Cryopreservation and germplasm repositories offer a variety of potential benefits to aquaculture industries. Despite this, no comprehensive repository systems exist for any prominent aquaculture species. A species that could greatly benefit from the use of cryopreserved sperm and repository storage is the eastern oyster, . High-throughput cryopreservation protocols already exist for this species, and the easy transport of frozen sperm could facilitate selective breeding programs that address pressing challenges currently faced in the industry, such as mortality due to low-salinity conditions. This study addressed the gap between cryopreservation protocols and repository development in the oyster industry by creating simulation models to evaluate cryopreservation needs at three different scales of production. The effects of high-throughput device options and three key parameters (straws per oyster, batch size, and number of operators) on production capacity, time, and cost were evaluated. Recommendations for decisions concerning cryopreservation pathways and repository creation were given at each scale of production. Relative values of broodstock, juvenile oysters, and oyster sperm sold at hatcheries were also discussed. In general, repositories operating at higher production levels benefited from the economy of scale, could use automated high-throughput equipment options, and could hire more labor without drastically increasing production costs.

The production period for salmon farming in the Black Sea comprises the winter period and is limited to seven months, due to high water temperatures during the summer time. As an alternative strategy, temporary cage submersion during the summer season might be a solution for salmon grow-out throughout the year. Therefore, this study was conducted for comparative evaluation of economic performance of submerged and surface cages, by analyzing structural costs and returns for Turkish salmon farming in the Black Sea. As a result of the temporary cage submersion strategy, economic profits increased by nearly 70%, granting higher values of financial indicators with increased net profit (685,652.5 $ year) and margin of safety (89.6%), compared to the traditional surface cage (397,058.5 $ year net profit and 88.4% margin of safety). The "What-if" analysis showed that profits from both cage systems were sensitive to variations in sale price, and the simulation by 10% reduced export market value may decrease revenues, with less financial profit loss for the submerged cage over the surface once. Hence, temporary cage submersion seems to be an alternative farm management strategy with extended production cycle and higher profits for the sustainable development of Turkish salmon farming in the Black Sea.

This study aims to develop an Excel programming model to formulate feed for Nile tilapia (), mainly for small- and medium-sized fish feed manufacturers. The model allows users to formulate the least costly balanced diet of Nile tilapia species, giving them the ability to choose a specific ingredient in the formulation according to the realities of the local environment: space-temporary availability of ingredients, prices and nutritional quality. Computer programming of a database of 25 locally available feed components was carried out using the Excel Solver Add-in and Excel IF mathematical functions to incorporate/delete specific ingredients in real time in accordance with user objectives. The theoretical characteristics of the least-cost balanced diets performed were within the margin of the nutrients requirement of the target fish size with protein levels of 35 per cent (fry diet: $1.07/kg), 32 per cent (fingerlings diet: $0.48/kg), 29 per cent (growth diet: $0.43/kg) and 27.12 per cent (final diet: $0.39/kg). The digestible energy of these diets was between 3016.5 ± 93.8 kcal. In addition, the model shows that an increase in soya meal prices by 75 per cent led the local feed industry to rely on imported fish meals, as the number included reached 52.28 per cent. However, the cost of the diet margin did not vary significantly. Nevertheless, it would be important to test the balanced diet developed with the model before production and scaling.

, a parasitic ciliate, pose a major threat to marine teleost fish aquaculture. So far, no effective and safe control method is available. In this study, the protective efficacy of a recombinant truncated surface antigen of (rCiSA32.6t) for large yellow croaker () against the parasite challenge with a sub-lethal dose of the infective theronts was evaluated by comparing the relative percent survivals (RPS), the specific antibody titers in sera, and the expression levels of the immune-related genes among the negative or adjuvant control fish, fish intraperitoneally immunized with rCiSA32.6t. The results showed that a RPS of 50.1% in rCiSA32.6t-immunized fish was achieved in comparison to negative control fish against . A significant increase was noted in the antigen-specific immunoglobulin M (IgM) and immunoglobulin T (IgT) antibody levels in the sera of the rCiSA32.6t-vaccinated fish. Compared to the negative control fish, quantitative real-time PCR analysis indicated that the interleukin-1beta, IgT, and IgM heavy chain mRNA level in the fish head kidney, spleen, gill, and skin tissue were upregulated post-rCiSA32.6t immunization. This study indicates that the rCiSA32.6t can provide a high level of immune protection against infection in grouper and is therefore pursued as a candidate vaccine.

