نشریه بهره برداری و پرورش آبزیان
سال دوازدهم شماره 3 (پاییز 1402)

The activity of cooperatives is one of the important activities of the fisheries sector and its knowledge performance and economic funds can be effective in deciding on investment in this sector as well as economic planning. The aim of this study was to determine the role of cooperatives in the optimal economic use of dual-purpose dams in aquaculture in Mazandaran province from 20 selected cooperatives in 2016-2017. To ensure the completeness of the questionnaire, before starting the main stages of the research, five units were randomly referenced and the questionnaire was reviewed and finalized with Cronbach's alpha coefficient. The results showed that the fishing industry of Mazandaran province is one of the productive activities and has an effective role in transforming the methods of exploiting provincial facilities. The comprehensive data analysis method presents the relative efficiency of each production point by calculating the ratio of the total weighted product to the total weighted input. According to the obtained average technical efficiency, it was found that most sealing cooperatives used inputs and facilities as efficiently as possible and according to the calculated average technical efficiency (above 83% on average), if these factors are used better, they can increase the technical efficiency of the units by 20.8%. In this regard, and based on the linear programming method provided for these units, it is possible to plan for the production and target values of each unit.

Oak acorn is widely used as animal feed due to its low price. Oak acorns (Quercus brantii) were processed by de-hulling, drying and milling. In acorn flour, the total phenolic compounds, non-tannin phenols and condensed tannins were 14.71, 0.35 and 6.60 g/100g on the basis of dry matter respectively. Five isonitrogenous and isoenergetic diets with different levels of acorn at 0 (control), 25, 50, 75 and 100 g/kg, were prepared. A total of 435 fish (average weight 0.3 g) were randomly distributed in 15 tanks with three replicates and fed for 10 weeks. Polynomial orthogonal contrast analysis revealed that there were no significant differences in terms of feed intake, feed conversion ratio, protein retention, carcass ash and survival rate between treatments (p>0.05). Dietary intake of acorn significantly affected the weight after four weeks, final weight after 10 weeks, total length, head depth, specific growth rate, condition factor, protein efficiency ratio, lipid retention and carcass lipid and moisture contents, which represented linear order polynomial (LOP) models, but crude protein content of carcass displayed a cubic order polynomial (COP) model, using optimal acorn flour levels of 25.00 – 64.28 g/kg. Acorn flour improved the protein level of carcass, but deteriorated the growth performance and carcass lipid and moisture levels. Therefore, even if the amount of de-hulled acorn flour in the diet is low (2.5 % of diet), it is not allowed to use it without further processing.

To investigate the effect of oral administration of Moringa leaf powder, 360 rainbow trout (35.5 ± 0.5 g) were randomly divided into 12 tanks. The fish were fed with Moringa leaf powder levels of 0(control), 1, 2.5 and 5% for eight weeks. After the challenge test with Aeromonas hydrophila bacteria, the activity of alanine transaminase and aspartate aminotransferase enzymes in the 2.5% treatment significantly decreased compared to the control treatment (P<0.05). The optimal amount of Moringa leaf powder inclusion in the diet for aspartate aminotransferase enzyme based on polynomial regression analysis was 1.97% and 3.33% respectively for the periods before and after the challenge with bacteria. There was no significant change in the amount of alkaline phosphatase enzyme, the number of red blood cells, hemoglobin and hematocrit between all treatments compared to the control treatment in both periods before and after the challenge with bacteria (P<0.05). The amount of glucose showed a significant decrease in all treatments, especially in the 2.5% treatment compared to the control treatment in both stages (P<0.05). Regression analysis showed the optimal value of Moringa for this factor, 3.40% and 2.77%, respectively, before and after the challenge with bacteria. According to the results, moringa leaf powder at 2.5% can help reduce stress and possibly improve the general health of this fish. The appropriate dose was obtained from 1.97% to 3.4% based on polynomial regression model for serum biochemical parameters such as glucose and aspartate aminotransferase enzyme.

