cage culture

In the present study, the nutritional value of Asian seabass grown in cages was evaluated based on the measurement of proximate compounds and minerals according to AOAC standard method and UV-Vis spectroscopy, respectively, and protein quality indicators were evaluated based on the amino acid analysis using acid hydrolysis and chromatography. According to the results, the levels of moisture, protein, fat, and ash were determined as 77.78, 17.36, 3.21 and 1.56%, respectively, and the energy content was 98.33 kcal/100 g. The results of minerals indicated a high content of sodium and potassium at 371.41±50.98 and 230.26±40.23 mg/100 g and manganese had the lowest level at 0.29±0.11 mg/kg. A total of 18 amino acids were identified, of which 9 were identified as essential amino acids. Glutamic, aspartic, and lysine amino acids were dominant in this profile. The values ​​of protein quality indices including essential amino acids index, biological value, nutritional index, and protein efficiency ratio in this species were obtained as 58.955, 52.53, 10.23, and 2.90, respectively.

Breeding and production of fish in sea cages is one of the most common methods of commercial production of aquatic animals in the world. It is possible to develop aquaculture in the Caspian Sea by fully respecting the biotic, abiotic, social, and economic conditions, as well as the environment, with regard to sustainable development. Breeding fish in cages is very important from an economic point of view, and determining the challenges and obstacles before investment in order to reduce the investment risk plays a fundamental role in it. The purpose of this article is to investigate the economic challenges of cage culture development on the southern shores of the Caspian Sea using a combination of SWOT and FAHP analysis and then determine strategic priorities based on the Quantitative Strategy Planning Matrix (QSPM). In order to meet the challenges and also formulate strategies, the SWOT analytical model was used, and the opinions of 30 fisheries experts were obtained through face-to-face interviews and completing questionnaires in 2020-2021. According to the final score obtained, opportunity factors got 2.89 points, and threat factors got 3.54 points. As a result, the threat points prevail over the opportunities, and it shows that the current situation of this activity requires strategies in the field of adopting solutions to reduce threats. According to the total scores of the obtained matrix, the score of external factors indicates the need to formulate a defensive strategy in order to reduce the minimum risk of investment. According to the SWOT analysis, the strategies with the highest score are "development of standards and criteria and locating suitable areas for cage fish breeding sites," "allocating low interest loans and encouraging investors in order to facilitate investment," and "sustainable development in order to prevent Changing the use of valuable agricultural land" and "attention to export, introduction, and cultivation of species with global marketability" were presented in order to solve the existing challenges and suggestions to make the fish farming industry in the Iranian regions of the Caspian Sea.

Biofouling in marine aquaculture is a specific problem where both the target culture species and/or infrastructure are exposed to a diverse array of fouling organisms, with significant production impacts. In shellfish aquaculture the key impact is the direct fouling of stock causing physical damage, mechanical interference, biological competition and environmental modification, while infrastructure is also impacted. In contrast, the key impact in finfish aquaculture is the fouling of infrastructure which restricts water exchange, increases disease risk and causes deformation of cages and structures. Consequently, the economic costs associated with biofouling control are substantial. Conservative estimates are consistently between 5–10% of production costs (equivalent to US$ 1.5 to 3 billion yr-1), illustrating the need for effective mitigation methods and technologies. The control of biofouling in aquaculture is achieved through the avoidance of natural recruitment, physical removal and the use of antifoulants. However, the continued rise and expansion of the aquaculture industry and the increasingly stringent legislation for biocides in food production necessitates the development of innovative antifouling strategies. These must meet environmental, societal, and economic benchmarks while effectively preventing the settlement and growth of resilient multi-species consortia of biofouling organisms.

The aim of the present study is to investigate the growth performance and sexual maturation process of female rainbow trout reared in a cage in the Caspian Sea (Mazandaran- Nowshahr). Rainbow trout with an average weight of 122± 5 g were stocked into a cage located in Caspian Sea. Fish were fed daily and random sampling was done monthly (January 2015) to May 2016. Weight and length of thirty fish were measured; their gonad and liver were weighted; total length, total weight, liver and gonad weight, condition factor, GSI and HSI and oocyte diameter were calculated; their blood samples were collected and the levels of 17 beta estradiol, testosterone, progesterone and the vitellogenin were measured; also gonad tissue samples were prepared and examined using a light microscope. The results showed optimal somatic and gonadal growth of fish caged in the Caspian Sea. Sex hormones and vitellogenin levels increased significantly (P<0.01) during the study period. The levels of 17 beta estradiol, testosterone and progesterone in January were 0.56± 0.05 ngml-1, 0.50± 0.05 ngml-1and 0.14± 0.01 ngml-1 respectively and reach to 1.63± 0.13 ngml-1, 0.80± 0.01 ngml-1 and 0.28± 0.03 ngml-1 in May, respectively. Vitellogenin levels increased from 382.40± 55.26 ngml-1 in January to 651.40± 86.34 ngml-1 in May. The gonads developed to stage 4 and the oocyte diameter increased significantly (P<0.01) during the study period. The findings of present study show that female rainbow trout are able to have appropriate somatic growth in the brackish water of the Caspian Sea like fresh water, and the natural process of sexual maturation won’t be disturbed.

