Black soldier fly larvae are exceptional ingredients, often used to replace fish meal. They can be easily cultured using waste and by-products. This study assesses the effect of black soldier fly larvae (BSFL) meal on the growth of Oreochromis niloticus raised in captivity, as well as the economic impact of replacing fish meal with BSFL meal in its diet. Black soldier fly larvae (BSFL) were produced for 15 days after egg hatching. The substrate of BSFL production was Soy bran that is a byproduct obtained by processing soy cheese. The larvae of Oreochromis niloticus of average initial weight 0.012 ± 0.00 g were randomly distributed in 15 tanks at a rate of 50 larvae per tank. Five different treatments were applied, with TR (imported feed); T0 (diet with 0% incorporation of black soldier fly larvae meal); T40; T50 and T60 are diets with 40%, 50% and 60% incorporation of black soldier fly larvae meal. The feeding frequency was 4 times/day. Each treatment was tested in triplicate for 28 days. The specific growth rate obtained during the experiment varied significantly (P < 0.05) with the treatments from 2.88 ± 0.09 (T40) to 4.50 ± 0.12%/day (TR). The feed conversion rate (FCR), ranged from 2.25 ± 0.05 (T40) to 1.08 ± 0.04 (T60). The protein efficiency ratio (PER) showed a significant difference (P < 0.05) with the treatment. It ranged from 0.81 ± 0.07 (T40) to 2.34 ± 0.06 (TR). The survival rates varied from (T0) (92.66 ± 3.52) to (T50) (100.00 ± 0.00). The economic conversion ratio (ECR) presented a significant difference (P < 0.05). The best ECR was obtained with T60 (1.62 ± 0.09) and T50 (2.42 ± 0.17). Based on the parameters studied, diet with 40%, 50%, and 60% of BSFL meals showed better performance compared to treatment containing fish meal at 54% (T0). The cost production analyses were used to evaluate the economic impact of utilizing BSFL meal instead of fish meal in O. niloticus feeding. It is recommended to use 50% and 60% substitution rates for better economic profitability.

This research investigated the temporal dynamics of the anthropogenic impact of fishing pressure on the resilience of the fish species Sarotherodon melanotheron (Rüppel, 1858) in the African Lake Toho, located in southwest Benin. The sampling and analysis of monthly length frequency data were conducted from April 2002 to March 2003 and from April 2022 to March 2023 using the FAO-ICLARM Stock Assessment Tool (FiSAT II software program (version 1.2.2.). The analysis of the S. melanotheron population in Lake Toho revealed a significantly diminishing resilience potential, reflected mainly in general reductions in both the average size and weight of individuals. There was a notable reduction in the size of Sarotherodon melanotheron individuals caught between 2002–2003 and 2022–2023, reflecting the increased pressure on juvenile size classes. Catches are now concentrated mainly on immature fish, revealing increasing exploitation before sexual maturity is reached. An analysis of maturity stages showed a decrease in the percentage of mature individuals in the catches (69.27% in 2002–2003 compared to 55.07% in 2022–2023) and a reduction in the number of mega-spawners (4.53% in 2002–2003 compared to 1.56% in 2022–2023). Growth parameters revealed a decrease in asymptotic length (from 32.2 cm to 23.8 cm) and longevity (from 9.37 years to 7.89 years), while the growth coefficient slightly increased. The mean size at first capture and optimal size significantly declined, indicating increased juvenile exploitation. The total and natural mortalities increased, whereas the fishing mortality remained stable. The exploitation rate remained high, despite a slight decrease from 0.69 to 0.65. Finally, the declines in the yield per recruit, maximum sustainable yield, and biomass confirm the increasing fishing pressure, leading to growth overfishing, recruitment overfishing, reproductive overfishing, and, last but not least, a decreasing resilience potential. These findings highlight the growing overexploitation of S. melanotheron in Lake Toho, compromising stock renewal, fish population resilience, sustainability, and production while jeopardizing local food safety.

Small pelagic fish species contribute substantially to the food security and livelihoods of local communities in developing countries. In West Africa, and particularly in Benin, small pelagic fisheries attract many migrant fishers who are key actors in the sector. This study assessed the characteristics and sociocultural impacts of the small pelagic fishery in Benin using qualitative approaches, including focus group discussions (n = 9), in-depth interviews (n = 35), a literature review, direct observations and secondary data. The findings showed that indigenous fishers from Benin and foreign fishers from Ghana are the two major groups of migrant fishers involved in small pelagic fishing in Benin. These fishers mostly use three categories of fishing gear: gillnets, seine nets, and hooks and lines. Over the period 2014–2018 the annual catch fluctuated between 1 123 and 2 040 tonnes, with the peak catch recorded in 2018, with a commercial value of €3 030 587. Apart from migrant fishers, fishmongers constitute another important pillar of the value chain. Conflicts among migrant fishers in the sector in Benin are related to landing fees and fishing gears. We discuss the urgent need to give attention to the sector through quantitative research and law enforcement to ensure its sustainability.

This study investigates the potential of water hyacinth (Eichhornia crassipes) leaves as a protein-rich dietary alternative for Oreochromis niloticus (Nile tilapia). Water hyacinth is an invasive aquatic plant with promising nutritional properties, including moderate protein content and low levels of antinutritional factors. The digestibility of WH leaves was assessed, and their optimal incorporation level in fish feed was evaluated. Apparent digestibility coefficients (ADCs) for WH leaf were 77.49% (dry matter), 69.58% (crude protein), and 59.14% (energy). Six experimental diets containing 0–12% WH leaf were formulated and fed to O. niloticus fingerlings over 45 days. Growth performance, feed utilisation, and carcass composition were analysed. Results showed that inclusion levels up to 6% did not significantly affect growth, feed conversion ratio, or protein efficiency; however, inclusion levels above 6% led to reduced zootechnical performance and a lower nutritional quality of fish flesh. Survival rates remained unaffected across all treatments. The study concludes that WH leaves can be safely included in tilapia diets at a maximum of 6% without adverse effects on growth, feed efficiency, or flesh quality, offering a sustainable feed alternative in aquaculture.

This study analyzes the impact of fishing pressure on the dynamics and resilience of Coptodon guineensis in Lake Toho (southwestern Benin), using size-frequency data (2002-2003 and 2022-2024) processed with FiSAT II. Results show a decline in maximum length and weight (31.3 cm/908 g to 18 cm/119 g), earlier sexual maturity, and a reduction in mature individuals and large breeders. Growth and exploitation parameters indicate reduced longevity, lower yield per recruit, and persistent overexploitation. Overall, the biological and ecological status of the species has deteriorated, undermining its long-term resilience and threatening the food security of local communities dependent on this fishery resource.