Aquaculture Sector Research Articles

Developing production and financial benchmarks for marine aquaculture from farm data

Benchmarking programs for crop and livestock farms have been used by farmers to identify ways to improve farm efficiencies. This study developed a set of benchmarks for oyster, mussel, and seaweed farming in Maine (USA). Farm-level survey data were used to calculate benchmarking metrics for each farm respondent. Results showed the importance of disaggregating benchmarking metrics by production scale, gear type, and whether farms were initial startup (defined in this study as <5 years in business) or established (>5 years in business) farms. The initial analysis of cost structures on individual farms provided useful information from which to identify key categories for disaggregation. Identification of the most important cost inputs further points to which benchmarks will be of greatest value for different groups of farms. Results for oyster farms showed that startup costs per oyster harvested were lowest ($0.20/oyster) on established bottom culture farms as compared to $0.96/oyster for established suspended oyster farms, and highest ($1.75/oyster) on startup oyster farms. Profits (Net Farm Income) per oyster were greatest on established bottom oyster farms followed by established suspended oyster farms, but were negative on average, for startup farms. Per-hectare, however, profits were greater on established suspended than bottom culture oyster farms. Labor efficiencies were also greatest for established suspended oyster farms (65 oysters/hour of labor), followed by established bottom culture oyster farms (55 oysters/hour of labor), with the lowest labor efficiency (44 oysters/hour of labor) for startup oyster farms. Given the inherent variability among aquaculture farms, adequate numbers of observations of participating farmers are necessary within each production scale/gear type and startup/established categories for benchmarks to be of value. For emerging sectors of aquaculture, benchmarking metrics can be useful for navigating the critical startup period, but obtaining sufficient numbers of observations is a challenge. Benchmarking metrics for established farm businesses provide guidance on the levels of production and economic performance necessary to be successful. Overall, benchmark values are most useful when applied in a holistic fashion that takes into consideration the performance of the farm across all production, revenue, expense, and efficiency categories (labor, capital, and financial).

The fisheries and aquaculture sector in Latin America: Exports to East Asia and production.

The Asian giant has agitated foreign trade in Latin America due to easy access to this market, tariff policies, and international agreements. In the face of a globalized world, in the last decade fisheries and aquaculture entrepreneurs of Latin American countries have taken on the challenge of getting their products known at International Fisheries and Aquaculture Exhibition fairs in Asian countries, which has generated an increase in the exportation of their products. Fishing and aquaculture exports are a variable of the economy of each country reflected in the gross domestic product and foreign exchange results. The present research work analyzed the fishing and aquaculture sector through the first difference Generalized Method of Moments estimator to establish the behavior of exports from Latin American countries to Asia, the production of each Latin American country, and the subsequent effect on the economic growth of the fishing and aquaculture sector during the period 2012–2019. The findings of this article suggest the significant positive relationship between output and economic growth, and a non-significant negative relationship between exports to East Asia and the economy.

Benefits of Carotenoid Astaxanthin: A Review

Astaxanthin is a high value keto-carotenoid pigment renowned for its commercial application in various industries such as aquaculture, food, cosmetic, nutraceutical and pharmaceutical sectors. It is commonly employed in salmonid and crustacean aquaculture to give the pink hue that these species are known for. Scientific literature reviews have persistently demonstrated the instrumental role of astaxanthin in targeting several animal health conditions. Most importantly, the profound effect on pigmentation, where astaxanthin is frequently utilized as an additive in formulating diets to boost and improve the coloration of many aquaculture farmed species, subsequently product quality, consumers’ acceptance and market demand are increasing, and revenue generated. Moreover, the wide range of other physiological benefits of astaxanthin includes various improvements in survival, growth performance, reproductive capacity, stress tolerance, and disease resistance as well. Also, astaxanthin has some other applications like, it is an anticancerous agent, it can prevent diabetes and cardiovascular diseases and enhances nutritional qualities. Astaxanthin products are used for commercial applications in the dosage forms as tablets, capsules, syrups, oils, soft gels, creams, biomass and granulated powders. Astaxanthin patent applications are available in food, feed and nutraceutical applications. This manuscript basically reviews the current available evidence regarding biological sources of astaxanthin, extraction procedures, stability, biological activity, health benefits, and commercial uses.