This study was designed to determine the effect of rainbow trout culture in floating cage on the distribution and structure of Phytoplankton community in the Abbas Abad area, southern basin of the Caspian Sea. For this purpose, water and phytoplankton samples were collected by a distances of 5, 50, 100 and 1000 m from the cage culture during December 2014 (pre cage), March and April (production period) and August 2015 (post cage). The results of physicochemical factors of water showed that most of the measured parameters had significant differences only among different sampling periods (P<0.05). In this study, 42 taxa of phytoplankton belonging to five phyla (with the dominance of Bacillariophyta) were identified. The results showed that the abundance of most dominant phytoplankton samples had a significant difference during different periods (P<0.05), but this significant difference between different stations was observed for few species studied only. Also, the results of determining the effect of environmental factors using CCA test on the Bacillariophyta abundance showed a minor impact and a positive correlation with turbidity and total nitrogen, While the effect of temperature and ammonium on its abundance was negative. It seems that the rainbow trout cage culture in the Abbas Abad region had a minor impact on water quality factors and nutrients concentration probably due to short duration of cage culture activity and high velocity currents, but no remarkable effect on phytoplankton structure in the vicinity of fish cages, so that the observed changes were more associated with seasonal fluctuant.

This study was conducted to investigate the possible effects of cages culture Asian sea bass fish (Lates calcarifer) on the population structure of macrobenthos in the Rigo area of Qeshm Island in Hormozgan province during a breeding period in 1397 were investigated. The average abundance of macrobenthos at the location of the cages culture and the refrences site in this study was equal to (52765 ± 19154 in m2) and (50642 ± 21002 in m2), respectively.The results showed that at the time of the study among the identified the genus of Ammonia sp. With a relative abundance of 73.41 percent at the location of the cages compared to the control station and Archasterope sp., Spirolochulina sp. and Nephtys sp. with a relative abundance of 63.9%, 49.1% and 12.6%, respectively, were more dominant in the control station compared to the location of the cages.The loading rate of organic matter in the bed of the cages was significantly affected by fish farming activities and in some times showed a significant difference with the control station (P<0.05). In general, at the time of the study, activities related to fish farming in cages had no effect on the population structure of macrobenthos in the study area.

The present study aimed to identify, introduce and compare pseudoparasites in wild fish (Rutilus kutum and Mugilidae) and cage culture rainbow trout (Oncorhynchus mykiss) in the southern coast of the Caspian Sea. Wild fish specimens were collected from four stations in Anzali, Kiashahr, Chalus, Mahmoudabad and rainbow trout in three cages of Kiashahr, Abbas‌‌‌‌abad and Si-Sangan. After transferring the specimens to the laboratory, they were bioassayed and parasitological examination was performed on all internal and external organs. Free-living nematodes, pine pollen, pollen grain, protozoa, fungal spores, plant seeds, and filaments were isolated from fish as pseudoparasites. The highest percentage of pseudoparasites belonged to Pine pollen and was found in almost all fish organs. Free-living nematodes were isolated from the stomach, intestine, gills and Pollen grain from the liver, spleen, and kidneys of fish. Pseudoparasites are widespread in addition to they may be transmitted by food or randomly to fish. Pseudoparasites do not cause infection and disease in their host. Investigating and understanding them because of their importance in the parasitology can be useful for parasitologists and fish farmers to avoid the futile consumption of pharmaceuticals.

