ALBERT

Description: 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 .

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: To accomplish the stock assessment that pre-planned for bony-fish resources investigation started by considering two pivotal act. First gathering biometric data and second using catch statistics information for stock analyses. Implementing the research programmes five itinerant groups in Anzali, Keyashahr, Noshahar, Babolsar, Torkaman have been organized during fishing season. The biometric data were supplied in computer that distincted by each fish species and subdivided into age groups. In analyses the samples, Bertalanffy formula used for calculating average length and age, also for growth coefficient. Total mortality rate calculated by using Pauly formula, and the biomass status estimated through Cohort analysis. The catch by beach seiner cooperatives recorded 8630 metric tons, but estimation including. Poacher catch raised the harvest to 15.6 thousand tons. The total catch of Kutum reduced by 1400 tons compared with previous year, but the estimation revealed the biomass of Kutum 18.5 thousand tones, the stock stowed reduction in quantity relative to past years. Harvest exceeding the limit, fishing pressure. And employing higher fishing effort, combining releasing the Kutum seedling with shorter average length in recent years, leaded the shrinkage of biomass of Kutum resources. The Golden Grey mullet catch has been estimated 3437 metric tons, the figure showed 1500 tons increment, in comparison with previous year, nearly 24% of catch was shorter than Lm50% of this species. In Guilan province higher number of sub - size golden mullet captured, this development occured less in Mazandaran and Golestan province. Higher rate of exploitation, reduction of catch in recent years, dominating small size fish in catch composition indicated the population undergoing stress in ecosystem. Thin - lipped grey mullet only comprised 9.2% of the mullet catch - Length - structure of this fish species population formed mainly by young small size fish, the biomass of latter estimated 1100 metric tons. Catch further than maximum sustainable yield, by higher exploitation rate, and gradual diminishing of harvest, represented the resources of this fish species suffering both by high fishing pressure and un - sustainable effort, which ultimately declined the fishery of this fish species. Carp catch and its resources in Anzali region become very low, it is necessary to enhance the stock by Sea-ranching programmes. The carp resources in Gorgan region enjoy better status, but catch practices do not compatible with rule and regulation in Gorgan and Gomeyshan area. The standing stock of Gorgan carp estimated nearly 6000 tons. The information concerning carp resources indicate the stock experiencing pressure and likely the catch will diminish in future. The total catal catch of carp calculated 1900 tons. In recent years the Caspian roach resources are increasing but the bulk of harvest fished illegally and by gill - nets. The total catch of the roach during 1998-1999 estimated 1700 tons. Considering the semi - artificial propagation of roach in Golestan province, if has been concluded the multiplication of this fish species also should be planned by fisheries authorities for Anzali region. It is also advisable catching of this fish species to be regulated soon and selective catch are proposed. The catch of pike - perch during the year of 1997 - 98 jumped to 95 tons, but 90% of catch formed by young fish or sub – standard length size. Almost, all the increment of catch attributed to the releasing of millions of seedlings in the Sea which the plan has been implemented by Iranian Fisheries. Increasing the numbers of released seedlings, with higher average weight Identification of most suitable site for unloading the fries could ensure better survival rate and contribute the enhancement of resources and produce good catch for this desirable fish species. The total catch of Bream hit 18 tons, but most of the catch comprised by young fish with sub - standard size. The present formation of fisheries population of bream are the result of seedling releasing! In the Sea by Iranian Fisheries, since the catch of bream are negligible despite releasing programmes of seedling in a decade which 14million individuals until now, one could conclude the programmes do not contributed effectively to stock rehabilitation. The Caspian Barbus (Barbus brachycephalus) are at the threshold 01 vanishing, at present a few numbers are caught, therefore B.capito appeared in catch composition. The catch of latter species in recent two years are increasing. Total catch during the year of 1998 - 99 estimated 34.5 tons, biomass calculated 93 tons. Caspian vimba are small size fish which beach seiner (mesh size in bosom 30 millimeters) could not capture them ideally, bulk of the catch caught in illegal manner by gill nets. The total catch estimated 154 tons which the present fishing procedures surpassed total allowable catch (136 tons). In recent years the catch of this fish species are increasing. "Shemaya' similar in size with Vimba are caught less by beach seiner, illegal catch are considerable, the total catch in 1998 - 99 estimated 86 tons. The level of harvesting of this fish species are increasing in recent years and its population size become significant relative to last years. The main part of catch concerning Aspius fish species occured in Guilan coastal area, high fishing pressure reduced the population size, including low discharge of water in rivers during spawning period, impact negatively to reproduction. Catch statistic in 1989 showed 128 tons of this fish species are caught but in 1998 - 99 it has been reduced to 6.8 tons. It has been suggested artificial spawning could prevent its fate as endangering species. Caspian salmon catch estimated 78 tons during 1998 - 99, salmon population in Caspian Sea are supported by releasing reared smolts, which in recent years nearly 500 thousands fingerlings released in suitable rivers. After banning the gil nets application in Southern Caspian Sea, the catch of salmon in beach seining are increasing. It is necessary the released smolts in rivers being protected for its safe approach to Caspian Sea. The total catch of herring fish species in 1998 - 99 were nearly 700 tons. The bulk of the catch occur In Guilan fishing area, elimination of gill - nets usage in Southern Caspian Sea contributed the increment of herrings catch in beach seining. The herring resources in Caspian Sea reduced relative to past decades. The catch during 1913 – 1916 ranged between 130 - 160 thousand tons, in Caspian Sea.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Without Abstract.