The aim of this study was investigating the antimicrobial activity of microalgae Sandosmus and Spirulina cultivated in the BG-11 culture medium and the effluent of the desalination facility of Bandar Turkmen unit, Golestan province, in inhibiting the growth of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Algae were extracted by water-alcohol method in proportion (500cc of alcohol and 50cc of distilled water) and determination of minimum inhibitory concentration (MIC) was checked by broth micro dilution method (96 house plates), and were compared to their usual environment with the amount of antibacterial activity grown in water. The results of two mentioned bacteria in the presence of different concentrations of aqueous-ethanolic extract within 24 hours showed that in the extract of the genus Sandosmus and Spirulina grown in BG-11 culture medium and 50 and 100% effluent dilutions, there was no antibacterial effect against Escherichia coli and Staphylococcus aureus bacteria during (24 hours). Sandosmus extract grown in BG-11 with 25 and 50 concentrations had higher E. coli bacteria volume than spirulina in the early hours. As the concentration increases, the volume of bacteria decreases in the early hours. Spirulina extract grown in BG-11 showed high resistance to Staphylococcus bacteria in the early hours compared to Sendesmus. Sendesmus extract grown in 50% wastewater compared to Spirulina had the highest amount of E. coli bacteria in the final hours, so it showed a high resistance to E. coli compared to spirulina. Also, in the extract of Sandosmus grown in 50% wastewater at concentrations of 25, 100 and 200 mg/ml in the final hours, the volume of Staphylococcus bacteria was higher than the concentration of 50 mg/ml, and in spirulina there was a constant trend in the final hours. In both extracts grown in 100% wastewater against E. coli bacteria in all concentrations within 4 hours, they showed the highest amount of bacteria. Therefore, in all concentrations of both extracts, they showed an increase in the volume of Staphylococcus bacteria over time (2-4 hours). Therefore, spirulina grown in 100% wastewater had a stable trend in the last hours compared to Sandosmus and showed more resistance to staphylococcus.

The purpose of this study to develop a framework for investigating the catch trend and estimation of optimized catch limit of the P. homarus stock by collecting catch data in the northern waters of the Oman Sea. In this research, the landing catch data of the northern waters of the Oman Sea (Sistan and Baluchistan province) for more than twenty years (based on tons) have been collected from the Iranian Fisheries Organization (1997-2019). The average catch for this study period is 33±6 tons with a 95% confidence interval of 27-39 tons, and the amount of catch increased during the study period (R = 0.37). The average (95% confidence interval) for the intrinsic growth rate (r), maximum sustainable yield (MSY), biomass of maximum sustainable yield (BMSY), and carrying capacity (K) were obtained 0.56 (0.4-0.78) annually, 140 (120 – 170) tons, 156 (95 - 255) tons, 313 (192-510) per year, respectively. Based on the trends of B/BMSY and F/FMSY ratios, it can be said that the increase in fishing mortality and the decrease in available biomass started in 2014 and continues. This research shows that the annual harvest of this species has reached its maximum amount and measures should be taken to reduce the amount of catch and fishing effort.

The aim of this study was to determine the catch composition differences (morning and evening) during the fishing season of ribbon fish (Trichiurus Lepturus Linnaeus 1785) in the winter of 2020 from the Hormozgan province. The fishing operation was carried out by a mid-water trawler for a week from 6 am. to 6 pm. The average duration of each hauling was 4 hours and the depth of hauling was recorded between 58-68 meters. The ship was equipped with a trawl net with a 41-m head rope and a 75 mm stretched mesh size in the codend. Results of 21 hauling, 23 fish species belonging to 17 families were identified. The frequency of target fish (ribbon fish) was calculated 12719 fishes, with total catch of 21423 kg and CPUE of 1020.14 kg/hauling. The total by-catch was recorded 1828.28 kg, and CPUE of 87.10 kg/hauling. There were no significant differences between total catch of target fish, total by-catch in the morning and evening time, also CPUE and CPUA of target fish(p>0.05). The highest participation rates of fishes were croakers (4.85%), wolf-herring (3.03%), king soldier bream (2.65%), four-finger threadfin (2.59%), queen fish (2.50%), barracuda (2.29%), lizardfish (2.22%), pick-conger (2.01%), king mackerel (1.93%) and trevally (1.85%) respectively.