This study was carried out to determine the effect of raibow trout cage culture on the abiotic factors of water in the Abbas Abad area, southern basin of the Caspian Sea. For this purpose, water samples were collected at distances of 5, 50, 100 and 1000 m from the cage culture during December 2014 to August 2015. Based on the results, it was shown that the mean value of water temperature for surface layer varied between 12.2 and 30.16 °C from December to August. The highest and lowest mean value of salinity obtained in August (11.26 g/l) and April (10.66 g/l) respectively. The range of pH value changes (8.36-8.83) was as small as the rate of electro conductivity variations (18.11-19.07 µs/cm). The highest concentration of dissolved oxygen was observed in December at 1000 m station (9.23 mg/l) and the lowest was seen in April at 5 m station (7.27 mg/l). Also the mean values of Total Dissolved Solids, Turbidity, Nitrite, Nitrate, ammonium, Total Nitrogen, Phosphate and Total Phosphorus was obtained 9.59 (g/l), 5.55 (NTU), 3.67, 133.45, 92.6, 929.72, 21.63, 37.73 (µg/l) respectively. The results of abiotic factors of water showed that most of the measured parameters had significant differences only among different sampling periods (p<0.05) whilst, for some factors such as dissolved oxygen, ion ammonium and phosphate, there were significant differences between different stations (The effect of distance from the cage) at each sampling period as well as (p<0.05). It seems that the cage culture of rainbow trout in the Abbas Abad area had only a minor impact on measured factors probably due to low stocking density, short-term of fish farm and high current velocity.

One of the necessities for aquaculture development is approaching to cultivation of new species. Among new species, marine fishes have high importance due to advantages like high growth rate and viability for cage culture. Cobia (Rachycentrom conadum) is one of the endemic marine fish in southern Iran. Cobia has a high potential for aquaculture due to its characteristics such as rapid growth, lower puberty age, delicious taste and high market value. This species is cultivating in different countries around the world, specially southeast Asia since the 90s, but there is no significant experience on commercial rearing of this valuable species in Iran so far. There are considerable stocks of cobia in southern Iran, specially in the Persian Gulf which eases access to its eggs and fries. Development in aquaculture of cobia depends on access to sufficient information about propagation and rearing of this valuable species. Therefore, the present paper evaluated practical manual for propagation and rearing of cobia.

The use of chemicals in aquaculture to treat parasitic diseases of cultured fish is widespread. In cage culture of marine fish, ornamental fish is used as a biological controller of exotic parasites however, the existing reports about the impossibility of mass production of cleaner fish by artificial reproduction and also their sensitivity to some farmed fish parasites and diseases, has caused to shift to use of cleaner shrimps that can be easily reproduced and mass-produced under artificial conditions and they do not have a common disease with farmed fish. The effect of cleaner shrimp in reducing parasites in farmed fish remains undiscovered. The use of biological control against parasites in aquaculture may reduce the use of chemical interventions. Therefore, investigating the issue of ornamental shrimp (cleaner) culture, due to marine fish culture development, especially in cage culture system is necessary. According to this, research on selection of the appropriate species and providing broodstocks as a priority is suggested to research centers, academic and executive. In addition to provide required shrimp for the marine fish aquaculture sector, this activity should be introduced as a new job in the ornamental aquatics and aquarium market by promoting biotechnology to the people.

This project carried out between Augest in 2017 and October in 2018 in the Golestan Dam. A questionnaire was prepared from the household of 4 villages: Gharajeh, Arab Sorang, Agh Abad and Sarjeh Kor. Statistical Methods of Krumbachchr('39')s alpha were used to analyze the questionnaires. The most commonly used scale in social research is the Likert comparison were used to test the validity of the questions. Topsis method was used to investigate the power of effective factors and prioritize it. The Logit model was used to identify descriptive variables and their relationship with event occurrence and eventually an estimate of the probability of occurrence of an event for a particular person. Chi-square test was used to study the effect of gender and age on social and economic parameters. The results of model estimation using the Logit method showed that age, gender and interval variables at each level of 10%, employment at the level of 5%, and migration at the level of one percent, affect the willingness of the people. The results of weighting the criteria using the entropy method indicate that the criteria for improving the economic situation, increasing income in rural communities of the region, employment related to aquaculture, improving the lives of villagers, and increasing aquaculture employment are one of the most important social impacts of this activity. The results of this study showed that fish farming in cages of Golestan Dam can directly affect employment creation, improve economic situation in the region, tourism and reduce rural migration to cities. On the other hand, protein production can have a significant impact on the per capita consumption and nutritional health of residents.