sp. HIB_D has been observed to have nitrification activity that can oxidize ammonia/ammonium to nitrite and nitrate. This bacterium was isolated from the aquaculture environment with Ancol Indonesian marine water sources. sp. HIB_D was applied in the rearing water of to decrease nitrogen pollution levels and support a sustainable cultivation environment. This present study was set up using a completely randomized design with four treatments and three replications, i.e., control (without bacterial application) and bacterial application with a cell density of 10, 10, and 10 CFU mL in a volume of 100 mL for 90 L seawater treatment. Thirty-six individuals of 15-day-old postlarvae (PL 15) (a density of 120 PL m) were used in this study for an 8-week rearing period. Based on the water quality analysis, the ammonia level under the bacterial applications was lower than in the control after 8-week cultivation. Nitrate levels increased at week 6 and decreased at week 8, specifically in 10 CFU mL treatment. with 10 CFU mL bacterial application had the best production performance with a survival rate of 94.33 ± 2.78%, an absolute length gain of 10.59 ± 0.22 cm, an absolute weight gain of 8.16 ± 0.33 g, a specific growth rate of 14.12% ± 0.01% day, and a feed conversion ratio of 1.26 ± 0.03. The blood glucose level and total hemocyte count of shrimp under the bacterial application with a density of 10 CFU mL showed the highest level (30.71 ± 13.9 mg dL) and the lowest level (15 × 10 cells mL), respectively. The results showed that all treatments performed better than the control, in which the 10 CFU mL bacterial application was the best treatment.

The establishment of the China-ASEAN Free Trade Area has prompted closer cooperation in aquatic products trade between China and Vietnam. Studying the aquatic trade situation and export trade growth dynamics of China and Vietnam can help clarify the aquatic trade relationship between China and Vietnam and promote the sustainable development of bilateral aquatic trade cooperation. This paper analyzes the trade growth dynamics of aquatic products exported from China and Vietnam from 2002 to 2020 using the ternary marginal method. The trade growth pattern of aquatic products exported from China to Vietnam is "both quantity and price growth," and the trade growth pattern of aquatic products exported from Vietnam to China is "quantity growth mainly, extensive growth supplemented." The two countries have apparent differences in the growth dynamics of aquatic products export trade. Moreover, there is a higher complementarity when exporting Vietnam's aquatic products to China than China's aquatic products to Vietnam. Based on these, analyze the factors affecting the growth dynamics of Vietnam's aquatic products export to China: Vietnam's economic development level negatively affects the price index and quantity index of Vietnam's aquatic products exported to China, and Vietnam's aquatic product output affects the price index. China's trade freedom positively affects the price index and negatively affects the quantity index. Finally, this paper put forward suggestions to promote the sustainable development of bilateral aquatic products trade between China and Vietnam to facilitate the formulation of relevant policies between the two countries.

The way the media portrays aquaculture-related events can influence how this industry is perceived by the public and affect its success. Since media are an important source of public information, media content analysis has been carried out in several regions of the world. This study aimed to determine which aspects of aquaculture were more exposed and how they were discussed by regional media in the Madeira archipelago, an oceanic group of Portuguese islands. Analysis of aquaculture's media coverage in the two most-read regional newspapers of Madeira was carried out over a 5-year period (2017 to 2021). For each news article, the assessment focused on the geographic scope, the main topics covered, the stakeholders with access to the debate, and the general tone of the article (risk/benefit framework). A total of 297 articles were analyzed. Results indicate the occurrence of trigger events that contributed to a shift in the amount of news published and in the way media framed aquaculture. In general, political and economic issues dominated the coverage, whereas social, environmental, scientific, and landscape matters received less media attention. The voice of the government was predominant throughout the 5 years in analysis and aquaculture was generally framed with a balanced tone, slightly more negative. Open and transparent communication between the stakeholders and the media is fundamental for the sustainable development of the aquaculture industry.

