Fish Farming Research Articles

Farmed fish welfare research status in Latin America: A review.

Latin America (LATAM) plays an important role in the world's production of aquatic animals and is the second most productive region in the world. Chile, Ecuador, Brazil, Mexico, Colombia, and Perú contribute 87% of LATAM aquaculture production. The fish welfare in aquaculture is of increasing public concern globally, and LATAM is no exception, growing in importance for fish farmers, authorities, and scientists. Although the topic is somewhat controversial, the welfare status of farmed fish has direct implications for their production and the sustainability of the industry. Therefore, this study analyses scientific papers on animal welfare in farmed fish, from the six countries in LATAM with the highest aquaculture production. The main objectives were to quantify the number of papers published between 2000 and 2023 on fish welfare by using scientific databases. A total of 285 papers were found for the period analysed. The country with the largest number of publications was Brazil (75.79%), followed by Chile (13.33%), Mexico (7.02%), Peru (1.75%), Ecuador, and Colombia (1.05%). Nile tilapia was the most studied species, appearing in 30.18% of the publications, with most of the studies mainly dealing with nutrition (32.28%). The growth of aquaculture is leading to joint efforts to generate knowledge on welfare issues, especially in poorly studied species with high production, to create policies that help minimize welfare risks. Given this, the insights generated by this review could be a useful addition to approaches investigating the trends and concepts of fish welfare in LATAM.

Immunoprotective efficacy of aqueous monovalent vaccine, turmeric (curcuma longa) rhizome and soursop (annona muricata) leaves against Pseudomonas aeruginosa infection in African sharptooth catfish (clarias gariepinus) fingerlings

ABSTRACT This study evaluated the efficacy of aqueous monovalent vaccine (AqMV) and adjuvant monovalent vaccine (AdMV), different levels of soursop leaves (SL), and turmeric rhizome (TR) on growth performance, immune response, and disease resistance of African sharptooth catfish (Clarias gariepinus) fingerlings against Pseudomonas aeruginosa. The experimental diet consists of control (without vaccine, soursop leaves and turmeric rhizome), AqMV2, AdMV3, TR4 (0.5), TR5 (1.0), TR6 (2.0), SL7 (0.5), SL8 (1.0) and SL9 (2.0). Fish were exposed to 4.85 log10 CFU/ml P. aeruginosa of 24 h old culture intraperitoneally after feeding trial with relative level of protection recorded at 28 days of post-infection. The results revealed that fish fed with treated diets showed increased (p < .05) weight gain, feed conversion ratio, nitrogen metabolism, white blood cell, globulin, total protein and blood performance and better relative level of protection compared to the control. The microbial loads in fish samples (muscle, spleen and kidney) were reduced (p < .05) in the treatments when compared to the control at 4-week post-infection. These results suggest that inactivated aqueous monovalent vaccine, soursop leaves and turmeric rhizome could be effective against P. aeruginosa infection in fish farming.

Comparative safety and efficacy of autogenous vaccine administrated by different routes against furunculosis caused by Aeromonas salmonicida sub. salmonicida in large Rainbow trout (Oncorhynchus mykiss)

The development and growth of fish farming are hindered by viral and bacterial infectious diseases, which necessitate effective disease control measures. Furunculosis, primarily caused by Aeromonas salmonicida, stands out as a significant bacterial disease affecting salmonid fish farms, particularly rainbow trout. Vaccination has emerged as a crucial tool in combating this disease. The objective of this experiment was to assess and compare the efficacy and duration of different vaccine protocols against furunculosis in large trout under controlled rearing conditions, utilizing single and booster administrations via intraperitoneal, oral, and immersion routes. Among the various vaccination protocols tested, only those involving intraperitoneal injection, administered at least once, proved truly effective in preventing the expression of clinical signs of furunculosis and reducing mortality rates. A single intraperitoneal administration provided protection for up to 2352°-days, equivalent to approximately 5 months in water at 16 °C. However, intraperitoneal vaccination may lead to reduced growth in the fish due to resultant intraperitoneal adhesions. Additionally, protocols incorporating booster doses via intraperitoneal injection demonstrated efficacy regardless of the administration route of the primary vaccination. Nevertheless, the use of booster vaccinations via the intraperitoneal route did not confer any significant advantage over a single intraperitoneal injection in terms of efficacy.

