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.

Mass production of quality seed is vital for commercial culture and requires prior knowledge of appropriate larval diets and their utilization. Four experiments were sequentially conducted at different periods to evaluate the effect of live and a processed microdiet on growth and survival of Barbus altianalis larvae and juveniles. Larvae were fed exclusively on live prey (Moina and Artemia nauplii), microdiet (57 % Crude Protein), decapsulated Artemia cysts and in combination (Moina + microdiet). The effect on growth was further evaluated in subsequent juvenile trial by co-feeding. Green water effect on larval growth was also evaluated. In the final experiment, 15 day old larvae were raised in fertilized outdoor concrete tanks. Results indicated that each diet affected larval growth significantly different (P < 0.05) with the combination diet (152.05 ± 2.51mg) and decapsulated Artemia (141.14 ± 2.43 mg) performing better than microdiet, Moina and Artemia nauplii in that order. In subsequent juvenile experiment, larvae originally fed decapsulated Artemia (510.13 ± 11.93 mg) and those fed a mixed diet (500.20 ± 11.8 mg) performed better than other diets. Ontogenetic pattern of amylase, lipase and protease activity identified larvae maturation age at 14–21 Days after hatching (DAH) (14.93 ± 0.36–31.5 ± 0.61 mg) with the combination diet. When larvae at 15 DAH were nursed in outdoor tanks, final survival and growth performance increased to 95.3 % and 1112 ± 42.70 mg compared to the indoor nursing at 90.9 % and 355.33 ± 6.44 mg respectively by 75 DAH. Therefore we recommend that any microdiet manipulations and or outdoor nursing be done during or after this period. Microalgae had no direct effect on larval growth (P > 0.05). In this study, larvae were confirmed to utilize the microdiet from exogenous stage but co-feeding produced best average weight (152.05 ± 2.51mg), specific growth rates (4.06 ± 0.19) and survival (90.9 %). This study provided guiding strategies for improved rearing of B. altianalis fingerlings in captivity.

In recent years, intensification of aquaculture production in the Lake Victoria Crescent, Uganda has resulted in increased parasitic disease occurrences. However, despite the efforts made, the parasite burden has continued to cause fish mortality. Notably, the different production systems provide different habitats and environmental conditions for the parasites and understanding of the parasite infestation dynamics in these culture systems may provide better sanitary and farm management strategies for the parasite burden. Therefore, the study compared the parasite prevalence and mean intensity of pond and cage cultured Nile tilapia and also identified statistical associations between parasitic infestation and farm management practices. Across the Crescent, a high infestation rate of 65% (418/640) with Trichodina spp. being most prevalent and abundant, and a 16 parasite taxa; 6 protozoa, 2 monogenea, 2 digenea, 1 crustacea, 3 cestode, and 1 acanthocephala was obtained. Furthermore, nearly all parasites were recovered in 3 fish organs; gills harboring 50% (8/16), intestines with 31% (5/16) and skin with 25% (4/16) of the parasite genera. Fish from Pond grow-out and Hatchery farming system harboured ≥ 11 parasite genera while ≤ 5 parasite genera were found in Cage grow-out (lake) and Cage grow-out (reservoir) farms namely; Pond grow-out: 5 protozoa, 1 monogenea, 2 digenea, 1 crustacea, 2 cestode; Cage grow-out (lake): 2 protozoa, 1 monogenea, 2 digenea; Cage grow-out (reservoir): 2 protozoa, 1 monogenea, and Hatchery: 3 protozoa, 2 monogenea, 2 digenea, 1 crustacea, 2 cestode, and 1 acanthocephala. Definitely, Trichodina spp. and Dactylogyrus spp. were recorded in all culture systems but with Trichodina spp. having the highest prevalence and mean intensity in Cage grow-out (reservoir). After classification of infestation, the comparative assessment between Pond grow-out and Cage grow-out (lake) farming systems revealed that 66 % (12/18) of Pond grow-out farms had normal/ frequent infestation and with one farm having very severe/ severe infestation whereas, 33 % (3/9) of Cage grow-out (lake) had gradual/ rare infestation yet with no farm having very severe/ severe infestation. The Fisher's exact test revealed that in Pond grow-out, the relatively high infestation was significantly associated with all the farm management practices: fish seed source, stocking density, feeding and nutrition, disinfection, control of intermediate hosts, and control of wild fish entry, while in Cage grow-out (lake), the relatively low infestation was only significantly associated with stocking density, feeding and nutrition, and control of wild fish entry. Therefore, the findings from the study suggest that proper farm management practices will reduce on the parasite proliferation in the Crescent.

