Sustainable Aquaculture and Health Management Journal
Volume:6 Issue: 1, Winter and Spring 2020

The COVID-19 pandemic is now spreading throughout the world affecting the agricultural activities including fish and shrimp culture sectors. Most of the shrimp producing countries particularly in South-east Asia have been affected due to the lockdown, quarantine roles and regulations ordered by the countries, which was assigned to reduce and control the COVID-19 pandemic spreading in the globe. The current establishment of the restriction and quarantine roles has significantly reduced the domestic and international transportations that can seriously affect the shrimp supply chain in the world. Further, the labor shortage, delay in shrimp harvesting and insufficient supply for the processing of shrimp in the plants are other impacts due to coronavirus outbreaks. The impacts of COVID-19 disease on world shrimp aquaculture can be numerous and is varied depending on the several factors. For instance shrimp culture in some countries such as India and Thailand could be seriously affected by insufficient SPF-shrimp broodstocks, labor shortage, transport restrictions, delayed harvesting (results in soft-shell shrimp) and uncertainty in shrimp trade whereas in other regions including Indonesia and Vietnam the Coronavirus-side effects on shrimp industry are relatively low. This review addressed the socio-economic impacts due to COVID-19 on the shrimp aquaculture sector in 2020.

The present study was conducted to evaluate the effects of salinity levels (40, 35, 30, 25, 20, 15, 10 and 5‰) on haemolymph parameters and survival of adult shrimp Litopenaeus vannamei. Shrimps were distributed in fiberglass tanks containing water with 40‰ salinity then salinity was gradually declined during 7 days at rate of 5‰ a day by adding clean fresh water. Haemolymph of three shrimps was daily sampled from each treatment in triplicates. The haemolymph parameters including total haemocyte count (THC), total plasma protein (TPP), differential haemocyte count (DHC) were measured. Significant differences were found between treatments in terms of THC values (p<0.05). The highest THC were observed in shrimps exposed to salinities of 25 and 5‰ (p>0.05) versus the lowest THC was measured in 35‰ one. No significant difference was found in TPP levels between examined salinities (p>0.05). Hyaline cell composed 67.8 to 68% of THC (31.4 × 106 ± 0.79 × 106 cell ml-1), but those of semi-granular and granular cells were 1.8 to 2% and 29.4 to 30%, respectively. Both semi-granular and granular cell counts were significantly lower in group 10‰ throughout the experiment period. However, hyaline cells count was found to be lower in shrimps exposed to 30‰, 25‰ and 20‰ salinities (p<0.05). The semi-granular cells showed higher values in shrimps exposed to salinities of 30‰ compared to other treatments (p<0.05). In salinities of 5‰ and 10‰, the values of granular cells were the lowest. It is suggested that a declining rate of 5‰ in salinity of water per day conducting for adaptation of L. vannamei could be appropriate to the shrimp, since THC and TPP levels can be recovered every 7 days through the salinity change.

In this paper the riparian zones and water quality of Jajrud River were examined. Human and economic factors affecting the river ecosystem have been assessed for ten years. The evaluation results show that the total exploiters of agriculture, forestry and fisheries, 12.02%, the number of horticultural exploitation is 15.75%, the number of beekeeping exploitation is 18.01%, the number of active agricultural cooperatives 50%, the number of issued building permits has increased by 270.45%, the number of active service cooperatives covered by the General Directorate of Cooperatives has increased by 56.25%, the construction of freeways, highways and main roads has increased by 89.69%. Examination of qualitative parameters including nitrate, electrical conductivity, total dissolved solids, BOD5, COD, pH, phosphate and ammonium shows that BOD5, TDS and  NH4 exceeds 14 times, 16 times and 17 times more than allowable limits respectively. Surveying riparian zones shows that a total of 168 ha of areas around the river need to be rehabilitated to restore vegetation that was effective in reducing and controlling non-point water pollution.

In this study, seven aquaria were designated and 25 gold fish infected with Ich (Ichthyophthirius multifiliis) parasite were introduced to each of them. Different levels of Calcium oxide (13, 14 and 15 mg L-1) were used in three treatments of the group No 1. Three treatments in the second group received sodium chloride (1500, 2000, and 2500 mg L-1) with 72 h intervals respectively. In this study, the effectiveness of two drugs was compared through examining the normality of the data by Kolmogorov-Smirnov test and one-way analysis of variance at the level of 0.5%. The data analysis was carried out via Duncanchr('39')s discriminate test to compare the treatments with each other along with further analysis of data using SPSS 20 statistical software. In order to determine the effectiveness of drugs, wet slides were prepared from different parts of skin, fins and gills during the experimental stages and were subjected to microscopic observation. The results of this study showed that Cao 15 mg L-1 had the greatest effect on the fish gills and the fish showed the least parasites in this area (4.17 ± 2.48) (p<0.05).  The use of calcium oxide (Cao 14 mg L-1) and sodium chloride (NaCl 2500 mg L-1) had similar effects on the parasite in the gill area (p> 0.05).

