Sustainable Aquaculture and Health Management Journal
Volume:8 Issue: 2, Summer and Autumn 2022

Food fish farming is regarded as one of the most important sectors of the aquaculture industry. Salmon farming is a major contributor to the growth of the aquaculture sector. Climate change is predicted to have a complex impact on aquatic ecosystems, including fisheries and aquaculture. Climate change can cause a fluctuation in water temperature of rivers, lakes, seas, and oceans. This can change the pattern of ocean currents and marine productivity to be redistributed, especially to higher latitudes, and reduce the global concentration of phytoplanktons, increasing ocean acidity, creating deoxygenated zones, and inducing episodic shocks to marine systems. However, the impact of climate change on fish health is not limited to the physical changes in the environment. A change in climate can also influence the incidence of infectious diseases by shortening generation times and/or increasing the survival rates of the pathogenic agents, improving disease transmission, and enhancing the host's susceptibility to the pathogens. The actual impact of climate change on infectious diseases, particularly those caused by bacterial agents, is not fully understood in both wild and captured fish species. This review addressed the impact of climate change on outbreaks of salmonid bacterial diseases and discuss the present gaps.

One hundred and fifty stellate sturgeon (Acipenser stellatus, 250 ± 3.24 g) were assembled into 15 round concrete tanks. The tanks were allocated to five treatments with three replications: fed with a diet containing 30% protein for eight weeks (T1); fed with a diet containing 30% protein level in weeks 1, 3, 5, and 7 and fed with a diet containing 35% protein level in weeks 2, 4, 6, and 8 (T2); fed with a diet containing 30% protein in weeks 1, 2, 5, and 6, and fed with a diet containing 35% protein in weeks 3, 4, 7, and 8 (T3); fed with a diet containing 30% in the diet in weeks 1, 2, 3, and 4, and fed with a diet containing of 35% protein in weeks 5, 6, 7, and 8 (T4); and fed with a diet containing 35% for eight weeks (T5). Remarkable effects were recorded in growth efficiency, and T2 and T5 had higher growth than other treatments. No marked difference was seen in the whole body composition. Different feeding strategies affected RBC, WBC, and MCV, and RBC and WBC of fish in the T4 were notably upper than in the other groups. Different feeding strategies had marked differences in lysozyme and ACH50 activity. These results demonstrated that T2 could use as a feeding strategy for stellate sturgeon.

The principled use of agricultural pesticides and prevention of their negative consequences requires environmental management with a comprehensive and long-term approach. This article is done with the aim of strategic analysis of the environmental management of the effects of agricultural poisons with an emphasis on Butachlor poison. The current research is a non-experimental (descriptive) research in terms of its practical-developmental goal and data collection method, which was conducted in a survey method. The statistical population included persons who are in charges in this approach. Sampling was done by purposeful method and theoretical saturation was achieved with 8 people. The effects of agricultural pesticides were identified using semi-structured expert interviews of internal and external factors of the environmental management model with qualitative thematic analysis. Then the analysis of factors and presentation of suitable scenarios was done using SWOT analysis and Quantitative Strategic Assessment Matrix (QSPM). MaxQDA software was used to perform thematic analysis, and SWOT analysis calculations were performed in Excel software. Based on the evaluation matrix of internal and external factors, the appropriate strategy for environmental management of agricultural toxic effects should minimize environmental pressures and threats by improving and strengthening internal weaknesses. Based on the quantitative strategic planning matrix analysis, the best scenario is the formulation of laws and regulations about the amount of poison consumption.

In this regard, the present study is aimed to assess the effect of chitosan and Satureja khuzestanica essential oil (SKEO) on the prolongation of the shelf life and quality of Mugil cephalus L fillet. Edible coating based on biopolymers and phenolic compounds is an effective way to preserve the quality of fish.  There is a growing demand for bio-based and active packaging as one of the preferred emerging technologies to improve food quality and extend shelf-life. To this end, the influences of various variables such as storage time (0, 7days+12hours (7.5) and 15 days), storage temperature (-10, -3, and 4 ℃ ), and essential oil content (0.5, 1 and 1.5) were assessed on the shelf life of M. cephalus fillets through the use of RSM software. A significant rise was observed in the pH of all samples by increasing the storage time (p<0.05).Thiobarbituric acid and nitrogen bases (mainly composed of trimethylamine, dimethylamine, and ammonia), as well as peroxid, also increased by prolonging the storage time and reached their highest level at the end of the storage period (p<0.05). On days 7.5 and 15, treatment (temperature of -3℃, and 2% essential oil) and treatment (temperature of -10℃ and essential oil of 2%) showed the lowest microbial load (2.39± 0.55 and 5.96± 0.23 log cfu/g, respectively) while the highest microbial load was detected in the treatment involving 0.5% essential oil and storage temperature of 4℃  (p<0.05). Based on sensory tests, no significant difference was observed in the total acceptance of the treatments. The results of the current research indicated that coating with chitosan (2%) and S. khuzestanica essential oil (especially 1%) can enhance the storage time of M. cephalus fillets in the refrigerator.

The aim of the present study was to evaluate the physico-chemical criteria of yogurt fortified with fish protein hydrolysate (FPH) obtained from Fresh Abu mullet (Planiliza abu) fish weighing 40 g during 21-day refrigeration. A hundred milliliters of final milk were inoculated with starter culture, and fermented for 4-5 hours until the pH reached to 4.6. The yogurts were divided in two groups in triplicate and each group was prepared in triplicate. Yogurts supplemented with nanoencapsulated hydrolysates exhibited a slight reduction in pH and augmented acidity particularly up to three weeks of refrigeration. The pH of nanoemulsion-FPH yogurt was initially 4.52 and reached 4.01 in third week with a significant difference (p<0.05) compared with that of the control at the same time (3.80). The pH value of the fortified yogurt showed acceptable limit on day 7 (4.35) but it was remarkably decreased on day 14 (4.19, p<0.5). The upmost and the least values of viscosity of nano-FPH yogurt samples were respectively 4187.3 and 4046.6 (cps) on days 1 and 21. The viscosity values of control were ranged from 3716.0 to 4042.0, respectively in 21 and 1 days of refrigeration. Moreover, the maximum and minimum water holding capacity (WHC) value of nano-FPH yogurt samples 92.5% and 86.2%, respectively on days 1 and 21. It is concluded that the incorporation of the FPH in the form of nanoencapsulation offered superior physico-chemical advantages than those of control yogurt samples.

Study on pedigree information and genetic diversity is essential for effective management of hatcheries. In this study we used six microsatellite loci for analysis of offspring parentage from two sets of brooders, to evaluate the genetic diversity and parental contribution in the production of progeny of Hypophthalmichthis molitrix. The effective number of alleles and the heterozygosity for parents and offspring was (3.63 and 4.38) and (0.943 and 0.960) for two groups, respectively. The contribution of the females and males to the offspring for the two groups was 61% and 91%, respectively. Females mated with 2–6 males, and males fertilized 2–5 females, revealing multiple paternity in this species. Our results revealed that the ratio of males to females plays an important role in parental contribution to offspring production. Despite a decrease in the heterozygosity among larvae towards their parents, the values obtained were still acceptable, which supports the hypothesis of genetic factors involves in mating patterns selected by parents to maintain the proper levels of heterozygosity in their progenies.