CONTEXT: Aquaculture has surpassed capture fisheries in terms of production and is among the fastest growing food sectors. It has great potential to contribute to food security and nutrition, poverty reduction, jobs, and environmental sustainability. Fish seed is increasingly considered to be a major driver and disabler of aqua-culture development. However, little is known about how fish seed systems operate, their challenges and opportunities, or entry points for strengthening them. OBJECTIVE: This study analyzes primary data on the challenges and opportunities faced by various actors along the fish seed chain, documents the lessons from a fish seed project (Ghana Tilapia Seed Project, 2019-2022), and provides an analysis of entry points for strengthening fish seed systems. METHODS: Using an analytical framework that tracks germplasm base, seed production and quality, seed availability and distribution, and the information flow along the fish seed value chain, we analyze the case of Ghana, the top producer of farmed tilapia in sub-Saharan Africa. The study uses a mixed-methods approach, including value chain analysis, action-oriented research methods, and statistical analysis of survey data. RESULTS AND CONCLUSIONS: Findings indicate that the initial rapid growth in tilapia production in Ghana was partly due to an improved local strain released in 2004; however, the recent stagnation is largely caused by seed-related issues (poor maintenance and improvement of germplasm base, seed quality and availability, lack of information and coordination, and lack of enforcement of regulations). This study highlights the successes and lessons learned from the Ghana Tilapia Seed Project on broodstock distribution, training on fingerling production, establishment of nurseries, and training of fish farmers. The lessons highlight the need for policy changes and capacity building related to strain development and broodstock management. SIGNIFICANCE: These findings fill the large gap in evidence on the functioning of fish seed systems and how to strengthen them. They can directly inform ongoing country-level efforts and programs aiming to develop aquaculture.

After five years of impoundment, Bui Reservoir fisheries has evolved with silver catfish, Chrysichthys nigrodigitatus among the most important commercial species. Based on standard length analyses of 162 individuals (62 males, 39 females) from post-impoundment seasonal sampling at three (3) stations, the population structure, well-being, growth type, sex ratio, length at first capture and rates of growth, mortality, exploitation, and other derived parameters of C. nigrodigitatus were estimated to provide requisite information for sustainable management. The population is composed of fewer juveniles and more males than females, with females relatively larger than males (modal size 7.0–7.9 for males and 9.0–9.9 for females). Females were physiologically better than males (79.49% of females had condition factor above 2.0 compared to 53.23% males) notwithstanding seasonal fluctuations. Unimodal length structure was observed for all seasons except for the post-rainy season with 2 modes, all of which, however, indicated a single year class and single spawning. Estimated hypoallometric and hyperallometric growth values among seasons and sexes were not significantly different from the isometric pattern. Estimated von Bertalanffy growth parameters were asymptotic size ( L ∞ ) = 13.07 cm SL, growth constant ( K ) = 1.01 year, −1 and length at time 0 ( t o ) = 0.18. Growth performance index ( ϕ ') was 2.27, indicating slow growth while the lifespan was 2.73 years. Total mortality, natural mortality, and fishing mortality estimates were high (3.56, 2.44 and 1.12 respectively) while exploitation was below optimum ( E  = 0.32). Regular assessment of fish population, growth, and other characteristics is recommended to provide requisite information for strategic interventions for sustainable management and development of reservoir fisheries.