One of the most important and influential stress causing problem and secondary diseases in fish is transport stress. The aim of this study was to evaluate the physiological effects of acute stress of fish transportation on some biochemicals in Salmo trutta caspius. A total of 100 fish were transported in plastic bags for 6 h and then released in 300-l tanks. Blood samples were taken after 6, 12, 24 and 48 h after a 6-h transportation (n=15). Based on the results, blood glucose increased compared to the basal value (p<0.05) after 6 h but the value was decreased at 12 and 24 h compared to that of 6 h. Cortisol value was increased significantly (p<0.05) in all sampling times.  Unexpectedly, protein content was significantly increased (p<0.05) at 24h. On the other hands, other parameters uch as Na+, Cl-, K+, did not show a significant  variation after transportation (p>0.05).

This study was aimed to assess the possibility of partial replacement of wheat flour and corn meal with Olive pomace (OP) in the rainbow trout diet through evaluating the growth, immunological, and hematological indices as well as the flesh quality. ‎To this end, a total of 3600 rainbow trout (weighting 184±0.7 g) were fed with differecnt levels of OP (2, 4, 6, 8 and 10 wt %) for 63 days, besides a control group without OP treatment. The findings exhibited no significant change in the growth indices of the experimental fish groups when compared to the control group. Among the exprimetnal groups, in general, the fish received 10% OP demonstrated the highest alterations. whereas the activity of superoxide dismutase, lysozyme, monocyte and neutrophil considerably increased when compare to the control treatment. Generally, OP inclusion decreased and increased, respectively, the saturated and unsaturated fatty acid contents of both liver and carcass tissues, especially at the higher levels. Taken together, OP could improve both health state and nutritional values of fish and the findings suggested the feasibility of partial OP replacement in the diet of rainbow trout.

Aquaculture practices always strive for the betterment of human lives and for providing cheaper resources for fish production. As fish is the most common food source all over the world, its sustainable production is very important. The use of herbs provides a cheaper way towards the progress of aquaculture. Herbs are used in place of expensive chemicals and growth enhancers. Like others, cinnamon is also a good alternate for growth chemicals. Cinnamon is an aggregate of many related species with different names depending on the environmental conditions of different landmasses. Cinnamon contains many compounds and chemicals which are important for fish growth. Cinnamon when added to fish feed makes the fish fight against stress and grow healthy than before. Cinnamaldehydes, polyphenols, carbohydrates, flavonoids, etc., boost up the immune system of fish and act as an important antioxidant and antibiotic. It fastens the growth rate of fish and enhances the other growth and blood parameters as compared to other aquaculture systems using chemicals. Moreover, the use of cinnamon as a growth and immunity promotor is cheap and environmentally friendly compared to other synthetic antibiotics.

The purpose of the present research was to investigate the effects of adding calcium carbonate nanoparticles to the Macrobrachium nipponense diet in the biofloc system under zero exchange conditions. Oriental River prawn (inital weigh of 0.82 ± 0.07 g) were divided into four groups and fed four levels of calcium carbonate nanoparticles as following 0, 25, 50 and 100  mg kg−1 diet in biofloc system (CN0, CN25, CN50, and CN100) for 28 days. This study was applied complete randomized design with three replications. Water quality parameters were measured during the test period. Feed and growth parameters and some metabolic activities of hepatopancreas were measured. Physico-chemical water factors were in the appropriate range for this species. The concentrations of total ammonia nitrogen (TAN), nitrite, and nitrate were not significantly different between the experimental groups. The growth of prawns was significantly higher and feed conversion ratio was lower in CN25 and CN50 groups compared to the control group. The lowest AST and ALT activities were observed in CN25 and CN50 groups compared to the control. The prawns fed with experiment diets had significantly higher total protein, hemocyanin, glucose, and calcium compared to the control. Overall, the results showed diets containing Nano-calcium carbonate at levels 25-50 mg kg-1 in CN25 and CN50 groups could improve growth performance and metabolic activity of oriental river prawn in the biofloc system.

With the emerging of resistant microorganisms to conventional antibiotics, as well as consumerschr('39') concerns about the side effects of chemical drugs, the tendency for natural bioactive compounds is increasing. Astacus leptodactylus is considered for export and consumption in Iran, but during its processing a large amount of waste material could be produced. The aim of the present study was to investigate the antimicrobial properties of chitosan extracted from A. leptodactylus caught from Aras Lake. The shrimp was caught from Lake Aras and transferred to the Microbiology Laboratory of the Islamic Azad University of Lahijan close to ice. Chitosan was extracted from shrimp shells, and methanol extract of shrimp tissue was prepared. Antimicrobial activity of chitosan and extracts were evaluated against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli as well as two species of Aspergillus niger and Candida albicans. Extracted chitosan showed a stronger inhibitory activity against S. aureus compared to E. coli. It was also observed that with increasing chitosan concentration, the inhibitory zone diameter increased against both S. aureus (p = 0.001) and E. coli (p = 0.122). It was also observed that the acidic solution of chitosan had a stronger antibacterial activity than aqueous solution of chitosan. The methanolic extract did not show significant effects on the studied microorganisms. Chitosan had a weak antifungal activity, although it showed a greater effect on A. niger than C. albicans.