Microbial contaminants entering the aquatic environments can endanger the health of swimmers, sailors, tourists, fishermen, fish cage culture personnel, as well as the production and quality of aquatic food. In the present study, some bacterial contamination characteristics of Hassanlu Reservoir Lake were investigated for fish cage culture monthly at different sites (stations 1, 2 and 3: the south shore of the lake / the villages adjacent to Hasanlu; station 4: the dam’s exit; stations 5, 6 and 7: the north shore of the lake / the Mahabad-Urmia road; station 8: the middle of the lake where cage culture of rainbow trout were installed; and station 9: the mouth of the Godar River) during April 2017 to March 2018. The results showed an increase in total and fecal coliforms as well as E. coli contamination in seasons with higher temperature. The amount of microbial load in the upstream station – station 9- (river inlets) and also the station 1 (rural area) were greater than the middle and crown stations of the Hasanlu reservoir lake. The microbial indices of Hassanlou lake indicated that if other biological and non-biological factors are in the range of bio-economic life of cultured fish, it would be suitable for fisheries exploitation such as catching and culturing of narrow-clawed crayfish (Astacus leptodactylus), however, caution should be exercised about culturing of edible oysters and aquatic life and cage culture. Therefore, it is suggested that management and monitoring programs be adopted with the cooperation of all relevant agencies to prevent or reduce the entry of various pollutants into these water bodies so that in the future the potential of Hasanlu Lake to develop other aquaculture production, and to reduce fishing pressure in water bodies as well as to help sustainable production and job creation in the region.

Microplastics are particles smaller than 5 mm that can enter to the environment through primary or secondary sources. These particles can be vector for various chemical compounds in the environment, such as pesticides and pollutants. The absorption of these particles into the body of organisms, especially aquatic organisms, causes changes in the activity of their enzymes, especially antioxidant enzymes. The aim of our study was to investigate the effect of polystyrene microplastic and chlorpyrifos pesticide alone and in combination on the superoxide dismutase (SOD) activity tissues of rainbow trout (Oncorhynchus mykiss). Fish were exposed to two concentrations of chlorpyrifos (2 μg / L, 6 μg / L), polystyrene microplastic (30 μg / L, 300 μg / L), and their combination. Then the superoxide dismutase activity was examined in the liver, kidney and muscle tissues of fish. Analysis of the results with significance level of Pvalue μgL-1 MPs pesticide and in combination of 30 μg / L microplastic  and 2 μgL-1CPFpesticide enzyme activity was decreased. In general, it was concluded that microplastics in liver and kidney decrease the bioavailability of chlorpyrifos pesticide and in muscle increases the toxicity and bioavailability of pesticides.

This study was designed to determine the sediment structure, Total Organic Matter (TOM) and facultative anaerobic bacteria communities of sediment affected by cage culture of rainbow trout in the coastal waters of Abbas Abad area (southern basin of the Caspian Sea). For this purpose, sediment samples were collected at distance of 5, 50, 100 and 1000 m from the cages in December 2014 (before the culture period), March and April (production period) and August 2015 (after the culture period). Determination of sediment grading showed that its structure was composed of silt-clay (91.7%) and very fine sand (6.44%) and the sediment structure was not affected by the cage culture. The Total Organic Matter was significantly different only between the sampling periods (P<0.05) so that the highest amount of Total Organic Matter (TOM) was observed during the production period whereas, it was not affected by the distance from the cages (P<0.05). It seems that the rainbow trout cage culture in the Abbas Abad region no remarkable effect on the factors studied in the vicinity of small scale fish cages due to the short duration of cage culture and strong water currents, so that observed changes were more associated with seasonal fluctuant.

This study carried out to investigate the fluctuation of benthic population in cages of rearing trout (Oncorhynchus mykiss, Walbaum, 1792) in depths of 30-25m of southern part of Caspian Sea at Nashtaroud region of Mazandaran province, This study was performed 150 days with measuring and evaluating physico-chmical factors of water during 5 phases up to the end of rearing period .Samples collected by Ekman Grab was 3 replicates in and out of cages, monthly. In order to investigate population of benthic, some indices such as Shanon-wiver,Simpson and Margalof are used to determine diversity dominance and enriching of species. Totally, 200 specimen of invertebrates (g/m2) belonging to 3 families Bivalvia Molluscas, polychaeta worms and Crustacea collected. The maximum and minimum biomass belongs to Abra ovata 49.2 gm-2 and species like Nereis diversicolor, Balanus improvises and Mytilaster lineatus 1gm-2 respectively. The results of study on organic material showed significant differences in the stations, so that highest was seen in west of cages and the lowest seen inside the cages (P<0.05). There is significant correlation between density and biomass of benthic and percent of mud in the bottom (P<0.05). The results showed positive correlation between Shannon diversity index and biomass of benthic (p=0.001; r= 0.684). Results showed that although after the introduction of salmon cage rearing larvae statistically significant difference was observed in the diversity and density benthoses (P<0.05),but the changes in the diversity of macrobenthose have been very little and partial in the established rearing cages. According to ecological of Classification was done educational platforms studied were placed in stressful and polluted.