Neozoa are invasive species that enter faunal communities as new species. Not infrequently, they pose a threat to local ecosystems. Climate change could further promote these developments or favor neozoa. Thus, they represent a relevant threat in the future. One of these neozoa is the copepod parasite . This parasite originates from Asia and infects a wide variety of bivalves like mussels and oysters. However, as an invasive species, it can be found more and more frequently in Europe, especially in the North and Baltic Seas. There, . poses a real threat to mussels in aquaculture and thus also to the local economy.

This study uses a stochastic bioeconomic approach to estimate the COVID-19 pandemic economic impact on shrimp farming in Mexico. Seeding-harvesting schedules - March-June, May-August, and August-November - were analyzed using shrimp prices and production costs corresponding to 2017-2019 (pre-pandemic) and 2020 (pandemic). The analyses estimated net revenue varied within 597.97-2758.88 USD$ ha and 1262.40-1701.32 USD$ ha under the pre-pandemic and pandemic scenarios, respectively. Significant decreases (38%) were estimated in net revenue values in March-June and May-August under the pandemic scenario. However, probability distributions estimated that uncertainty on the expected net revenues was not affected by the pandemic conditions, and the probability of losing was null or negligible in all the cases. Unfavorable conditions under the pandemic also required significantly higher break-even production for March-June (25.7%) and May-August (28.5%) schedules. The cost of post-larvae was the most important economic factor influencing net revenue. To conclude, although the operating conditions during the pandemic were conducive to worsening the economic outcome, no evidence still exists that uncertainty and economic risk increased compared with pre-pandemic conditions.

White spot disease (WSD) has posed a serious threat to the China and the global shrimp aquaculture. In order to diagnose (WSSV) early and prevent the spread and outbreak of WSD, it is necessary to establish a highly sensitive WSSV diagnosis method suitable for shrimp farming sites. In this study, a pre-amplification qPCR assay from the crude extract of samples heated lysis was established, which was further compared with the universal qPCR assay to verify the shrimp samples. The limit of detection (LOD) of pre-amplification qPCR assay and universal qPCR assay was 2.80 copies and 20.57 copies per reaction at 95% CI, respectively. It had good WSSV specificity and did not show cross-detection of (IHHNV), (HPV), (EHP), (AHPND), (NHPB), and (DIV1). A total of 36 shrimp samples were detected as WSSV DNA positive by pre-amplification qPCR with crude extract from samples heated lysis and universal qPCR with DNA extraction. The diagnostic sensitivity and specificity were 97.22% (85.5 ~ 99.9%, 95% CI) and 100% (81.5 ~ 100%, 95% CI), respectively. The agreement Kappa value was 0.959 (0.879 ~ 1, 95% CI), and the analysis results were basically consistent. Eliminating the tedious steps of extracting DNA and using pre-amplified qPCR to detect WSSV in shrimp, it is a good choice for aquaculture farms.

The prevalence of infectious diseases in the aquaculture industry and a limited number of safe and effective oral vaccines has imposed a challenge not only for fish immunity but also a threat to human health. The availability of fish oral vaccines has expanded recently, but little is known about how well they work and how they affect the immune system. The unsatisfactory efficacy of existing oral vaccinations is partly attributable to the antigen degradation in the adverse gastrointestinal environment of fishes, the highly tolerogenic gut environment, and inferior vaccine formulation. To overcome such challenges in designing: an easier, cost-efficient, and effective vaccination method, several encapsulation methods are being adopted to safeguard antigens from the intestinal atmosphere for their immunogenic functions. Oral vaccination is easily degraded by gastric acids and enzymes before reaching the immunological site; however, this issue can be solved by encapsulating antigens in poly-biodegradable nanoparticles, transgenic designed bacteria, plant systems, and live feeds. To enhance the immunological impact, each antigen delivery method operates at a different level. Utilizing nanotechnology, it has been possible to regulate vaccination parameters, target particular cells, and lower the antigen dosage with potent nanomaterials such as chitosan, poly D,L-lactic-co-glycolic acid (PLGA) as vaccine carriers. Live feeds such as can be utilized as bio-carrier, owing to their appropriate size and non-filter feed system, through a process called bio-encapsulation. It ensures the protection of antigens over the fish intestine and ensures complete uptake by immune cells in the hindgut for increased immune response. This review comprises recent advances in oral vaccination in aquaculture in terms of an encapsulation approach that can aid in future research.