Closed life-cycle aquaculture of sea lettuce (Ulva fenestrata): performance and biochemical profile differ in early developmental stages

Sea lettuce (Ulva) aquaculture has increased the last decade due to high productivity, wide environmental tolerance, and interesting functional and nutritional properties of the crop. Research focus has mainly been on adult biomass production, but knowledge of performance and biochemical content of early developmental stages – which are the basis to any large-scale production - is still limited. The life-history ofUlvaalternates between a diploid sporophytic life-stage and a haplontic gametophytic life-stage. Whereas the sporophyte give raise to recombinant gametophytes through zoids, gametophytes can give raise to parthenogenetically developing, clonal gametes in absence of a mating partner. This study shows that recombinant gametophytes have a faster ontogenetic development, higher growth rate, as well as higher protein, fatty acid, and pigment contents compared to clonal gametophytes of the cropUlva fenestrata. Nutrient addition is required for a normal development, but temperature and swarmer density have relatively small effects on the hatchery success, relative growth rate and biochemical profile of the juvenile biomass. Our study reveals that the selection of the life-history-phase in novel sea lettuce crop strains could largely contribute to the emerging seaweed aquaculture sector.

The Impact of Climate Change on Bivalve Farming: Combined Effect of Temperature and Salinity on Survival and Feeding Behavior of Clams Ruditapes decussatus

European clam (Ruditapes decussatus) is one of the most relevant emergent bivalve species from the aquaculture sector in Europe with high economic value. Climate changes represent a potential limiting factor to this activity, directly interfering with the survival and behavior of bivalves. Severe fluctuations in temperature along with periods of heavy rainfall or periods of drought that significantly change the salinity can promote physiological stress in bivalves, resulting in changes in physiological and behavioral responses and, in extreme cases, leading to high mortalities. This study aimed to evaluate the combined effect of temperature and salinity on mortality and feeding behavior of R. decussatus. Juveniles and adults were exposed to combined ranges of temperature (5°C–35°C) and salinity (0–40). Mortality and feeding behavior were registered every 24 h of each 120-h trial. A control temperature range was set between 15°C and 23°C, where mortality and feeding behavior were considered as the normal scenario. Our data suggested salinity 15 as a “turning point,” a point from which occurred distinct patterns in mortality and feeding behavior. The results evidently indicate that abrupt reductions in salinity and sharp increases in temperature will lead to high mortality of R. decussatus. Juveniles were revealed to be more sensitive to the increase of temperature in a less saline environment, to suffer greater and faster mortalities, and to be more resistant to extremely high temperatures under more saline conditions. The high temperatures and sporadic heavy rainfall that are predicted to occur in the south of Europe due to climate changes will contribute to compromise the recruitment of European clam, thus threatening the production of this species and consequently impacting the economic sector.

Manila clam and Mediterranean mussel aquaculture is sustainable and a net carbon sink

Aquaculture is a globally expanding industry that contributes to feeding an increasing global population. Shellfish cultivation is one of the largest sectors of aquaculture and one of the few food productions that have the potential capacity of acting as carbon sink. In fact, >90 % of bivalve shells are calcium carbonate (CaCO3), synthetized during biocalcification process, which incorporates a molecule of CO2. Manila clam (Venerupis philippinarum, Adams & Reeves, 1850) and Mediterranean mussel (Mytilus galloprovincialis, Lamarck, 1819) are two of the major groups of cultivated shellfish. Our aim was to assess the potential role of those two bivalve species in the overall marine carbon balance using an ecosystem approach, and to evaluate if they can be definitely regarded as carbon sink. The contribution to CO2 emissions (as CO2 eq./kg of fresh products) due to mollusk farming has been also calculated as carbon-source term by means of Life Cycle Assessment (LCA). LCA is nowadays the most shared and accepted tool for evaluating the environmental impacts of aquaculture productions. As a case study, the Sacca di Goro coastal lagoon (Northern Adriatic Sea, Italy) has been considered, because it is the premier site in Europe for clam farming, and one of the most important for mussels. Our study has shown that for each kilogram of harvested and packaged clams and mussels, shell formation throughout the mollusk growth allows to permanently capture 254 and 146 g of CO2, in the face of 22 and 55 g CO2 eq. emitted for farming, respectively. As a result, clams and mussel aquaculture could be considered as a carbon sink, with a net carbon capture capacity of 233 and 91 g CO2/kg of fresh product, respectively. In a wider context, bivalve aquaculture could be included in the carbon trading system and played a role towards the carbon-neutral economy.