This study has been in order to investigate the effects of cage culture in the south of the Caspian Sea, Kelarabad. Sampling was in three direction of cages, East, West and South (the coast of Caspian Sea). For this purpose, four stations on each side of the cages was considered in terms of distance, the shadow (5 meters) to a distance of 1000 meters cages (control). Grain size analysis shows, the silt - clay (particles smaller than 63 microns) with mean (25/44- 98/4) and the average percentage of total organic matter (TOM) in deposits with mean (1/74-7/21). As the results show in all of the period of fine-grained particles was silt particles (mm ˂0/063), The highest the percentage of total organic matter at  station 3, and the highest percentage of organic matter showed in Station 3 (100 meter) to early (January), where it can because of sea currents (silicon and anti-silicon) from West to East. The results showed that the abundance of benthic invertebrate in station 4 (control) was higher than in the shadow of cages, which can be due to the cage culture and water flow. The lowest of the biomass was in the shadow of the cages and the highest was in station 3 (100 meters), in which can be due to presence of big species and high resistance to unstable conditions governing the location of marine cages to depend Cerastoderma lamarcki. According to the water flow that move and carry more organic matter from where the cages to this point has led to an increase in biomass. Shannon index range was determined between 0/29- 0/92 that reflects the diversity is low of the study area. Measurement of biological indicators such as diversity, abundance, indicator species, slight differences between the station bottom of cage and the station away from the cage, showed that some of these differences may be caused by fish farming in cages.

Vibrio harveyi is one of the opportunistic marine environment bacteria that are considered as one of the main causes of Asian seabass vibriosis diseases in many marine cage farms in the world. The aims of this study were isolation and identification of these bacteria in cultured Asian seabass in farms, located southern provinces of IRAN (Khuzestan, Bushehr and Hormozgan). In this study, a total number of 110 Asian seabass (80, with clinical sings of disease and 30, apparently healthy fish) with different body weight ranging 50-700g were sampled. Isolation was done from internal organs (kidney, heart, spleen and liver) in common method of bacterial isolation and isolates subjected to phenotypic and molecular characteristics using duplex PCR amplification of the 16SrDNA & vhh genes respectively genus & species-specific gene. The results of PCR showed that of the 95 phenotypically identified isolates, only 65 isolates belong to the genus vibrio and 46 (70.76%) of them were identified as Vibrio harveyi. These results indicate a high present of Vibrio harveyi in cultured Asian seabass in studied farms. Results of the biochemical characteristics of the isolates confirmed with PCR, showed isolates have different reaction in several biochemical tests. Accordingly, the duplex PCR method presented in this study was introduce as an accurate and rapid method for diagnosis of V. harveyi.

According to the climatic, ecological and hydrological conditions in the Caspian Sea and according to the Caspian Sea is an enclosed inland body of water and habitats for many valuable aquatic species and endangered sturgeons, it is necessary that comprehensive studies are conducted before any development on fish culture in the sea. This project was financially supported by the Fisheries Organization of Guilan Province and was conducted in the International Sturgeon Research Institute in order to investigate abiotic factors for sturgeon cage culture in Jafroud region of Anzali Port (depth of 50 m) for one year. Physico-chemical factors were investigated monthly. The investigations were carried out in four stations in cage and one station outside the cage (20 m in the opposite direction of water flow in the west). The abiotic conditions for fish cage culture including physico-chemical factors (temperature, dissolved oxygen concentration, pH, salinity as well as nitrite, nitrate, orthophosphate, electric conductivity and total Suspended Solids (TSS) were measured monthly. physico-chemical factors in rearing cage significantly did not affected (p<0.05) growth rate of Huso huso. Also results obtained from this study revealed that there were no significant differences between parameters inside and outside of the cage (p<0.05). However, significant effects of variations in TSS, Total Organic Matter (TOM) and grain sediments factors levels were observed in inside and outside of the cage (p<0.01).The results of abiotic factors found around the stations are in the range of the allowable concentrations of theses parameters for culture. Considering to the environmental findings, the results of this study provides the useful information for fish culture to manage well based on the water quality and hydrological foreseen. The results from this study can enable managers to obtain necessary data to evaluate the rearing capacity of fish in marine cage to issue the permits for sturgeon culturists.