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: This study aimed to assess the social, economic and fish farming in cages in the Southern Caspian Sea. The Caspian Sea is considered as one of the most important water resources of Iran, in which due to the appropriate weather conditions in the north of the country, has the potential for marine aquaculture. With the implementation of this plan would say that with respect to the proposed initial selection from Kheshtsar in Mazandaran province and Kiashahr in Guilan province with along coastline of about 250 km from the depth of 20 to 100 meters and an the area of about 2027km2 has the cage aquaculture talent. Of course, at the depths of greater than 100 M by using the world technology procedure, there is also the possibility of the establishment of marine cage aquaculture. Now, with the regards of the above potential in the Caspian Sea coastline, it is expected at least 200 cages fish sites farming in with the establishment of 40 cages per site and produce 160,000 tons with creating of 1,000 direct jobs and 2,000 indirect jobs and income 2000 billion gross annual average net profit of 40% could be 800 billion in which will produce of proteins needed part of the country, creating jobs, welfare, prosperity and economy in the region. With the implementation of such national project, it is needed to establish pilot farms to reach the goals: environmental assessment studies, risk assessment, aquatic selection and the use of appropriate cage structures according to ecological conditions of southern Caspian Sea.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: 360 funnel traps were prepared as 30 in one row. They were bitted and located in different depths in sampling sites. Two rows each composed of 30 traps were located by stone, linking rope and boat with 50 m distance in sampling stations. The results showed that the average of total length of caught crayfish was 106.26±12.89 mm and their mean weight was 38.79 ± 15.54 gr. The largest crayfish had 171 mm length and 216 g weight. Also mean of total CPUE was 9.72±4.49 individuals in the study period. The evaluation by Schnabel approach indicated that fluctuation range of freshwater crayfish biomass with more than 120mm length was 131-313 with an average of 212.59 ±30.23 kilograms per ha. In this study freshwater crayfish biomass with more than 120mm length was 247 × 10^3 kilograms. The Maximum Sustainable Yield (MSY) was estimated 83 × 10^3 kilograms. In this study ّFecundity and biometry of crayfish (Astacus leptodactylus) was investigated during 2012-2013. The results showed that the average of total length of caught crayfish was 106.26±12.89 mm and their mean weight was 38.79 ± 15.54 gr. The largest crayfish had 171 mm length and 216 g weight. Mean number of ovarian and pleopodal eggs were estimated at 286 ± 82 and 246.31 ± 80.41 eggs (with 95% confidence limits), respectively. In this research, male to female ratio was obtained 1.21:1. The time of male moulting at 16° C was started from April and was ended in the late May, when the water temperature reached to 18° C. The second moulting of males and the first moulting of females was performed simultaneously in 18° C water temperature at September. Reproduction of freshwater crayfish was started from November and continued to May of the next year. Harvesting period was from May to late November.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: In 1999 Mnemiopsis leidyi was introduced to the Caspian Sea from the Black Sea with ballast waters from the ships. The comprehensive study on probability of controlling Caspian Sea invasive Ctenophora planned after a remarkable of decreeing in Kilka fish catches stocks and fisheris community problems. This study focus on reproduction experiments of Beroe ovata as the best candidate for control of Mnemiopsis population size in the Caspian Sea that was preformed in Turkey and Iran during 2002-2003. At 2002, 87 specimens of B. ovata, 10-50 mm transferred to Caspian sea ecology research center from Marmareh sea where acclimated with Caspian sea water gradually. At 2003, experiments were performed near to Black sea (at Sinop) with freshly collected Beroe ovata, 40-65 mm size in three salinity level treatment, the Black sea water 18 , Mixed water 15 and Caspian water 12 . 130 individuals of Beroe ovata were brought from Sinop (Turkey) to Iran during 2003. A number of Beroe specimens were sent to Guilan province for reproduction studies and another part were sent to Mazandaran province for both reproduction and mesocosem studies. For control we had 1 Beroe, length 30 mm in the Black Sea water that was alive during of study in Iran. The Jars were examined each day for ova and larvae and they were collected and put into glass container of Caspian water for hatching and developing survey, some of them were left without any handling for larvae developing. Also in another experiment the eggs collected from jars were placed in the same three treatments for studying of growth and survival. The results were unsuccessful on propagation experiments at 2002 since the spawning and hatching rates were very low (20 ova) and, none of the larvae developed into adults in Caspian Sea water. The spawning was more in Marmareh sea water with 138 ova where only 7 larvae was hatched. Results showed that Beroe specimens is able to survive and reproduce in Caspian water but was not as well as Black Sea also the Beroe larvae growth rate is low in the Caspian Sea water. Maximum fecundity of Beroe individual was 2212 and 235 ovae in Caspian sea water in site Sinop and Iran respectively. Results showed 34-100% eggs in Caspian sea water were destroyed and did not develop. In Iran we obtained only one larvae with 5 mm length, other larvae were at different stages of development but most of them were 1.2 2 mm. The results of mesocosm survey showed most of ova and larvae have been obtained from the tanks where individuals B. ovata were with Mnemiopsis. Fecundity of Beroe in the control with Black Sea water were between 17 to 1879 with average of 828 ± 112 ova. The poor results of B. ovata reproduction obtained in this survey in Caspian sea may be due to transportation and acclimation stress and low salinity of Caspian Sea water.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: This study is attempted to compare the number of rings and circular scales that are formed during various ages on Liza saliens. Sampling was carried out monthly during 2012-2013 using beach sine fishing nets. 102 specimens of different sizes were collected and transferred to the laboratory in boxes containing ice. The age of fish was determined by the number of annual rings as well as, the number of rings in each annual area. The distance between rings in each annual area was also measured. The results showed that the maximum growth was demonstrated in the first and second years. In the first year of life, the scale radius was nearly 2823.3±366.5(µm) which decreased to 1223.9±236.0(µm). The result indicated that 48 percentage of growth scales occurred in the first year and this value is only 21.8% in the second year. The number of growth rings in the annual regions decreased with increase in age. The result demonstrated that the average number of rings was 95.5±17.6 in the first life year of the fish. If you take into account the number of growth ring through years in comparison with the number of days in a year, it is clear that one ring was nearly made in four days in the first life year and it gradually reached 7.5, 15.9, 21.9 and 31.7 in the second, fourth and sixth years of life, respectively. One ring was approximately made in each month at higher ages.