Mapping the Future: Revealing Habitat Preferences and Patterns of the Endangered Chilean Dolphin in Seno Skyring, Patagonia.

Species distribution modeling helps understand how environmental factors influence species distribution, creating profiles to predict presence in unexplored areas and assess ecological impacts. This study examined the habitat use and population ecology of the Chilean dolphin in Seno Skyring, Chilean Patagonia. We used three models-random forest (RF), generalized linear model (GLM), and artificial neural network (ANN)-to predict dolphin distribution based on environmental and biotic data like water temperature, salinity, and fish farm density. Our research has determined that the RF model is the most precise tool for predicting the habitat preferences of Chilean dolphins. The results indicate that these dolphins are primarily located within six kilometers of the coast, strongly correlating with areas featuring numerous fish farms, sheltered waters close to the shore with river inputs, and shallow productive zones. This suggests a potential association between dolphin presence and fish-farming activities. These findings can guide targeted conservation measures, such as regulating fish-farming practices and protecting vital coastal areas to improve the survival prospects of the Chilean dolphin. Given the extensive fish-farming industry in Chile, this research highlights the need for greater knowledge and comprehensive conservation efforts to ensure the species' long-term survival. By understanding and mitigating the impacts of fish farming and other human activities, we can better protect the habitat and well-being of Chilean dolphins.

Antimicrobial use, residues and resistance in fish production in Africa: systematic review and meta-analysis

In low- and middle-income countries, data on antimicrobial use (AMU) and antimicrobial resistance (AMR) in aquaculture are scarce. Therefore, summarizing documented data on AMU, antimicrobial residue (AR), and AMR in aquaculture in Africa is key to understanding the risk to public health. Google Scholar, PubMed, African Journals online, and Medline were searched for articles published in English and French following the PRISMA guidelines. A structured search string was used with strict inclusion and exclusion criteria to retrieve and screen the articles. The pooled prevalence and 95% confidence intervals were calculated for each pathogen–antimicrobial pair using random effects models. Among the 113 full-text articles reviewed, 41 met the eligibility criteria. The majority of the articles reported AMR (35; 85.4%), while a few were on AMU (3; 7.3%) and AR (3; 7.3%) in fish. The articles originated from West Africa (23; 56.1%), North Africa (8; 19.7%), and East Africa (7; 17.1%). Concerning the antimicrobial agents used in fish farming, tetracycline was the most common antimicrobial class used, which justified the high prevalence of residues (up to 56.7%) observed in fish. For AMR, a total of 69 antimicrobial agents were tested against 24 types of bacteria isolated. Bacteria were resistant to all classes of antimicrobial agents and exhibited high levels of multidrug resistance. Escherichia coli, Salmonella spp., and Staphylococcus spp. were reported in 16, 10, and 8 studies, respectively, with multidrug resistance rates of 43.1% [95% CI (32.0–55.0)], 40.3% [95% CI (24.1–58.1)] and 31.3% [95% CI (17.5–49.4)], respectively. This review highlights the high multidrug resistance rate of bacteria from aquaculture to commonly used antimicrobial agents, such as tetracycline, ampicillin, cotrimoxazole, gentamicin, and amoxicillin, in Africa. These findings also highlighted the lack of data on AMU and residue in the aquaculture sector, and additional efforts should be made to fill these gaps and mitigate the burden of AMR on public health in Africa.

Dynamics of Saltwater Intrusion in a Heterogeneous Coastal Environment: Experimental, DC Resistivity, and Numerical Modeling Approaches