Despite recent surge in microplastics (MPs) research, there is a paucity of information on freshwaters in Ghana. For the first time, MPs in cage and wild sites of the lower Volta Basin were evaluated, and polymer type characterized using LDIR and ATR-FTIR. Seasonal variations and mode of fish production significantly influenced MPs abundance. In fish, MPs concentration of 387 ± 33.85 (wet season) contrasted with 288 ± 21.4 items individual-1 (dry season). Benthopelagics consumed 63% MPs; cage benthopelagics- Oreochromis niloticus consumed 58.5% MPs. Statistically significant differences in mean MPs were observed in fishes. MPs extracted from grower feed for cage fish was ≥24 items (kg feed)-1. The high metabolic rates of smaller-weighted fishes induced a higher consumption of MPs. From fish health assessment, a positive growth coefficient was observed for Oreochromis niloticus; negative allometric growth was observed for some wild fishes. Spatially, MPs decreased in fish along Basin sites- Asikuma (365 ± 36.58 items individual-1) > Kpong (209 ± 19.71 items individual-1) > Sogakope (71.3 ± 20.86 items individual-1). The Basin sediment was significantly polluted (1950 ± 80 MP items (kg dw)-1), contrary to the freshwater (111.0 ± 11 MP items (L water)-1). 12.3% of MPs polymers characterized had aged and 54% of particles were unknown. MP shapes detected were fibre (97.9%), fragment (2.1%) and film (0.06%). Dominant particle sizes (0.50-2.50 mm, 85%) were black- and blue-coloured. Major polymers were acrylates-polyurethane-varnish (45.7%) and PVC (39%). Lower contributions were obtained from PET, PA, PP, PE, and PE-Cl. An estimated freshwater-fish annual intake (cage: 2561; wild: 4785 MP items (person year)-1) exceeded the recommended EUMOFA/NOAA guidelines (518-3078 particles (year capita)-1). From this study, plastic aquaculture infrastructure from fish cages, effluents, and fishmeal contributed to MPs consumed by fish. This study provides baseline data on MPs distribution within the Volta Basin, Ghana.

Impounded dams can deteriorate water quality and affect its potability; yet, changes may also result from natural processes rather than solely from damming. A decade after the impoundment of the Bui Reservoir in Ghana, this study comprehensively assessed the water quality at seven sampling stations (October 2020-November 2021) by analyzing 26 physicochemical parameters. Profiles of pH, temperature, and dissolved oxygen were measured in situ using a YSI EXO II Sonde. Principal component analyses identified sulfates, total dissolved solids, alkalinity, total hardness, calcium hardness, magnesium hardness, and conductivity as key parameters influencing Bui Reservoir's water quality across pre-wet, post-wet, dry, and wet seasons. Most parameters were within WHO/EU/USEPA freshwater standards, except turbidity, color, and ammoniacal nitrogen. Spatial and temporal trends showed a general decrease in concentrations of many physicochemical parameters since impoundment. Compared with other major Ghanaian reservoirs, Bui recorded the lowest concentrations for most nutrients and ions, indicating improved water quality despite minor inputs from agricultural runoff and market-area waste. This study provides the first decade-scale, multiseasonal assessment of Bui Reservoir's water quality, combining extensive physicochemical data with multivariate analysis. It establishes a robust new baseline and offers actionable evidence for managing large tropical reservoirs under increasing land use and climate pressures.

In this study, microplastic (MP) contamination was investigated in 24 marine fish species from 3 environmental hotspots- Labadi, Teshie, and Jamestown, along Ghana's Gulf of Guinea coastline. Specific fish species studied included Pseudotolithus senegalensis, Sphyraena guachancho, Brachydeuterus auratus, Chloroscombrus chrysurus, and Ethmalosa frimbriata. Fifty-eight percent of the total MPs were detected in the gastrointestinal tracts, and 42% detected in gills of 177 individual fish tested in this study. Labadi showed the highest contamination levels [mean MP concentration: 22 ± 19 (items fish)-1]. Omnivorous fish species had the highest mean ingestion rate of MPs (19.4), surpassing both carnivorous (17.7) and herbivorous species (13.5), and indicating dietary habits as a significant factor in MP bioaccumulation. White-coloured MP films (60%) of sizes: 100-1000 µm were the dominant ingested shape. Other MP shapes included fragments (26.3%), fibres (10.5%), beads (1.05%), and foam (0.61%). Using advanced spectroscopic technique such as Laser Direct Infrared (LDIR) Imaging, 16 MP polymers were characterized with polyvinyl chloride (PVC) being the prevalent MP polymer type (80%). The study observed a strong positive correlation between carnivorous demersal and omnivorous pelagic-neritic fish for specific MP polymers, suggesting that factors other than polymer density influence MP consumption patterns for fish habitats within the water column. The annual MP exposure to Ghanaian adults via fish consumption [(194-29,239 MP items (person year)-1] significantly exceeded the European Safety guidelines [518-3078 (items year)-1], emphasizing dietary habits and environmental pollution as key factors. This study provides a critical baseline on MP pollution in Ghanaian marine ecosystems, highlighting the urgent need for interventions to mitigate plastic pollution, protect marine biodiversity, safeguard marine food, and public health in West Africa.