Assessing the Economic Impacts of COVID-19 on the Aquaculture and Fisheries Sectors in Relation to Food Security: A Critical Review

The aquaculture and fisheries sectors are critical sources of nutrition and employment generation in many developed and developing countries. Hence, any disruptions to these sectors due to the COVID-19 pandemic have a far-reaching impact, leading to a cascading chain of disorder affecting people’s food security and livelihoods. Relating to these fish sectors, we reviewed COVID-19’s implications for the food security of these vulnerable countries. The current study indicated that COVID-19 and its related preventive measures have severely disrupted the fish demand and supply chain by creating considerable fish price volatility. As a result, the vulnerable aquatic communities have adopted several short-term coping strategies, including fish overwintering, delayed fish stocking time, and feeding the overcrowded fish with low-priced food. Since the long-term coping strategies are still unclear, we recommended certain longstanding methods that are likely to safeguard food security and livelihoods if adopted.

Prevalence, Antimicrobial Resistance and Resistance Gene Cassettes Detection in Bacterial Pathogens Isolated from Freshwater Ornamental Fishes

Background: Antimicrobial resistance (AMR) is a rising concern in the global aquaculture sector due to the rampant prophylactic use of antibiotics. This study is aimed to determine the AMR pattern in freshwater ornamental fishes. Methods: Fish pathogens were isolated and identified from infected Guppy and Molly collected from ornamental fish farms. Antibiotic susceptibility testing (ABST) using disc diffusion with 36 antibiotics was performed following the disc diffusion method. The resistance gene cassettes such as Class 1 and Class 2 integron were also detected from resolved isolates. Result: Fish pathogens were isolated and identified as Aeromonas hydrophila, A. dhakensis, A. veronii, A. sobria, Bacillus subtilis, Comamonas testosteroni, Edwardsiella tarda, Enterobacter cloacae, Enterococcus faecalis, Kurthia gibsonii and Klebsiella aerogenes. Shannon Weiner diversity index of resolved isolates was found to be 1.366 and 2.101 for Guppy and Molly, respectively. ABST results showed an elevated resistance pattern for A. veronii, E. faecalis (Guppy), K. aerogenes, B. subtilis, E. faecalis, C. testosteroni (Molly) with higher multiple antibiotic resistance indexes ( greater than 0.33). Meanwhile, all the recovered isolates were susceptible to sulphafurazole, enrofloxacin, norfloxacin and ciprofloxacin. Detection of class 1 integron in genomic and plasmid DNA reminds the rapid spread of the AMR gene through horizontal gene transfer.

Replacement of fish meal by black soldier fly larvae meal in diet for goldfish Carassius auratus: Growth performance, hematology, histology, total carotenoids, and coloration

Black soldier fly (Hermetia illucens) larvae meal (BSFLM) is a promising animal feed ingredient because of its high protein content and sustainable nature in the aquaculture sector. For the potential application of this ingredient in goldfish culture, five isonitrogenous (42% of crude protein) and isolipidic (9% of crude fat) diets were prepared to replace 0, 43, 84, 145, and 210 g kg−1 fish meal (FM) with BSFLM (termed BSFLM0 – BSFLM210). Triplicate groups of 20 goldfish (approximately 9.35 ± 0.02 g fish−1) per tank were randomly assigned one of the experimental diets and fed three times daily to satiation for 10 weeks. Dietary inclusion of BSFLM linearly increased final body weight, weight gain, and specific growth rate (P < 0.001), and linearly and quadratically improved feed conversion ratio, protein efficiency ratio, and protein productive value (P < 0.05). The highest weight gain was observed in the BSFLM145 (15.61 g fish−1) group without a significant difference (P > 0.05) with BSFLM210 (14.76 g fish–1). Organosomatic indexes were similar among dietary treatments (P > 0.05). Whole-body moisture and ash contents were not significantly affected (P > 0.05), but crude protein and fat content were affected by BSFLM inclusion (P < 0.05). Regarding muscle fatty acid composition, C12:0 and C14:0 increased linearly and quadratically with BSFLM levels, resulting in an increase in total saturated fatty acids with linear and quadratic effects (P < 0.05). In contrast, C18:3n-3, C20:5n-3, C22:6n-3, total polyunsaturated fatty acids, total n-3, and n-3/n-6 ratio decreased with increasing levels of BSFLM. The color index (a* value) was linearly and quadratically decreased in the abdominal region by BSFLM inclusion, similar to the decrease in L* and a* values in the head region. Total carotenoid contents also decreased in fin, skin, and serum by BSFLM inclusions (P < 0.05). BSFLM inclusion decreased aspartate aminotransferase, alanine aminotransferase, total cholesterol, and low-density lipoprotein cholesterol with linear and quadratic effects (P < 0.05). A mild degree of vacuolization with swollen hepatocellular was observed in the BSFLM84 group, being more abundant in BSFLM145 and BSFLM210 groups. Overall, dietary BSFLM inclusion improved growth performance, feed utilization, and blood biochemistries in goldfish, but it exerted a negative effect on carotenoid content, skin coloration and liver histological integrity.