Saltwater intrusion (SWI) is a critical concern affecting coastal groundwater sources due to natural and anthropogenic activities. The health of coastal aquifers is deteriorated by excessive SWI, mainly caused by the disturbance of the freshwater–saltwater equilibrium due to the escalating population, climate change, and the rising demand for freshwater resources for human activities. Therefore, gaining insight into the dynamics of SWI is crucial, particularly concerning the various factors that influence the intrusion mechanism. The present study focuses on the experimental simulation of saltwater in freshwater aquifers, considering boundary conditions and density-dependent effects. Two geological scenarios within coastal environments were investigated: First, a uniform, homogeneous case consisting of only sand, and second, a heterogeneous case in which layers of sand, clay, and sand mixed with pebbles are used. During the experiment, DC resistivity sounding data, as part of a widely recognized geophysical method, were collected and subsequently inverted to determine the depth of the freshwater–saltwater interface (FSWI). A finite element analysis was employed to generate numerical models based on experimental feedback. Further, for validation purposes, electrical resistivity tomography (ERT) data were collected from two distinct locations: near the seacoast and an aquaculture area. The ERT results show the presence of salinity intrusion in the study area, attributed mainly to groundwater overpumping and fish farming practices. The experimental findings indicate that the advancement of saltwater is affected by the geological properties of the media they traverse. The porosity (ϕ) and permeability (k) of the geological layer play a crucial role during the passage of saltwater flux into freshwater aquifers. The FSWI deviated along the clay boundary and hindered the easy passage of saltwater into surrounding layers. The alignment of experimental, numerical, and geophysical data suggests that this integrated approach could be valuable for studying SWI and can be applied in different geological settings, including tidal flats and alluvial plains.

Metabolomics analysis of splenectomy of Nile tilapia (Oreochromis niloticus) reveals the spleen involved in regulating liver lipids and amino acids metabolism

The liver is essential for nutritional balance in fish, and liver damage in farmed fish often arises from factors like overfeeding, causing various health issues. Clinical observations indicate that liver diseases frequently involve spleen dysfunction, and there is evidence to suggest that the spleen has a significant impact on liver function. However, there has been no discussion on the role of the spleen in maintaining liver health in fish. To understand the role of fish spleen in liver metabolism, this study selected Nile tilapia (Oreochromis niloticus) as the experimental material and first established a tilapia splenectomy model. Various biochemical parameters of the liver and serum were measured, and the liver metabolism characteristics of the splenectomy group (SP group) and the sham operation group (SO group) were analyzed using metabolomics. After splenectomy, biochemical parameters of the liver and serum showed abnormalities, including significant increases in total cholesterol (T-CHO) and serum total bile acid (TBA) levels, alongside a significant decrease in liver TBA levels, suggesting impaired metabolic function and cholesterol deposition in the liver. Metabolomics analysis showed that metabolites such as lipids, lipid-like molecules, and organic acids and derivatives were differentially regulated between the SO and SP group. KEGG analysis showed that differential metabolites were enriched in lipid metabolism and amino acid metabolism. The metabolic pathway analysis of differential metabolites showed that after splenectomy, the low-activity urea cycle in the liver may accelerate lipid synthesis, while low concentrations of aromatic amino acids and taurine may inhibit lipid catabolism. These results indicate that after splenectomy, the liver metabolic capacity is impaired, which causes abnormal lipid metabolism by interfering with amino acid metabolism, making splenectomy tilapia liver at risk of liver disease, including cholesterol deposition, hepatic steatosis and nonalcoholic fatty liver disease (NAFLD). Our results show that the spleen is involved in regulating liver lipid and amino acid metabolism, and the spleen may interfere with lipid metabolism by regulating liver amino acid metabolism. Our data can provide support for further research on liver and spleen functions and the immune-nutrient metabolism mechanisms in fish, as well as new ideas for healthy fish farming.

The impact of small scale fish farming on poverty reduction in South-East Zone of Nigeria

Over the years, successive administrations in Nigeria have embarked on numerous poverty reduction programmes aimed at reducing the poverty rate in Nigeria. These efforts have not yielded much result as poverty rate has continued to soar and pervade every geo-political zone in Nigeria. The poverty situation, coupled with the low uptake of fish farming technology in the south-east zone has prompted the need to examine the impact of small-scale fish farming on poverty reduction in the south-east zone of Nigeria. The dependent variable of the study is poverty reduction, which has household expenditure as its proxy. The independent variable is small-scale fish farming, proxy by income, employment, food security and consumption multiplier. Data collection was made through in-depth Interview (IDI) guide, while analysis was done using thematic analysis technique. A total of 40 participants, comprising of 30 fish-farm owners and 10 employees were selected purposively from the states of Anambra, Ebonyi and Imo for the interview. The study findings suggest that small-scale fish farmingin the study area impacts positively on poverty reduction, as increase in each of the independent variables tends to increase the dependent variable. The study recommended the establishment of fish farm settlements; granting of credit facilities to fish farmers; establishment of skill acquisition and training centers for farm employees; and improvement electricity supply and road network for lower energy cost and easy transportation of fish products. Keywords: Fish Farming, Small-Scale, Poverty Reduction.

