in differen dates of the opening season and probable illegal fishing may have caused the reduction of shrimp biomass in recent years. Hence to Protect the stocks the economic species and the sustainability of shrimp fishing, it is neccesary to properly manage fisheries and determine the opening and closure fishing season Penaeus semisulcatus through conducting research surveys. Iranian Fisheries Science Research Institute Published

Biomass estimation of fishes were done by depletion method in Shadegan Wetland in 2011-12. Fishing effort and landing catch amount per unit effort was done via random oversea in fixed landing area monthly. Fishermen and catch statistics were obtained from census. Total catch was calculated from multiplication of effort and average catch. Fishes biological characteristics survey indicated that Golden barb (Barbus luteus) and Berzem (Barbus pectoralis) has maximum (62 kg/ha) and minimum (4 kg/ha) biomass respectively. Maximum and Minimum biomass was in spring (380 kg/ha) and in winter (58 kg/ha) respectively and mean biomass was estimated 249 kg/ha in whole area during one year. Number of fishermen were about 1317 and maximum fishing effort was in April, May and June. Total fish landing was 4300 tons per year in which 1119 tons was calculated in April. Large scaled barb (Barbus grypus) and Abu mullet (liza abu) had maximum and minimum mean length and weight. The range length of most of fishes was low and their spawning season was in winter and spring. Length- weight relationship indicates their isometric growth. Despite of 45% decrease of number of fisherman to previous time (2008), catch effort and exploitation was increased (20%). Regarding fish living area (70000 ha), total biomass was 17430 tons.

Biomass estimation of fishes were done by depletion method in Shadegan Wetland in 2011-12. Fishing effort and landing catch amount per unit effort was done via random oversea in fixed landing area monthly. Fishermen and catch statistics were obtained from census. Total catch was calculated from multiplication of effort and average catch. Fishes biological characteristics survey indicated that Golden barb (Barbus luteus) and Berzem ( Barbus pectoralis ) has maximum (62 kg/ha) and minimum (4 kg/ha) biomass respectively. Maximum and Minimum biomass was in spring (380 kg/ha) and in winter (58 kg/ha) respectively and mean biomass was estimated 249 kg/ha in whole area during one year. Number of fishermen were about 1317 and maximum fishing effort was in April, May and June. Total fish landing was 4300 tons per year in which 1119 tons was calculated in April. Large scaled barb ( Barbus grypus) and Abu mullet (liza abu) had maximum and minimum mean length and weight. The range length of most of fishes was low and their spawning season was in winter and spring. Length- weight relationship indicates their isometric growth. Despite of 45% decrease of number of fisherman to previous time (2008), catch effort and exploitation was increased (20%). Regarding fish living area (70000 ha), total biomass was 17430 tons. Iranian Fisheries Science Research Institute Published

This study was conducted to determine growth parameters, catch and fishing effort trends, stock assessment and Acceptable Biological Catch (ABC) of Caspian Sea mullets in the Iranian coastal waters of Caspian Sea in the fishing season of 2012-2013. For gathering of data on biometry and catch statistics, 5 mobile working group in the regions of Anzali, Kiashahr, Nowshahr, Babolsar and Torkmen were involved from the start to the end of fishing season.Gathered data Were entered to the computer. For data analysis, common methods were undertaken for estimation of growth parameters, mortality rates, biomass and Maximum Sustainable yield (MSY) and Acceptable Biological Catch (ABC) as well. According to the result, the number of beach seines cooperatives was 124 and fishing efforts were 45260 beach seining haul. The catch per unit of effort CPUE) was calculated 37 kg/haul during this fishing season. The total catches of Caspian Sea mullets (including illegal fishing estimated as 2151 mt. Growth parameters of golden gray mullet (Liza aurata) were estimated as K=0.12 /yr, L_∞=59.24 cm, t_0 = - 1.31 /yr. Based on catch-at-age data, in the fishing season of 2012-2013 , the total biomass, from the biomass-based cohort analysis were estimated 11321.6 mt. The reference points of F0.1 and F30% were estimated 0.3 /yr . based on these results , the fishing mortality rate in fishing season of 20122013 were very closed to these reference points. In this survey , the Maximum sustainable yield and Acceptable biological catch were estimated as 2207.7 and 1981.4 mt respectively .Results of biometry of leaping gray mullet (Liza saliens) showed that the mean length and weight of this species were 28.8 ± 3.4 cm and 230.5±74.8 g respectively. Based on these results and due to decline of golden gray mullet stocks, it is recommanded to reduce fishing effort and harvest keep to the level of MSY and ABC .The study of spawing condition of golden gray mullet in new situation of this species is also recommanded.