Pemanfaatan Jeroan Ikan Dengan Limbah Kulit Jagung Sebagai Pakan Alternatif Ikan Lele

The demand for freshwater consumption fish, especially catfish, is so fast that the aquaculture sector needs to be increased again. The supporting factor in the success of aquaculture is feed, where feed for catfish cultivation on Timor Island, NTT is still much more expensive than on the island of Java, this is an inhibiting factor for the success of cultivation on Timor Island. These problems can be overcome by making independent feed. The purpose of this activity is to determine the potential of local raw materials or waste in Timor Island as raw materials for making fish feed. The method used is a descriptive method where research describes the phenomenon or individual characteristics, the situation accurately in a certain group. Based on the results obtained that the waste on the island of Timor, namely fish offal and corn husks can be used as raw materials for making feed and has a fairly good buoyancy shown by being able to float for more than 5 minutes.

Is tilapia mortality a latent concern for the aquaculture sector of Bangladesh? An epidemiology and health economic impact study

Tilapia are the 3rd most culturedaquaculture species in global aquaculture, produced in over 170 countries. Bangladesh is the world's fourth-largest tilapia producer and yet only few studies have been conducted to understand factors associated with tilapia mortality and economic losses. Using an online tilapia epidemiology and health economics survey tool, we surveyed 565 tilapia farms in 15 of Bangladesh's most important tilapia-producing districts. The study examined a range of factors, including geographic locations, farm characteristics, water source, stocking, biosecurity measures, baseline and unusual mortality levels and characteristics. For the period January 2017 to February 2019 a total of 18.2% of farms (103 out of 565) reported having experienced unusual mortality, with an average mortality level of 23.2% (range 3 to 90). A number of factors were found to be significantly associated with reporting of unusual mortality occurrences, including farmer education level, farm size, farm biosecurity measures, baseline mortality level, farmer concern about baseline mortality, dead fish removal frequency and disposal method and antibiotic treatment. Farming region, water source, dead fish removal frequency, and antibiotic treatment were all found to be significantly associated with the level of unusual mortality, with water source and dead fish removal frequency remained significant in the multivariable model. Major clinical signs linked with these mortalities included skin erosions, hemorrhagic lesions, open wounds, skin discoloration, exophthalmos, abdominal distension, swelling, scale protrusion and eye opacification. Based on baseline and unusual mortality in tilapia, a total hidden loss of 875.7 million USD annually was estimated. To ensure the future sustainability of tilapia production, the authors recommend more investigations of unusual mortalities events with collection of metadata and clinical samples for disease diagnostics, coupled with nationwide farmer awareness campaigns.

Pathogenicity, diagnosis, prevention strategies and immune response of bacterium Nocardia seriolae : A critical review

Nocardia seriolae, an opportunistic and facultative intracellular Gram-positive bacterium, is mainly responsible for nocardiosis in fish. Nocardiosis is a chronic, granulomatous and systemic disease in which lesions are found in the skin as well as several internal organs such as the kidney, liver and spleen with the distinctive nodular granuloma structure. N. seriolae is capable of infecting a wide variety of fish species which poses a devastating impact on the aquaculture sector around the globe, particularly in Asia. Due to the lack of appearance of nocardiosis symptoms at the earlier stages, multiple epidemics of nocardiosis causing high mortality have been recorded. To this end, numerous epidemiological studies have been carried out to characterize and identify Nocardia spp. through several detection techniques, which have favoured the formulation of a multitude of antibiotics and vaccines. After bacterial resistance to antibiotics, nowadays, vaccination has been considered the more appropriate strategy to treat nocardiosis. For valuable information related to N. seriolae and to combat fish nocardiosis, this review extended the existing knowledge, including pathogenesis, virulence characteristics, rapid detection techniques, host immune response and prevention strategies against N. seriolae infection in fish species in aquaculture.