In Ghana, Nile tilapia is one of the most commonly cultivated fish species. Bacterial infections, which mostly occur in intensive fish farming, are considered to be the most significant health issue facing these culture systems in Ghana's aquaculture industry. To prevent, and treat bacterial infections and promote fish growth, antimicrobials are often used, and in most cases at unregulated doses. However, this misuse and neglect of withdrawal durations for such antimicrobials may result in drug residues showing up in fish edible tissue, posing a risk to human consumers. To evaluate the risk to consumers, this study screened for antibiotic residues in popular tilapia fish sold at a retail outlet in Tema. Using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC/MS/MS), the study analysed the levels of 12 antibiotics present in 24 tilapia samples sold at a retail outlet in Tema. Erythromycin, tetracycline, oxytetracycline, and amoxicillin were detected at varying levels, with frequencies of 20.8 %, 62.5 %, 58.3 %, and 54.2 %, respectively. The highest concentration of 3.521 ± 0.32 μg/kg was found for oxytetracycline, while erythromycin had the lowest concentration (0.276 ± 0.11 μg/kg) in the samples. According to the study, the levels of antibiotics detected in the sampled tilapia were lower than the maximum residue limits (MRL) recommended by the WHO. Additionally, both the hazard quotient (HQ) and hazard index (HI) values were less than one. Therefore, consuming retail farmed tilapia purchased from the commercial outlet in Tema metropolis was deemed to pose no significant risk to human health. However, regular monitoring of antibiotics and other contaminants is necessary to minimise their potential impacts on human health.

Reliable estimates of sediment fluxes into rivers provide valuable information for current and future water resource development and management. In this study, empirical equations relating discharge to suspended sediment loads were developed for the three major tributaries (Black Volta, White Volta, and Oti) of the Volta Lake. The empirical equations were fed with projected future river discharges for the three tributaries, to estimate the suspended sediment fluxes into the Volta Lake for the future (2051-2080) relative to a baseline period (2014-2016). The Soil and Water Assessment Tool (SWAT) was used to model the projected discharges. The SWAT model was driven by downscaled climate projections from two regional climate models (RCA4 and RACMO22 T) forced by two emission scenarios (RCP 4.5 and RCP 8.5) from the IPCC Fifth Assessment. Compared to the baseline, the estimated future sediment fluxes show average increments of about 19% and 28%, respectively under RCP 4.5 and RCP 8.5. This has negative consequences as less water is stored for hydropower generation and the lake water becomes more turbid, which inhibits zooplankton and fishery production. The result underscores the need to improve the management of the Lake's watershed by ensuring proper landcover/use planning, afforestation and enforcing regulations on land degradation and general environmental conservation.

The common use of antimicrobials in food-animal production can lead to drug residues in edible tissues for consumers. However, immunomodulators enhance immune responses and vaccine effectiveness. A new perspective explores bacterial extracellular bioactive molecules (EBMs) in food-animal production to modulate host immune responses, potentially transforming pathogen management and antimicrobial use. This study investigates the immunogenic potential of Aeromonas hydrophila-derived EBMs (Antigens) to enhance the immune system. Four Antigens were administered intraperitoneally to Oreochromis niloticus (Nile Tilapia). Antigens 2 and Antigens 3 boosted fish immune competence within 21 days. Remarkably, Antigens 3 induced robust immunity against A. hydrophila with a single dose, notably enhancing antibody-based immune responses. The increased antibody activity suggests Antigens 3 could be a vaccine candidate, promising further research and potential application in food-animal production to improve disease control. This study highlights immunomodulators' potential in reshaping disease management in the food-animal industry, emphasizing the benefits of focusing on bacterial EBMs to reduce reliance on antimicrobials and achieve sustainable disease prevention.