Forecasting ocean hypoxia in salmonid fish farms

IntroductionHypoxia is defined as a critically low-oxygen condition of water, which, if prolonged, can be harmful to fish and many other aquatic species. In the context of ocean salmon fish farming, early detection of hypoxia events is critical for farm managers to mitigate these events to reduce fish stress, however in complex natural systems accurate forecasting tools are limited. The goal of this research is to use a machine learning approach to forecast oxygen concentration and predict hypoxia events in marine net-pen salmon farms.MethodsThe developed model is based on gradient boosting and works in two stages. First, we apply auto-regression to build a forecasting model that predicts oxygen concentration levels within a cage. We take a global forecasting approach by building a model using the historical data provided by sensors at several marine fish farms located in eastern Canada. Then, the forecasts are transformed into binary probabilities that indicate the likelihood of a low-oxygen event. We leverage the cumulative distribution function to compute these probabilities.Results and discussionWe tested our model in a case study that included several cages across 14 fish farms. The experiments suggest that the model can detect future hypoxic events with a commercially acceptable false alarm rate. The resulting probabilistic predictions and oxygen concentration forecasts can help salmon farmers to prioritize resources, and reduce harm to crops.

Evaluation of Genotoxicity by Comet Assay in Tissues of Clarias gariepinus Exposed to Cassava Effluent

Untreated wastewater discharge into waterbodies poses a number of risks, including the potential for aquatic organisms' DNA to be damaged. Using the comet assay, this study assessed the genotoxic impact of cassava wastewater on the gonads, liver, and gills of post-juvenile Clarias gariepinus. The post-juvenile C. gariepinus fish were acquired from a fish farm in Edo State, Nigeria, and were subjected to different concentrations of cassava wastewater (0.2%, 0.3%, 0.5%, and 0.7%) for a duration of 96 hours. In contrast to the typical actions seen in the control groups, the fish exposed to the effluent exhibited restless, erratic movements, and gasping for air. The first set of repetitions showed that catfish mortality increased with concentration; after 96 hours, exposure to the lowest concentration (0.2%) and the highest concentration (0.7%) of cassava wastewater caused 10% and 40% of the fish to die, respectively. The second set of repetitions showed that catfish mortality increased with increasing concentration; after 96 hours, exposure to the lowest concentration (0.2%) and the highest concentration (0.7%) of cassava wastewater resulted in 20% and 50% catfish mortality, respectively. Following the exposure time, the fish were brought to the lab where their gonads, liver, and gills were removed in order to use the comet assay for genotoxic assessment. The genotoxins present in the wastewater can be the reason for the DNA impairment found in the genotoxic assessment result at different effluent concentrations. The investigation also showed that DNA damage increased with increasing concentration, indicating a dose-dependent genotoxic effect of cassava wastewater on post-juveniles of C. gariepinus. This research demonstrates the critical importance of treating wastewater before to discharge.

Presence and antimicrobial susceptibility profile of Salmonella spp. isolated from fish farms