Vibriosis Outbreaks in Aquaculture: Addressing Environmental and Public Health Concerns and Preventive Therapies Using Gilthead Seabream Farming as a Model System.

Bacterial and viral diseases in aquaculture result in severe production and economic losses. Among pathogenic bacteria, species belonging to the Vibrio genus are one of the most common and widespread disease-causing agents. Vibrio infections play a leading role in constraining the sustainable growth of the aquaculture sector worldwide and, consequently, are the target of manifold disease prevention strategies. During the early, larval stages of development, Vibrio species are a common cause of high mortality rates in reared fish and shellfish, circumstances under which the host organisms might be highly susceptible to disease preventive or treatment strategies such as vaccines and antibiotics use, respectively. Regardless of host developmental stage, Vibrio infections may occur suddenly and can lead to the loss of the entire population reared in a given aquaculture system. Furthermore, the frequency of Vibrio–associated diseases in humans is increasing globally and has been linked to anthropic activities, in particular human-driven climate change and intensive livestock production. In this context, here we cover the current knowledge of Vibrio infections in fish aquaculture, with a focus on the model species gilthead seabream (Sparus aurata), a highly valuable reared fish in the Mediterranean climatic zone. Molecular methods currently used for fast detection and identification of Vibrio pathogens and their antibiotic resistance profiles are addressed. Targeted therapeutic approaches are critically examined. They include vaccination, phage therapy and probiotics supplementation, which bear promise in supressing vibriosis in land-based fish rearing and in mitigating possible threats to human health and the environment. This literature review suggests that antibiotic resistance is increasing among Vibrio species, with the use of probiotics constituting a promising, sustainable approach to prevent Vibrio infections in aquaculture.

Country-specific food culture and scientific knowledge transfer events – Do they influence the purchasing behaviour of seafood products?

A positive perception of aquaculture products is essential to boost production by using more sustainable and eco-friendly solutions. However, consumer perception and resulting purchasing decisions remain poorly understood. In most European countries, the consumer perception tends to be rather negative, which is reinforced by knowledge gaps and misleading information from the media. This is believed to have the greatest impact on the current low consumption rate of farmed fish across Europe. Previous research has suggested that consumers may often be reluctant to change their seafood purchasing behaviour despite having a solid scientific understanding of aquaculture products and their mode of production. In this study, we investigated the extent to which country-specific contexts and degree of scientific knowledge contribute to the purchasing behaviour of consumers across Europe. To this end, interactive poster surveys and semi-structured interviews were conducted at eight different knowledge transfer events (KTEs) across three countries, targeting 383 participants. The application of a yet underutilized method, an interactive poster survey, underscored the need to use new approaches to tackle consumer behaviour.Our results indicate that increased scientific knowledge does not lead to changes in purchasing behaviour per se. Perceptions and purchasing habits are very contextual and vary from culture to culture. This points to the highly interlinked nature of country-specific marine food culture that ranges between individual awareness, scientific knowledge, and socio-cultural contexts, all of which renders in resulting individual purchasing decisions. Our results suggest focusing more on the sustainability of a product and emphasising the ongoing transition towards a circular economy approach in the aquaculture sector may be a promising pathway to foster more sustainability-driven purchasing decisions in the seafood sector. Our findings also question whether trying to educate the public about more sustainable purchasing criteria is really the key to foster more sustainable consumption patterns or whether we are working from misleading assumptions that lead to wrong approaches. In conclusion, a lack of clear and easily accessible information appears to be the main barrier to social acceptance of sustainable aquaculture products in Europe.