Over the past decade, the aquaculture sector in Ghana has experienced tremendous growth-driven mainly by large-scale cage aquaculture. Pond aquaculture, traditionally extensive and with limited external inputs, has been transforming over the same period. Farm profitability was wide-ranging, between -12.00 and 46.00 Ghanaian cedi (GHC) per square meter (m(2)), with an average of GHC 8.82/m(2) for farmers active in 2019. Despite wide variability in production and profits, the majority of farmers experienced positive profits-on average, GHC 3.24 per kilogram of tilapia produced, or a 27% profit margin. Farmers who adopted good aquaculture practices and intensified their production have high productivity and positive profits. Nonetheless, the cost to produce 1 kg of tilapia in Ghana (roughly US$1.51 on average) was much higher than in other major tilapia-producing countries (averaging roughly US$0.78 to 1.29). COVID crisis further affected fish farmers: 54% experienced difficulties in accessing inputs, 56% experienced difficulties selling their fish, and farmgate fish prices went down in April-August, although slowly bounced back by end of 2020. Improving the competitiveness and resilience of Ghanaian tilapia sector will require improved seed, increased adoption of good management practices, lower-cost quality feed, and enabling policies and regulations.

Aquaculture in Ghana is experiencing tremendous growth, led mainly by large-scale commercial cage operators. A major objective of the government and its partners is to ensure that this rapid growth is sustainable and includes small-scale farmers and poor rural producers. This paper evaluates the aquaculture trainings implemented in six main tilapia-producing regions in Ghana as part of the Ghana Tilapia Seed Project. The impact evaluation is designed as a cluster randomized controlled trial, with half of the producing districts randomly-assigned as the treatment and the rest as the control, complemented by qualitative interviews. One year after the trainings, results show positive impacts on the adoption of good record-keeping, water management, and some biosecurity practices, and on productivity and incomes. In terms of mechanism, improved management practices resulted from reducing overstocking, reducing inbreeding, maintaining water level for fish ponds, regular pond clearing and establishing physical barriers, following advice and recommendations on feeding practices, and complementing feeding practices with farmers' own feed formulation. Half of the trained farmers experienced lower fish mortality, faster growth, and heavier fish at harvest. Marketing and processing advice through the trainings and complementary FishConnect WhatsApp platform likely contributed to higher incomes, although the platform's coverage and regular updating can be improved.

Acceptance of cage fish farming within Volta Lake in Ghana, was assessed in the lake’s riparian sub-communities by estimating opinion case of community members generally and specifically on issues including Interference of fish culture with fishing; Cage culture interference with local boat transportation activities; Integration level of cage fish culture into other lake activities; Awareness of lake’s community of the lake as a multipurpose resource; Primary occupation of community members; Co-existence level of fish farm operators and communities and cumulative acceptance of fish culture compared to other lake uses and users currently and in the future when the lake is zoned. Methods used were Formal survey and Focus Group Discussions (FGD) in two conceptualized zones (Afram Plains and Asuogyaman) of the lake and data was analyzed by SPSS. A study was undertaken to enhance integration and acceptance of cage fish culture into activities on the Volta Lake and by extension on potential other water bodies where cage fish culture might be practiced. Results indicated that several mutually beneficial situations existed between cage fish farming operators and lake communities. However, there were also conflict flashpoints between cage fish farming practices and livelihood activities of communities at some places as well as fish culture-related outcomes, such as effluents of the culture on lake water quality for communities. The benefits of cage fish farming to communities observed in the results confirm some previous reports. Suggestions of communities to the resolution of conflict flashpoints of operations with operators of cage fish farming provide avenues for enhanced integration thus acceptance and sustainability of cage culture in riparian communities of the lake and other water bodies that could be found suitable for cage fish culture.