Salmonella spp. are important foodborne pathogens often associated with infectious outbreaks caused by consuming contaminated food. Although these microorganisms are widely distributed in several animal production chains, there are few records of their occurrence in aquaculture. This study aimed to evaluate the presence and antimicrobial resistance of Salmonella spp. isolated from fish farms. Samples were collected from three fish farms, covering water, fish, and epilithic biofilm. Salmonella isolates were identified by PCR, and serotyping was performed using the slide agglutination method, according to the Kaufman-White system. Susceptibility to antimicrobial agents was assessed using the Kirby and Bauer disk diffusion method. The presence of class 1 and 2 integrons was determined by PCR. Ninety samples were examined, of which 13 (14.44%) were positive for S. enterica, of which 5 strains were isolated from lagoon water, 3 from fish, and 5 from epilithic biofilm. Among the samples, the serotypes S. Minnesota, S. Panamá, and S. Anatum were identified. Antimicrobial resistance rates were highest for sulfonamides (92.30%), trimethoprim (84.61%), tetracycline (46.15%), and streptomycin (46.15%). Multiple antibiotic resistance was confirmed in 84.61% of the isolates, with 100% presenting integron class 1 and 7.69% integron class 2. This study demonstrated a high prevalence of multiresistant bacteria in fish farms, which reinforces public health concerns due to the use of antibiotics and the risk associated with food from farmed freshwater fish. Given these results, the need for new external research into control and prevention strategies for Salmonella spp. is evident. in aquaculture, as well as greater regulation in fish production chains.

A Fuzzy-Based Approach for Flexible Modeling and Management of Freshwater Fish Farming

Most populated developing countries having water resources, like Egypt, are interested in aquaculture since it supplies around 30% of the cheap protein consumed by customers. Increasing the production of aquaculture, specifically fish farming, in such countries represents an essential need. One candidate water resource for freshwater fish farming in Egypt is the Nile River (1530 km long). Yet, this represents a challenging task due to the existing variations in its water quality (WQ) parameters, such as dissolved oxygen, acidity, and temperature, at different sites. Climate change and pollution negatively affect many water quality parameters. This work provides a fuzzy-based approach for modeling WQ requirements for a set of fish types and evaluates the suitability of a water site for farming them. Thus, it greatly helps managing and planning fish farming in a set of water sites. It benefits from the flexibility of fuzzy logic to model the farming requirements of each fish type. Consequently, it evaluates and clusters the water sites with respect to their degrees of suitability for farming various fish types. The illustrative case study considers 27 freshwater sites spread along the Nile River and 17 freshwater fish types. The result incorporates a set of suitable clusters and a set of unsuitable ones for farming each fish type. It greatly helps managing and planning fish farming, to maximize the overall productivity and prevent probable catastrophic damage. In addition, it shows how to enhance each unsuitable site. We believe that eliminating the causes of pollution in the polluted freshwater sites along a water source could cause a significant boom in the cultivation of multiple freshwater fish types.

Method for layout optimization of coastal cage aquaculture systems in Southeast Asia

This paper presents the development of a generally applicable method for the layout optimization of coastal cage aquaculture systems in Southeast Asia. The method combines data from the authors’ spatial-planning methodology with results of water quality modelling and an optimization technique based on genetic algorithms. This study successfully demonstrates the method's effectiveness for a target aquaculture site in northwest Bali, Indonesia. Optimum siting and sizes of fish farms to maximize fish production and promote fish growth while securing environmental sustainability are delivered for the site in Bali. The results of the application for several fish farming sizes show that by proper fish farming layout, environmentally sustainable fish production on the western channel of the site in Bali could rise tremendously with respect to the current operating conditions. Fish farm clusters with 256 cages are found to be best suited to the western channel. The method has broad applicability, can be upscaled to new sites, and can be used to assess, expand, and optimize currently operating sites.

Dynamics of the configuration of the fish farming economic activity in Colombia

El presente artículo analiza el fenómeno de surgimiento de un conjunto de organizaciones (empresas) en un espacio y tiempo específico, generando una nueva actividad económica. Se trata del caso de las empresas conformadas en torno a la actividad piscícola con las cuales se estableció una novedosa dinámica económica en una región periférica de lento desarrollo económico, ubicada al sur de Colombia. El estudio fue de carácter cualitativo de tipo documental inventariando fuentes primarias y secundarias con las cuales fue reconstruida la trayectoria de la actividad piscícola en Colombia y el departamento del Huila. Como conclusión se puede afirmar que el surgimiento de la piscicultura se da por el concurso de una política de fomento a la explotación piscícola adelantada por el Estado, instituciones públicas y gremiales del sector agropecuario; la existencia de un marco regulatorio que permitió la actuación de organizaciones dedicadas a la actividad; los aportes tecnológicos y científicos divulgados por entidades multilaterales y entidades públicas descentralizadas que impulsaron mejoramientos genéticos y alimenticios; y el deterioro de la pesca tradicional continental que permitió una demanda orientada hacia productos piscícolas.