This study aimed to evaluate the application of synbiotic containing multispecies of probiotics with different cell densities in white shrimp rearing against infectious myonecrosis virus (IMNV) and coinfection. This study used a completely randomized design with five treatments and three replications. One additional replication of each treatment was provided for the lethal sampling. Pacific white shrimp were fed with three dosages of synbiotic multispecies for 30 days, namely 10 CFU mL (Sin 3), 10 CFU mL (Sin 6), and 10 CFU mL (Sin 9), and the controls without synbiotic administration consisted of the positive control (K +) and the negative control (K -). Pacific white shrimp from all treatments, except for the K - , were challenged with IMNV a dose of 100 µL and 10 CFU mL V injected intramuscularly. Infected Pacific white shrimp showed clinical signs like anorexia, melanosis, empty gut, colorless hepatopancreas, and white necrotic areas in striated skeletal muscles, especially of the distal abdominal segments and uropod. The results showed that administration of synbiotic for 30 days resulted in higher immune parameters, such as total hemocyte count (THC), phenoloxidase activity (PO), respiratory bursts (RB), and total viable bacterial count (TBC) compared to K + /K - . After coinfection, they showed significantly higher levels for THC, PO, RB, gene expression prophenoloxidase (ProPO), and lipopolysaccharide and β-1.3-glucan-binding protein (LGBP), better clinical signs, and lower mortalities. Sin 9 treatment significantly showed the highest survival rate (SR) compared to the other treatments.

Aquaculture and fisheries are salient flourishing sectors in the world but their sustainability is often afflicted by several pathogenic diseases. Among all the pathogenic diseases of fish, parasitic diseases are found to be a major cause of concern. Argulosis is one of the dominant parasitic problems encountered in Indian aquaculture practices. s is the most prevalent argulid species harming the Indian major carp species including The major carps respond to parasitic infestation by elevating various immune relevant genes. The therapeutic chemicals, synthetic drugs and other plant extracts have made a progress in the fight against argulosis. However, there is no effective vaccine and drugs are available for this disease. Thus, designing efficient, cost-effective and eco-friendly control and treatment strategies for argulosis is presently needed. Keeping the aforementioned facts in mind, the current review elaborated the immunological interaction between and , available combat tactics, highlighted the already identified vaccine candidates to design effective control measures and illustrated the use of omics technology in future to combat argulosis.

This study aimed to develop and evaluate live and inactivated vaccines to pathogenicity in Nile tilapia. Therefore, five well-identified isolates, including A (HY1), A (HY2), A (HY3), A (HY4), and A (HY6) isolated from diseased Nile tilapia (), were used for vaccine preparation. Virulence genes detected by a polymerase chain reaction (PCR) and lethal dose determination were conducted. Nile tilapia, each with a body weight of 25 ± 0.5 g were divided into six experimental groups (each of 20): T1 group (control), fish were injected with saline as a negative control, T2 group (formalin-killed vaccine) for the A (HY2) strain, T3 group ( formalized killed vaccine) for the A (HY4), T4 group (autoclaved vaccine) for the A (HY2), T5 group (autoclaved vaccine) for A (HY4), and T6 (live vaccine) for A (HY1), triplicate. At the end of the immunization period, all groups were challenged by , A (HY2). Blood samples were drawn 21 days post-immunization and 3 days after the challenge test for antibody titer assay. The results showed that the pathogenicity of strains A (HY2) and A (HY4) was the strongest, as the lethality rates (LR) were 100% and 90%, respectively, whereas the pathogenicity was moderate for strains A (HY3) and A (HY6) (LR 60% for each). A (AY1) was the weakest strain as no dead fish was found for this strain. The presence of , and genes as the main cause of the pathogenesis. The best protective efficacy was obtained from the live vaccine, A (HY1) with a protective rate of about 94.12% (relative percentage of survival, RPS), compared to autoclaved killed vaccines and formalin-killed vaccines. Based on immunoglobulin estimation (IgM) and RPS%, our data concluded that A (HY1) live vaccine had the best vaccine prophylactic effect against the highly pathogenic strain A(HY2).