Pharmacotherapeutic potential of astaxanthin: Human and animal targeting roles – A review

Abstract The recent pandemic stress and the impacts of climatic changes on humans’ and animals’ health status and well-being resulted in severe drawbacks. Initially, stress-induced oxidation resulting from the generation of free radicals led to the impairment of cellular function and a high possibility of attack with infection. Astaxanthin is a bioactive material derived from fish, crustaceans, and algae with high antioxidative potential. Astaxanthin is a lipid-soluble carotenoid that can easily cross through the cellular membrane layers to catch the reactive oxygen metabolites. Astaxanthin also has pigmentation properties making it suitable for pharmaceutical, cosmetic, nutraceutical, agriculture, and aquaculture sectors. Recently, astaxanthin is suggested as a natural scavenger for free radicals induced by COVID-19. Besides, using astaxanthin as antioxidative and immunostimulant agents is well-reported in several clinical studies. The output of these investigations should be simplified and presented to the scientific community to utilize the available information and fill the gap of knowledge. Also, it is necessary to update the researchers with the recent recommendations of applying astaxanthin in vivo and in vitro to help in proposing new horizons for engaging natural antioxidative agents to protect human and animal health. Herein, this review article tackled the nature, sources, potential roles, applicable sides, and availability of astaxanthin to fortify the scientific community with the required knowledge for further research efforts.

Antagonistic Potential Marine Bacteria Against Luminescent Vibriosis Pathogen Vibrio Harveyi Obtained from Shrimp Farm, Marakkanam, Tamil Nadu, India

Aquaculture farming practices in India and other countries are facing a lot of economic loss due to luminescent vibriosis.Ecological and cost-effective practices may have been warranted to combat this tricky disease. A total of 57 morphologicallydifferent marine bacterial isolates were isolated from samples collected at different aquaculture ponds in Marakkanam, Tamil Nadu,India and screened for their antibacterial potential against luminescent vibriosis causing bacteria Vibrio harveyi. All marine bacterialisolates were screened for antibacterial activity by cross streak method against two different isolates V. harveyi GNC01 and V.harveyi GNC03. Secondary screening of antagonistic isolates by dual culture plate method and agar well diffusion method leads tothe identification of antagonistic isolates. The antagonistic isolates were characterized by molecular taxonomy (16S rRNA genesequence) and phylogeny and identified as Neobacillus niacini (GNC04), Bacillus halotolerans (GNC06), Bacillus amyloliquefaciens(GNC16), Lacticaseibacillus paracasei (GNC23) and Lactiplantibacillus plantarum (GNC24). The minimum inhibitory concentrationof all these selected bacterial crude secondary metabolites against both Vibrio harveyi isolates GNC01 and GNC03 ranged between0.062 to 0.50 mg/mL. The GC-MS profiling of the ethyl acetate extract revealed the presence of antibacterial compounds such asOxime-,methoxy-phenyl (26.63%), 2,3-Dihydroxybutane (9.52%), Phosphite, menthyldimethyl- (2.83%), Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl)- (2.07%). The results of this study suggest that Lactiplantibacillus plantarum (GNC24) is apotential source for antagonistic secondary metabolites against luminescent vibriosis causing bacteria Vibrio harveyi. Further,biological control formulation with these isolates and their metabolites will be a reward for the integrated pest management inthe aquaculture sector.

The changing role and definitions of aquaculture for environmental purposes

AbstractAquaculture is the fastest growing form of food production across the globe. The expansion of the industry has brought about a diversity of approaches to mitigate social and ecological impacts associated with aquaculture production systems. At the same time, there is a growing interest in utilizing aquaculture for conservation purposes including species recovery, habitat restoration and offsetting the impacts of wild capture on vulnerable harvested species. The diversification of the aquaculture sector and the overlapping use of terminology to describe alternative aquaculture approaches can create challenges for policy makers, managers and industry practitioners. Clear distinction between alternative aquaculture approaches and intent may improve regulatory, permitting, monitoring and consumer awareness outcomes. Here, we examine the use of four primary aquaculture approaches in the scientific literature: ‘commercial aquaculture’, ‘conservation aquaculture’, ‘restorative aquaculture’ and ‘regenerative aquaculture’ to elucidate the similarities and differences and improve understanding of the approaches. We propose definitions for the terms based on empirical analysis of related words used in scientific texts and fitness into a particular initiative. In addition, we discuss the use of those terms within the context of benefits to ‘people and nature’, namely activities that include economic, social and environmental outcomes and the variability therein. Clear definition of terms and related activities in a burgeoning field can minimize semantic confusion while improving opportunities to craft robust policy guidelines and improve stakeholder understanding and practice of aquaculture activities.