Description: Published

Description: Age and growth of Bigeye Kilka, Clupeonella grimmi, were studied in Iranian waters of the Caspian Sea from early May 2006 to April 2007. The sagitta otoliths were removed for each 5 mm length interval up to a total number of 262 fish. Fork length and weight ranged from 92.5 to 142.5 mm and 4.2 g to 23.4 g, respectively. The largest length-groups was observed from December to February and the lowest in April, which was coincided with spawning period and feeding during wintering, respectively. The overall sex ratio (male:female) was 0.33:1 which differed significantly from the expected ratio of 1:1. The length-weight regression was W= 0.0000744 FL3.14 for females and W=0.0000341FL3.16 for males, indicating the Caspian Bigeye grew isometrically for both sexes. Age determination based on otoliths readings showed that the population was composed of six- groups from 2 to 7 years old which observed a rapidly growth during the second year. In the age compositions, the four years old specimens with a mean fork length and weight 115.5±7.8 mm and 11.9 ± 2.8 g were the most abundant age group and accounted for 40.1%. The condition factor was 0.7-0.8 which varied in difference months and coincided to the gonad development. Age-at-length data were used to determine von Bertalanffy growth parameters for this population in both sexes, indicating that K value and L∞ of females was more than that of males. The results showed that C. grimmi is a rapidly-growing species in the southern parts of the Caspian Sea.