The COVID-19 pandemic-induced lockdown has indisputably affected the aquaculture industry across the globe. India imposed a nationwide lockdown to contain the outbreak of COVID-19 that disrupted normalcy and economic activities. The fisheries sector was also highly affected. Hence, a study was conducted from July to December 2020 to understand the stakeholders' perception of the impact of COVID-19 lockdown, wherein 517 stakeholders participated (online) in the first stage. The policy reforms suggested by the stakeholders were referred to the fisheries experts in the second stage for prioritization towards implementation. Data analysis depicted that a majority (81%) of the stakeholders were aware of COVID-19 lockdown impacts on their businesses. Due to this unprecedented lockdown, labour availability was hampered, transport facilities were fully halted and access to inputs like seed, feed, and advisory were largely affected. Importantly, all stakeholders unanimously adduced to the uncertainty over the future of the fisheries sector. Moreover, fishery experts feel that enabling policies for the promotion of awareness, appropriate training, and transparency in the implementation of schemes, credit facilities, and price regulation can have a massive positive impact. Furthermore, the study also recommends utilizing the potential of e-resources (ICTs and IoT) to digitize the business networking of fishery sector stakeholders.

This paper offers new insights into gender norms, roles, participation, relations, and benefits derived by women and men engaged in the aquaculture sector in Ogun and Delta States in Nigeria. Data were collected using mixed methods, including structured surveys of 410 farmers, 175 market actors, and 53 input suppliers, 116 semi-structured key informant interviews, and 11 focus group discussions (FGDs). Overall results of the study revealed the linkages within the aquaculture value chain, which was highly gendered, with men dominating all the three main stages of the value chain as indicated by Duncan's index of dissimilarity of 17.35%. Results also revealed a gender difference in the value of assets, ownership, and wage rate among men and women participants in paid labor in the input supply and fish trading segments. Men tended to realize more profits than women, indicating an imbalance in the distribution of benefits by gender along the aquaculture value chain. Results revealed that the participation of women in decision-making was relatively high, attributable to their involvement in aquaculture value chain activities. The findings highlight the need for governments, development agencies, and non-governmental organizations to address gender disparities in policies designed to improve the imbalance in the distribution of benefits between women and men.

The current study evaluated the biosafety of oxytetracycline (OTC) exposure for 30 days in monosex fries. The fries were exposed to OTC for 3 h/day for 30 days at 350 (0.5X), 700 (1X), 2100 (3X), 3500 (5X), and 7000 (10X) mg/L and compared with control (0X). The OTC exposure at 5X and 10X concentrations caused 100% mortality within 4 days and 5 min, respectively. The mortalities recorded in 0.5X, 1X, and 3X groups were 3.33 ± 1.15%, 14.67 ± 1.15%, and 47.33 ± 11.37% on day 30, respectively. The feed intake was decreased up to 23.33% in the 3X group during the exposure period. The OTC residue levels on 30-day exposure were 216.53 ± 14.71, 450.56 ± 44.31, and 1141.26 ± 63.64 μg/kg, which reduced to 40.40 ± 3.25, 76.68 ± 2.77, and 95.61 ± 5.13 μg/kg after 15 days of termination of exposure in the 0.5X, 1X, and 3X groups, respectively. The histopathological changes observed in the 1X group were epithelial detachment, desquamation of secondary lamellar epithelium, lamellar fusion, and inflamed cartilaginous core in the gills, alteration in the integrity of gut mucosa, degeneration of muscularis mucosae and necrosis in the intestine, the disintegration of the nephritic tubule, necrosis, and glomerulopathy in the kidney, and dilated vascular duct, necrotized hepatic tissue, diffused hepatic parenchyma, vacuolation, and fatty changes in the liver. The OTC exposure induced marked tissue changes histologically in a dose- and time-dependent manner, which undoubtedly reduced the growth of tilapia.