The process of catching fishing gear that goes out of control is called ghost fishing. Abandoned, lost or discarded fishing gears (ALDFG) can cause adverse economic and environmental effects. Passive fishing gears, such as cages, produce more severe effects after being released into the water. Gargoors are one of the types of cages, which every year a large number of them are left in the sea in the Persian Gulf and the Oman Sea, for various reasons. In recent years, a new generation of gargoors with a rebar body covered with net are used in the waters of Bushehr. In this study, which was conducted from November to July 1400 in the waters of Bushehr, totally, in 310 cruises in 30 coordinates, by 9 vessels, 90 gargoors made of rebar were surveyed. All of them were baited with wolf herring and catfish. 24 species from 12 families were identified. The most observed species was Orange-spotted grouper (Epinephelus coioides). The results showed that all the gargoors made of rebar, if they are not lost, return to the land after the end of fishing. The main reasons for getting lost were theft, trawling, and bottom gillnets, respectively. Also, to confirm the sampling results, 40 questionnaires were distributed among the fishermen. According to the results, rebar gargoors are preferred over wire gargoors in terms of life, strength, economic efficiency and lower amount of ALDFG. It is recommended that researchers combine their knowledge with the experiences of fishermen to design gargoors with fewer disadvantages while maintaining the merits of different gargoor models, especially from the economic and environmental point of view.

The effects of formic acid on growth performance, blood indices, and digestive enzyme activities of common carp (Cyprinus carpio) were examined over 60 days. The common carp (mean weight of 10±0.11g) were randomly allocated to four experimental treatments with three replications (25 pieces in each replication) including control treatment (no propionic acid) and three treatments which received formic acid (0.5, 1, 1.5 gr/ kilogram diet). The results indicated that growth parameters (final weight, weight gain, specific growth rate, condition factor, and FCR) were significantly different between the control and experimental treatments. The final weight, weight gain, specific growth rate, and condition factor in the propionic acid treatments had a significant increase compared to the control group (P < 0.05). The results of study showed that no significant difference in blood parameters were observed between treatments (P > 0.05). The highest lipase activity (21.73± 1.18 U/L) was observed in 1 g/kg propionic acid group (P < 0.05). Moreover, the highest protease (303.15± 4.16 U/L) and amylase activities (650.26± 10.05 U/L) were recorded in 1.5 g/kg propionic acid group (P < 0.05). According to obtained results, inclusion of propionic acid in common carp diet had a positive effect on the improvement of growth performance and digestive enzyme activities; therefore, a diet containing 1.5 g/kg propionic aid proposed to enhance growth performance and digestive enzyme activity of common carp.

Improving the immune system and growth of fish with seaweed instead of antibiotics can be a good idea for aquaculture. For this purpose, twenty four hundred red tilapia fish after adaptation to laboratory conditions were divided into four treatments with three replicates, and then fed diets contained control (without sargassum extract), 1, 2, and 3% of Sargassum ilisifulium extract for 8 weeks. The results showed that 2% Sargassum extract causes a significant increase in growth indices (specific growth factor, weight gain) and a significant decrease in food conversion ratio (P<0.05). All fish fed with different levels of Sargassum extract had more protein and less fat contents in the body compared to the control group (P<0.05). The amount of total protein, immunoglobulin, and lysozyme activity of the mucus in the fish fed with 2% Sargarsum extract was significantly higher than other experimental groups. (P<0.05). As a result, it is suggested to use 2% of dietary Sargassum extract to improve immunity and growth performance of red tilapia fish.