Description: Published

Description: The study is part of a research project on the southern shores of the Caspian Sea (Mazandaran watersKelarabad) was conducted in 2012. The aim of this study was to evaluate the effects of fish farming in cages on the distribution, abundance and biomass of macrobenthos organisms in the water at a depth of 20 meters Kelarabad. Sampling was monthly at three stations including 1(seating cage), 2 (control with a distance of 500 m) and 3 (50 meters after the cage) using a grab with 30 cm diameter. A total of 6 groups of benthic organisms, including 2 branches, 2classes, 4 families and 6 species were identified. Overall, 23442 specimens of large benthic organisms were counted, the lowest and highest frequency at stations 1 (23.4%) and 2 (46.8%), respectively. The results showed that the highest abundance at station 2 with an average of 646.00±1230.43 N/m2 and biomass with 0.526±1.00 g/m2 in station 3, in which can be due to the lack of cage fish farming activity and the presence of big species to depend Cerastoderma lamarki, respectively. The highest abundance and biomass was in autumn with mean 888.3±1371.58 N/m2 and 0.524±0.887 g/m2 and lowest was in winter with mean 143.33±138.22 N/m2 and 0.070±0.078 g/m2 . This could be related to activity fish cage culture and wintering season. The Streblospio gynobranchiata of polychaeta dominant benthic organisms with large population accounted 93.3%. This could be due to exotic species, high power compatibility and suitability related to environmental conditions. The conclusion is that the abundance and biomass of macrobenthos organisms in station 1 was less than other stations in which can be duo to concerned fish cage activity and its effects on organisms’ infauna. Therefore, it is suggested that any activity in the Caspian Sea offshore aquaculture should maintain environmental considerations and implementation of detailed environmental impact assessment (EIA) projects.

Description: Published

Description: Exploitation of bony fishes resources started on 12 October 2005 and finished on 9 April 2006 in 2005-2006. 142 beach seines caught about 14333.4 tons of bony fishes by 47101 hauling. The total catch was estimated 21844.7 tones (Includes illegal fishery). Kutum, mullets and common carp comprised more than 97 percent of total catch. Length classes 39-40, 31-32 and 40-41 cm predominated for kuttum, golden grey mullet and common carp, respectively. Age groups 3 to 5 year comprised 84.2, 74.8 and 83.7 percent for Kuttum, golden grey mullet and common carp, respectively and age group 4 year was dominant with 42.0, 35.9 and 43.0 percent, respectively. K value and L∞ calculated 0.26 (/year) and 58.3 cm for Kuttum and 0.15 (/year) and 61.5 cm for golden grey mullet, respectively. The total biomass and MSY estimated about 24733.7 and 8550.4 tones for kuttum and about 16948.0 and 4999.0 tones for golden grey mullet, respectively. Exploitation rate (E) calculated 0.71 and 0.70 for Kuttum and golden grey mullet, respectively. In 2006-2007, the exploitation of bony fishes resources started on 12 October 2006 and finished on 7 April 2007 in 2006-2007. 134 beach seines caught about 14120.0 tones of bony fishes by 48470 hauling. The total catch was estimated 23801.8 tones (Includes illegal fishery). Kutum, mullets and common carp comprised more than 98.5 percent of total catch. Length classes 39-40 and 38-39 cm predominated for kutum and common carp, respectively and length classes 27-28 and 29-30 cm predominated for golden grey mullet. Age groups 3 to 5 year comprised 80.2 and 71.8 percent for kutum and golden grey mullet, respectively and age groups 4 to 6 year comprised 71.8 percent for common carp. Age group 3, 4 and 5 year was dominant with 35.5, 32.1 and 27.1 percent for kutum, golden grey mullet and common carp respectively. K value and L∞ calculated 0.27 (/year) and 60.7 cm for Kutum, 0.2 (/year) and 58.4 cm for golden grey mullet and 0.19 (/year) and 66.7 cm for common carp, respectively. The total biomass and MSY estimated about 46654.9 and 14801.4 tones for Kutum, about 19549.0 and 5748.4 tones for golden grey mullet and about 10584.3 and 2186.0 tones for common carp, respectively. Exploitation rate (E) calculated 0.69, 0.53 and 0.52 for kuttum, golden grey mullet and common carp, respectively.

Description: Iranian Fisheries Science Research Institute

Description: Published