Development programs have intensified support for the aquaculture sector to improve production and productivity, as well as food security and diet quality for smallholder farmers. This paper examines the impact of farmers' participation in Common Interest Groups (CIGs) and the effects of aquaculture development support programs on the net returns and productivity of tilapia fish in Kenya. The study used household-level data of 506 members of the CIG who were randomly selected for the treatment group and benefited from Aquaculture Business Development Program (ABDP) interventions. The analysis employed an endogenous switching regression model to account for selection bias. The results reveal that membership in CIGs and receiving fish production interventions have resulted in a 32.3% increase in tilapia fish sales returns and a 6.6% increase in tilapia fish yields. Specifically, ABDP interventions are aimed at providing fish producers with ponds and cages had a significant and beneficial effect on fish yields and income returns. This finding suggests that policies with targeted interventions that support aquaculture infrastructure can play a significant role in increasing the incomes of smallholder farmers and reducing rural poverty in Kenya.

Women's empowerment and gender equality are key goals for development and human rights. However, a significant gap still exists in achieving these twin goals. Formulating appropriate strategies for women's empowerment requires first understanding context-specific patterns and sources of disempowerment. We use data collected using a questionnaire survey from 1653 households in Rangpur and Rajshahi districts in Bangladesh. Guided by an analytic tool that measures women's empowerment, inclusion and agency (the project level Women's Empowerment in Fisheries and aquaculture Index (pro-WEFI)), and using seven empowerment indicators, we provide findings on the status of women's empowerment, participation, and engagement in aquaculture in Bangladesh. Results show that women were highly involved in making household decisions, mainly jointly with their husbands. However, data suggest a substantial gap in women's access to financial services, in participation in aquaculture activities, and in access to and control over productive capital and remuneration for aquaculture labor. Finally, despite some women achieving adequacy on some indicators, most women in fish farming households in Bangladesh lack adequacy on many of the selected indicators.

Globally, aquaculture has faced serious economic problems due to bacterial, viral, and various other infectious diseases of different origins. Even though such diseases are being detected and simultaneously treated with several therapeutic and prophylactic methods, the broad-spectrum activity of vaccines plays a vital role as a preventive measure in aquaculture. However, treatments like use of antibiotics and probiotics seem to be less effective when new mutant strains develop and disease causing pathogens become resistant to commonly used antibiotics. Therefore, vaccines developed by using recent advanced molecular techniques can be considered as an effective way of treating disease causing pathogens in aquatic organisms. The present review emphasizes on the current advances in technology and future outlook with reference to different types of vaccines used in the aquaculture industries. Beginning with traditional killed/inactivated and live attenuated vaccines, this work culminates in the review of modern new generation ones including recombinant, synthetic peptides, mucosal and DNA, subunit, nanoparticle-based and plant-based edible vaccines, reverse vaccinology, and monovalent and polyvalent vaccines.

Microalgae are the foundation of oyster diets in aquaculture. As demand for oysters increases, so does the need for nutritionally complete diets. is considered the optimal oyster diet and is often supplemented with other algae like to provide complementary nutrients, but which diet do the oysters prefer, and what effects do the diets have on physiology? This study performed feeding experiments with single ( or ) and mixed (both genera combined) diets in Pacific oysters (). Oysters fed exclusively had greater biomass gains but reduced shell growth, evidenced by a lower Oyster Condition Index, and gene expression analysis showed compensatory upregulation of the biomineralisation gene nacrein in this group Oysters fed mixed diets showed higher algal cell clearance and pseudofaeces production, and within the mixed diet, a preference for . This suggests that whilst a mixed-algae diet is traditionally used, a single species diet of can significantly enhance oyster growth, reducing the need for complex multi-species algal culture. Culturing one alga is more time- and cost-effective, but stage-specific diets could promote specific physiological factors. These findings can help to optimise oyster feeding in a world with increasing demand for oysters.