Factors Affecting the Performance of Fisheries Extension Workers in Improving the Class of Fish Farming Groups in East Java

Factors Affecting the Performance of Fisheries Extension Workers in Improving the Class of Fish Farming Groups in East Java

Implementing Zonal Aquaculture Innovation Platforms in Uganda: Key Lessons Learned

Uganda’s aquaculture sub-sector is rapidly developing, contributing up to 22% of all fish produced in the country. However, the sub-sector still faces challenges related to limited access to extension services, production inputs, post-harvest handling facilities, disease incidences, value-addition skills and weak market linkages. Although there have been isolated interventions at different aquaculture value-chain nodes, the registered challenges continue to recur. To address prioritized issues in Uganda’s aquaculture sub-sector, nine zonal aquaculture innovation platforms were established based on the country’s nine agro-ecological zones. These platforms brought together different stakeholders to identify solutions to common problems in each aquaculture value-chain node. Each innovation platform consisted of fish farmers, hatchery operators, traders, extension workers, researchers, input dealers, local leaders, and financial institutions. During a series of zonal workshops, participants identified constraints to the aquaculture sub-sector in their respective zones. From the findings, there are technical knowledge gaps across the entire aquaculture value chain mainly affecting hatchery operators, input suppliers, and farmers. Therefore, there is need for coordinated interventions to enhance access to production technologies, innovations, knowledge, and skill transfer to promote gender-centered aquaculture development.

Overview on the role of dietary Spirulina platensis on immune responses against Edwardsiellosis among Oreochromis niloticus fish farms

Edwardsiellosis is a bacterial fish disease that mostly occurs in freshwater farms and is characterized by a high mortality rate. Edwardsiella tarda strain was recovered from 17 fish out of 50 Nile tilapia, which were harboring clinical signs of systemic septicemia. The level of un-ionized ammonia (NH3) in the fish farm’s water was 0.11–0.15 mg/L, which was stressful for the Nile tilapia.Sequencing of the gyrB1 gene confirmed that the isolate was E. tarda JALO4, and it was submitted to NCBI under the accession number PP449014. The isolated E. tarda harbored the virulence gene edw1 AHL-synthase (quorum sensing). In addition, the isolate was sensitive to trimethoprim and sulfamethoxazole mean while it was intermediate to florfenicol. The median lethal dose (LD50) of E. tarda JALO4 was determined to be 1.7 × 105 CFU/mL in Nile tilapia.In the indoor experiment, Nile tilapia (45.05 ± 0.4 g), which received dietary Spirulina platensis (5 and 10 g/kg fish feed), showed optimum growth and feed utilization. Meanwhile, after receiving dietary S. platensis, the fish’s feed conversion ratio (FCR) was significantly enhanced compared to the control, which was 1.94, 1.99, and 2.88, respectively. The expression of immune-related genes interleukin (IL)-1β and tumor necrosis factor (TNF)-α were upsurged in E. tarda-challenged fish with higher intensity in S. platensis groups. Dietary S. platensis at a dose of 10 g/kg fish feed could provide a relative protection level (RPL) of 22.2% Nile tilapia challenged against E. tarda. Nile tilapia experimentally infected E. tarda, drastically altering their behavior: higher operculum movement, low food apprehension, and abnormal swimming dietary S. platensis (10 g/kg fish feed) could rapidly restore normal status.It was concluded that Edwardsiellosis could alter Nile tilapia behavior with a high loss in fish population. Fish received dietary-S. platensis could rapidly restore normal behavior after E. tarda infection. It is recommended the incorporation of S. platensis at doses of 10 g/kg into the Nile tilapia diet to boost their immunity and counteract E. tarda infection.