This study was conducted to determine the opening and closure of Penaeus semisulcatus fishing season in July, August and September during 2012-2014 in the waters of the Bushehr province. 30 stations were hauled based on a Stratified Random Sampling design in three depth layer of less than 10, 10-20 and more than 20 meters. The optimum dates of opening shrimp fishing season for the years of 2012-2014, were calculated as 4th, 28th and 13th July respectively. The closures of Shrimp fishing season for years of 2012-2014 were determined to be 10th September, 29th of August and 5th of September. The estimated biomass were for all of shrimp species in the years 2012-2014, 930, 1009 and 526 tonnes respectively. Penaeus semisulcatus contributed 92, 96 and 99% of the shrimp stock in the mentioned years. The CPUE (catch per hour) were calculated to be 1.6, 16.9 and 6.9 kg per hour, in the years 2012-2014, respectively. The highest aggregation of Green tiger Shrimp (P. semisulcatus) were observed in 10-20 depth meters layer in southern waters of Bushehr province at the fishing areas (Motaf to rostami). The changes in climatic conditions resulted in different dates of the opening season and probable illegal fishing may have caused the reduction of shrimp biomass in recent years. Hence to Protect the stocks the economic species and the sustainability of shrimp fishing, it is necessary to properly manage fisheries and determine the opening and closure fishing season Penaeus semisulcatus through conducting research surveys.

This study was conducted to determine growth parameters, catch and fishing effort trends, stock assessment and Acceptable Biological Catch (ABC) of Caspian Sea mullets in the Iranian coastal waters of Caspian Sea in the fishing season of 2012-2013. For gathering of data on biometry and catch statistics, 5 mobile working group in the regions of Anzali , Kiashahr , Nowshahr , Babolsar and Torkmen were involved from the start to the end of fishing season.Gathered data Were entered to the computer. For data analysis , common methods were undertaken for estimation of growth parameters , mortality rates , biomass and Maximum Sustainable yield ( MSY ) and Acceptable Biological Catch ( ABC ) as well. . According to the result, the number of beach seines cooperatives was 124 and fishing efforts were 45260 beach seining haul . The catch per unit of effort CPUE) was calculated 37 kg/haul during this fishing season . The total catches of Caspian Sea mullets (including illegal fishing estimated as 2151 mt. Growth parameters of golden gray mullet ( Liza aurata ) were estimated as K=0.12 /yr, L∞ = 59.24 cm, t0 = - 1.31 /yr. Based on catch-at-age data, in the fishing season of 2012-2013 , the total biomass, from the biomass-based cohort analysis were estimated 11321.6 mt. The reference points of F0.1 and F30% were estimated 0.3 /yr . based on these results , the fishing mortality rate in fishing season of 20122013 were very closed to these reference points . In this survey , the Maximum sustainable yield and Acceptable biological catch were estimated as 2207.7 and 1981.4 mt respectively .Results of biometry of leaping gray mullet (Liza saliens) showed that the mean length and weight of this species were 28.8 ± 3.4 cm and 230.5 ± 74.8 g respectively . Based on these results and due to decline of golden gray mullet stocks , it is recommanded to reduce fishing effort and harvest keep to the level of MSY and ABC .The study of spawing condition of golden gray mullet in new situation of this species is also recommanded . Iranian Fisheries Science Research Institute Published