Aquaculture in Ghana is experiencing tremendous growth, led mainly by large-scale commercial cage operators. A major objective of the government and its partners is to ensure that this rapid growth is sustainable and includes small-scale farmers and poor rural producers. This paper evaluates the aquaculture trainings implemented in six main tilapia-producing regions in Ghana as part of the Ghana Tilapia Seed Project. The impact evaluation is designed as a cluster randomized controlled trial, with half of the producing districts randomly-assigned as the treatment and the rest as the control, complemented by qualitative interviews. One year after the trainings, results show positive impacts on the adoption of good record-keeping, water management, and some biosecurity practices, and on productivity and incomes. In terms of mechanism, improved management practices resulted from reducing overstocking, reducing inbreeding, maintaining water level for fish ponds, regular pond clearing and establishing physical barriers, following advice and recommendations on feeding practices, and complementing feeding practices with farmers’ own feed formulation. Half of the trained farmers experienced lower fish mortality, faster growth, and heavier fish at harvest. Marketing and processing advice through the trainings and complementary FishConnect WhatsApp platform likely contributed to higher incomes, although the platform's coverage and regular updating can be improved.

Although fish farming provides numerous benefits in the areas of employment, food security, nutrition, trade, and foreign exchange, among others, intensive cage culture operations could cause environmental pollution. The influence of cage culture operations on the quality of the physical and chemical variables in the water column of Lake Volta in Ghana was assessed in this study. The physical and chemical variables were measured from April 2013 to March 2015 following analytical procedures described in the standard methods for the examination of water and wastewaters. A noticeable decrease in oxygen and temperature was observed with increasing depth. No major variances in concentrations of nitrate, nitrite, ammonia, phosphate (dissolved nutrients), chlorophyll-a, dissolved oxygen, secchi depths, and total suspended solids between the cage site and the reference site were detected. There seemed to be no considerable cage impact on the water perhaps due to dilution and the water currents of 0.061 ms-1 which was capable of dispersing wastes from the cages. Consumption of waste feeds by wild fishes which gathered in the vicinity of the cage also contributed to the reduction of the impact. In addition, uptake of inorganic nutrients by phytoplankton and microalgae, biological and physical interactions could account for the low impact.

Large lakes throughout the world offer development opportunities for cage aquaculture. However, due to their vast area, identifying the most suitable locations can be a challenge. This is also complicated as lake systems are often multi-use environments, so a strategic approach to managing the resource is required. This study uses geographic information systems (GIS) to develop a broad-scale approach that identifies potential areas that may be suitable for cage aquaculture development. Volta Lake, one the world's largest man-made lakes, is used as a case study. The overall GIS model combines four sub-models, bathymetry, hydrography, water quality and access, and a constraints layer, to identify the most suitable locations for tilapia production. Three different cage sizes are modelled: small, medium and large. The model outputs suggest that approximately 102 km(2) (1.7%), 406 km(2) (6.9%) and 407 km(2) (6.9%) of Volta Lake can be categorized as highly suitable for development of small, medium and large cages respectively. A further 634 km(2) (10.8%), 1264 km(2) (21.4%) and 1055 km(2) (17.9%) can be categorized as suitable for the same. The results can be used by stakeholders and decision makers to identify specific areas where aquaculture development for cage farming of tilapia could be prioritized.

This study involved the determination of sediment quality and heavy metals in the water column and bottom sediment of a selected cage fish farm in Lake Volta, to assess the potential impact of metals and organic matter pollution on the lake due to cage fish farming. Sediment analysis indicated that the texture of all sampling sites was sandy clay loam with sand dominating with a range of 31.5%–81.2%. The organic matter (TOM) ranged from 4.42%–8.89%, while organic carbon (TOC) was from 2.57%–5.22%. Total nitrogen (TN) fluctuated between 0.22% and 0.45%; total phosphate ranged between 0.22% and 5.30%. The TOC, TOM and TN content in the farm sediment were significantly lower than those of the reference sites (ANOVA, p < .05). Lead, copper, cadmium and selenium were not detected in the water. The results revealed that heavy metal concentrations in the water column and sediments were low and within tolerable levels, indicating no influence of metals from fish feed was observed on the lake water quality. However, the farm seemed to have moderate impact on sediment quality from organic matter. Water and sediment quality monitoring should be embarked upon periodically to ensure sustainable cage culture in the Lake Volta.