Socio-environmental and economic impacts due to the disaster at Vale S.A. in Brumadinho, MG, Brazil: A systematic review

Significant socio-environmental and economic impacts on fishermen and fish farmers in the Três Marias reservoir arose from the collapse of the mining tailings dam in the municipality of Brumadinho, MG, Brazil, in 2019. To help assess this situation, we carried out a systematic review to find information that scientifically documents these impacts. To this end, we used the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Journal Portal, accessed through the Federated Academic Community, to search for data indexed between 2019 and 2023, in the following databases: Web of Science, Scopus, and CAB Direct. We used Brumadinho as the central keyword and linked to it 25 other secondary keywords, such as environmental disaster, fishermen, fish farmers, and Três Marias dam. To screen and select the results, we used Rayyan software and the Preferred Reporting Items for Systematic reviews and Meta-Analyses methodology. The search resulted in 990 articles, 61 theses, and 251 dissertations. Among them, only 26 articles, 19 theses and 66 dissertations were eligible as contributions to the topic, but very few reported the situation of fishermen and fish farmers. We concluded that there is a lack of information on the damage suffered by these people, and that more scientific studies and attention to this public are needed.

Re-Circulatory Aquaculture Systems: A Pathway to Sustainable Fish Farming

Recirculating Aquaculture Systems (RAS) represent a transformative approach to sustainable fish farming that offers a viable solution to meet the growing global demand for seafood while minimizing environmental impact. These closed-loop systems recirculate and reuse water, reducing water consumption by up to 99% compared to traditional aquaculture methods. RAS also mitigate the risk of disease transmission, escapement, and pollution by isolating farmed fish from natural populations and the surrounding environment. Technologically advanced RAS employ mechanical filtration, biological filtration, and disinfection processes to maintain optimal water quality for fish growth. This high level of control allows for the farming of a wide range of species, including predatory finfish, in locations far from coastal areas. Furthermore, the integration of aquaponics in RAS enables the production of high-quality vegetables and herbs using the nutrient-rich wastewater, creating a sustainable closed-loop system. Despite the higher initial investment required, RAS have demonstrated consistent profitability and the potential for significant returns. By promoting "in-sourcing" and creating local jobs, RAS can contribute to the economic development of communities while reducing the carbon footprint associated with international seafood trade. As the aquaculture industry continues to evolve, RAS are poised to play a crucial role in ensuring the long-term sustainability of fish farming. By combining technological advancements with environmental stewardship, RAS offer a promising pathway towards meeting the world's growing demand for seafood while preserving the health of our aquatic ecosystems.

Inclement Entrepreneurial Gaps in Community Wildlife Management Business Model: A Case of Mbarang’andu and Tunduru Wmas in Southern Tanzania

Purpose: This study examined entrepreneurial gaps in Mbarang’andu and Tunduru Wildlife Management Areas (WMAs) since their establishment during the 5 years of business plan operations and implications thereafter. Design/Methodology/Approach: The population of this study was five WMAs that formed the cases for the study, and for the case of WMA leaders, the population was 40 leaders. The sample size for the WMAs selected as the cases for the study were two (2), Tunduru and Mbarang’andu purposefully selected. Further, the sample size for WMA leaders was 20 (50% of the population) purposefully selected. Descriptive analysis was used to summarise demographic and revenue data, and a Pearson Chi-square test was performed on the demographic data. A paired samples T-test was used to compare the required business start-up and available funds to reveal the equity gap in the two WMAs and compare the level of implementation of planned business activities in the two WMAs. Research Limitation: The research was limited to two WMAs and a small sample size since the client determined its size, given that this paper emanated from the consultancy project. Findings: Findings indicate that both WMAs have a high potential for carbon trading, photographic tourism, beekeeping, fish farming, and heritage tourism. The difference in the required funding and available funds for various expenditures in business start-ups was found to be statistically significant in both WMAs. The difference in the level of implementation of planned business activities was also found to be statistically significant in the two WMAs. Practical implications: To bridge the entrepreneurial gaps in the WMAs, proactive fundraising, diversification of income-generating activities, including carbon trading, human resource capacity building, and appropriate marketing of tourism and nature-based products are needed. Social Implications: The results of this research will form the basis for bridging entrepreneurial gaps in the WMAs, hence fueling optimal exploitation of entrepreneurial opportunities in wildlife that benefit the community at large in return. Originality: This paper is original; only some extracts were used in the conference proceedings for the University of Dodoma (UDOM) 2019. Its novelty is inclined to expose entrepreneurial gaps and the framework for bridging such gaps in wildlife businesses.