The lake’s trophic state can well represent human disturbances on these ecosystems. The present study was conducted seasonally to investigate the trophy status of Bostan Dam Lake (Golestan Province) from spring 2019 to summer 2020 in five study stations. A number of physicochemical parameters were determined such as pH, electrical conductivity, temperature, dissolved oxygen concentration, Secchi disk depth, salinity, dissolved solids, total hardness and turbidity. While nitrate, phosphate, total nitrogen, total phosphorus, ammonia, total alkalinity and chlorophyll evaluated using standard method. Carlson's index, the amount of nutrition in different parts of the lake estimated based on total phosphuros, chlorophyll and transparency. The result of Carlson's index showed different values between 52.44 to 60.46 and eutrophic condition in lake. The present research can provide a decision support system in the future to achieve optimal monitoring and exploitation and water quality management of the reservoir behind the Bostan Dam.

Carrageenan is a marine biopolymer that can be extracted from cell wall of some red carrageenophyte. In this present, response surface methodology was used to investigate the procedure of carrageenan melting point and gelling temperature from algae of Hypnea flagelliformis. Independent variables, alkalinity concentration (0/25-2%), extraction temperature (70-90°C) and extraction time (60-240 minutes) were applied in five levels. all Base on the result, effects of all independent variables on melting point were significant (p<0.05), whereas alkalinity concentration had significant effect on gelling temperature (p>0.05). Polynomial models developed for the melting point and gelling temperature indicated that optimum conditions. Optimum data for independent variables were alkalinity concentration 1.54%, temperature 85 °C and time 203 minutes.Confirmatory test was earned as follows melting point 63.8 ±0.91 °C and gelling temperature 37.29 ±0 /62 °C. The experimental data and model forecasting were similar (P> 0.05).

Hydrazones are an important class of bioactive drugs that have attracted much attention .One of the domains in this category of compounds is the synthesis of new hydrazone derivatives from NSAIDs, which are supposed to be more effective than the previous synthesized derivatives in terms of effect strength and severity of the complications. Many compounds of different chemical derivatives are designed and synthesized to treat various diseases, among which hydrazones are included, and their anti-cancer effects have been reported so far .The aim of this study was to investigate the hepatotoxicity profile of 4-chlorobenzolidin-hydrazine-naproxen derivatives and compare it with the main drug, naproxen. 120 fish specimens of Trichogaster trichopterus with average weight of 2.4±1 gr in 8 treatments were divided into control groups, control1 (intact), control2 (DMSO) and treatment groups receiving 10, 20, 30 mg/kg of naproxen and 10, 20, 30 mg/kg of hydrazine naproxen derivatives. These concentrations were selected according to previous works and related articles. After anesthetizing the fishes, liver tissue and liver enzymes were studied in treatment groups and the groups receiving the drug compared with control groups. The statistical results of the level of liver enzymes between control groups and treatments showed a significant difference (P<0/05). Histopathological examination of the liver tissue of the treatments indicated that the liver tissue had undergone a major change in the high doses of both drugs. The results showed that naproxen and hydrazine naproxen derivatives affect liver tissue and liver enzymes by increasing doses and increased sinusoidal spacing, and adipose vacuoles in liver.

The present research was done with the aim of encapsulation of fish oil with a ratio of 3:1 (oil: coating) with coatings of maltodextrin, sodium caseinate, whey protein concentrate and modified starch with different ratios by freeze dryer and in order to achieve the maximum encapsulation efficiency was optimized using a mixture design. Optimizing the concentration of different walls for microencapsulation using numerical and graphical optimization revealed that the optimal wall composition contains maltodextrin (15.16%), sodium caseinate (20%), whey protein concentrate (20%) and modified starch (19.84 %) with the encapsulation efficiency was 89.3 %.The results showed that according to the difference in the wall compositions and their ratios, the particle size, poly dispersity index (PDI), and encapsulation efficiency had different values. So that the size of the particles varied from 0.34 μm to 1.3 μm, and the PDI varied from 0.1 to 0.92. Evaluation of oxidative stability in optimal microcapsule powder and free fish oil stored at 0 and 32% humidity during 21 days of storage showed that encapsulated oil at zero humidity had higher oxidative stability during the storage period. In addition, the increase in humidity in the storage environment of microcapsules increased the intensity of oxidation in the treatments stored in 32% humidity. Therefore, it can be concluded that the use of microencapsulation technique is a practical and effective method to increase the oxidative stability of fish oil for use in the food and drug industry.