Abstract Two commercial caged fish farms, located in the Asuogyaman district of the Eastern Region of Ghana, were assessed for their social and economic impacts on rural communities around their locations. Three groups of people; farm managers, farm workers and farmed fish traders were interviewed by the authors using semi-structured questionnaires to obtain data. Identified benefits to the local communities included increased employment opportunities, improved nutrition and health through enhanced availability of fish and improved infrastructure through, for example, construction of vehicular access roads to communities that would not have occurred but for the existence of the fish farm. Benefits to workers of fish farms and their families were in the form of regular incomes, bonuses, possibility of loans and contribution to social security funds by employers (Farms), which also entitled the workers to an old age pension, invalidity pension, survivors' lump sum payment to families of the workers in case of premature death and health insurance. Benefits to the related traders included larger trade opportunities, incomes accrued from the trading activities that were used to benefit themselves, their families and dependents. Other benefits identified as a result of the farms' operations were the development of local auxiliary businesses, such as ice production. The study concluded that the commercial fish farming sector had, and could have greater, positive impacts on the economy of local communities and the country at large. However, the study has not yet been undertaken within communities where negative impacts of caged fish farms may be encountered. Irrespective of this, results of current study suggest that the emerging fish culture industry in Ghana could enhance the contribution of agriculture to national social and economic development.

Over the past decade, the aquaculture sector in Ghana has experienced tremendous growth—driven mainly by large-scale cage farms—but it has been unclear how the rural poor have shared in this growth. A research project has been initiated to help diagnose, design, and test interventions for better inclusion of the rural poor, women, and youth in the tilapia value chain. This report describes the baseline data on 603 small-scale tilapia farmers in Ghana. The data collected during two-hour face-to-face interviews during May–July 2019 are disaggregated by socioeconomic indicators, gender, and age group. Baseline data show that 9 percent of farm managers and owners were women, and an additional 9 percent of farms engaged women in some decision-making. Moreover, women contributed 16 percent of family labor and 5 percent of hired labor on farms. Youth represented 14 and 24 percent of owners and managers, respectively, but contributed 68 percent of the total family and hired labor on farms. A large majority of managers and owners had at least high school education, with a third of owners and a quarter of managers attaining at least a college degree. In Brong Ahafo and Ashanti regions especially, most farmers engaged mainly in crop farming and non-farm businesses as their main livelihood, with fish farming as a small contributor to overall household income and livelihood. Farmers in all regions had poor record-keeping and management practices and low compliance with sanitation, fish health, and food safety standards. A wide variety of input usage, management practices, and performance was observed among fish farms. As a result, the profitability of fish farms was also wide-ranging, between –12.00 and 46.00 cedi per m2, with an average of 8.82 cedi per m2. Despite wide variability in production and profits, the majority of farmers experienced positive profits. On average, a farmer received a profit of 2.4 cedi per kilogram of tilapia produced or a 27 percent profit margin. These encouraging figures indicate that farmers who adopt good aquaculture practices can achieve respectable profits.

AbstractA mass balance model of trophic interactions among ten key functional producer and consumer groups in Lake Volta was constructed using the Ecopath model to study the energy flows and species interactions in the lake. The present study was based on secondary and primary data on fish catch, diet composition, phytoplankton and zooplankton biomasses, collected in 2015 and 2016. Additional information on growth parameters of major species required for balancing the Ecopath model was obtained from sampling and FishBase. The functional groups were detritus, phytoplankton, zooplankton, benthos, prey fish, Tilapia, Bagrus, Chrysichthys, Alestes and Synodontis species. Four trophic levels were identified in the Lake Volta ecosystem, with the energy flow occurring mainly within the first three trophic levels. The calculated ecotrophic efficiency value of the primary producers (phytoplankton: 0.17; detritus: 0.22) indicated they were least exploited, compared to the secondary producers, zooplankton (0.80) and benthos (0.50). All secondary consumers had ecotrophic efficiency values higher than the primary producers, indicating they are exploited in the ecosystem. The main energy flows in the lake were from phytoplankton and detritus at trophic level I, and Bagrus species, the top predator, at a level of 3.30. The network analysis, illustrating a connectance index of 0.43 and an omnivory index of 0.06, in the lake system indicated the ecosystem is unstable, somewhat immature and still in a developing stage.