Prospects of Implementation of Blockchain Technology into Aquaculture Sector of Ukraine

Introduction. The development of fish farming in aquaculture in a sustainable way ensures the sustainability of fisheries, which is associated with local problems in each region. Ukraine’s fish production has been falling sharply over the last 30 years, and in 2021 the decline was more than 87 percent in comparison with 1990. In the Ukrainian aquaculture sector, there is a high degree of bureaucracy and risks of corruption, which need to be addressed in order to find a solution for the economy and businessmen. World reports show that Ukraine is among the world's leaders in illegal fishing. Thus, it is highly necessary to implement technologies for sector traceability and transparency, i.e., blockchain.&#x0D; Aim and tasks. The main aim of this article is to research the possible mechanism of implementation of the transparent and efficient system of using the aquatic bioresources of Ukraine. A secondary aim would be to actualize the information regarding the use of blockchain technology in the aquaculture sector.&#x0D; Results. This research shows that Ukraine’s aquacultural sector is going through a crisis, which is being induced by the high level of corruption and poaching. The digitization of the aquaculture supply chain powered by blockchain technology has been proposed. The role of blockchain technologies is revealed through functions such as evidence, tamper-proof, transparency, and decentralization. It was investigated the positive impact of blockchain technology on aquaculture business, such as reduction in bureaucracy, quality assurance, improvement in information exchange, low cost of transactions, improvement in audit performance, easy recall process, product origin verification, and low probability of fraudulent activity. It would greatly reduce the time needed to gather all the documentation essential for work and reporting. The blockchain implementation roadmap has been developed, including the following stages: concept, legislation compliance, limited prototype, final vision, further research and optimization.&#x0D; Conclusions. Blockchain technology fits Ukraine’s economic goals in the long term perspective, such as continued digitalization of the country. Due to the blockchain technology, products of aquaculture would not enter the market unless registered in the unified system. That will influence the reduction of "informal economy" in the sector and the increase of market mechanisms. It will also have a positive influence on food security for the population and economic security for the producers. It will be a precedent for a fully transparent and digitalized field of economy.

Simple processing technology for the production of consumption salt in Indonesia

As an archipelagic country, Indonesia has a concentrated deposit of salt in Java and Madura Island. Furthermore, the total demand for the mineral in 2017, 2018, and 2019 were 3.9, 4, and 4.2 million tons, respectively. This study was carried out in 4 stages, namely identification of raw materials, crystallization, mechanical, and re-crystallization. The salt crystallization and purification process is beneficial to the aquaculture, fishery, and health sectors. The results showed that the raw materials obtained from the coastal areas of East Java and Bali Island have an average NaCl interval estimation range of 80.31% to 92.37%, which indicates that they are suitable for salt production. The product obtained from the processes have the potential to initiate diversification of business development in the country with an estimation range of 95.38% to 97.25%.

Technical efficiency analysis of shrimp farms in Andhra Pradesh, India using stochastic frontier approach

Brackishwater aquaculture sector is dominated by the exotic vannamei shrimp farming, which is the economic engine of Indian aquaculture. In 2019-20, exports of 12,89,651 t of Indian marine products fetched foreign exchange worth ₹46,662.85 crores and farmed shrimps accounted for about two-thirds of the shrimps exported. Shrimp farming is export oriented and market price often fluctuates widely impacting the profitability significantly. We conducted this study to estimate technical efficiency of the shrimp farmers In Nellore District, Andhra Pradesh State which tops in shrimp aquaculture in the country. The data were collected through structured questionnaire using personal interview from 80 farmers during COVID 2020 pandemic period. The farm specific technical efficiency varied from 75 to 94% with a mean of 93%. The estimates of the discrepancy parameter γ indicated that 93% of the difference between the maximum possible output and actual output were due to differences in technical inefficiencies of farmers Feed and labour are the significant variables compared to other variables. The results indicated that farmers need to be encouraged to apply more feed to increase shrimp production. Keywords: Stochastic production frontier, Sustainability, Technical efficiency, Vannamei shrimp aquaculture