A study was conducted to determine the estimated parasitic infestation and associated risk factors (Water quality, Farm management practices and External factors such as Intermediate hosts and Wild fish entry) of farmed Nile tilapia in Pond grow-out, Cage grow-out (lake), Cage grow-out (reservoir) farms and Hatcheries in the Lake Victoria Crescent, Uganda. Sixteen parasite genera and 65% (418/640) infestation rate were obtained. However, Pond grow-out farms and Hatcheries did not only constitute 81% and 63% of the parasite genera, but also had the highest mean number of parasite genera per farm of 1 to 7 and 4 to 8 respectively. Cage grow-out (reservoir) farms and Hatcheries had the highest mean prevalence of >0.7. Water quality parameters, farm management practices and external factors varied across the 4 farming systems, with Cage grow-out farms (lake) with the best water quality parameters, farm management practices and control over intermediate hosts and wild fish entry. Using Spatial Areal Unit Modelling with Conditional Autoregressive Priors, out of 16 risk factors, only Intermediate hosts had a significant effect on estimated parasitic infestation. Estimated parasitic infestation of 0.28 (low) or 0.55 (high) prevalence was obtained. All Cage grow-out (reservoir) farms and Hatcheries, and 78% (14/18) of Pond grow-out farms had high estimated parasitic infestation despite their locations, while 75% (3/4) of Pond grow-out farms that had low estimated parasitic infestation were located in Masaka (an area with many minor and less polluted rivers). Fifty-six percent (5/9) of Cage grow-out (lake) had low estimated parasitic infestation and were located in the Southern part of Wakiso, Southern part of Mukono and Southern part of Jinja but far from the Napoleon Gulf. The Cage grow-out farms with high estimated parasitic infestation were found in the Southeastern part of Buikwe (an area with sugar cane plantations and factories) and Southern part of Jinja in the polluted Napoleon Gulf. Therefore, the type of farming system and its location (spatial component) need to be given at-most importance when coming up with management and sanitary control strategies to encounter parasite infestation.

Aquaculture is a key to global food and nutrition security, but intensification has increased disease pressure, antibiotic use, antimicrobial resistance (AMR), and wider One Health concerns. Functional microbial products (FMPs), including probiotics, prebiotics, synbiotics, postbiotics, and paraprobiotics, are widely promoted as sustainable alternatives to antibiotics. However, their growing use has not resulted in sustained replacement of antibiotics in commercial aquaculture practice. This review examined why this gap persists and what conditions are required for these products to contribute credibly to antibiotic reduction. A PRISMA‐guided systematic review was conducted across major scientific databases, yielding 654 records, of which 97 studies were retained for qualitative synthesis. The evidence shows that FMPs can improve growth, feed efficiency, immune response, disease resistance, survival, and, in some systems, water quality. Beyond these performance outcomes, the review identifies host immune modulation as a central biological pathway linking FMPs to disease resilience, particularly through mucosal barrier reinforcement, innate immune priming, activation of humoral and cellular defenses, cytokine and inflammatory regulation, antioxidant protection, and stabilization of the host–microbiome axis. Probiotics had the strongest overall evidence base, synbiotics showed the most consistent combined gains across growth, immunity, and survival, while postbiotics emerged as promising options because of their stability and biosafety advantages. However, direct evidence of sustained farm‐level reductions in antibiotic use remains limited. Multiple interlinked constraints explain this gap including biophysical stress in production systems, inconsistent product quality, misaligned application practices, mechanistic uncertainty, biosafety risk, and weak diagnostic, advisory, and regulatory systems. Overall, FMPs are best understood as preventive and resilience‐building tools rather than direct therapeutic substitutes for antibiotics. Meaningful antibiotic reduction will depend less on product substitution alone and more on integrating these products into stronger health‐management systems supported by quality control (QC), clear deployment protocols, diagnostics, advisory services, and enabling regulation.

Despite ongoing biosecurity and control efforts, aquaculture intensification in the Lake Victoria Crescent has led to a persistent increase in parasitic disease occurrence in cultured Nile tilapia. Notably, different culture systems provide different habitats and environmental conditions for parasites and understanding these dynamics may provide better management strategies. We compared parasitic infection/infestation rates of cultured Nile tilapia in pond-based and cage-based farming systems and identified associations between parasite dynamics and management in the Crescent. Trichodina spp. (most prevalent and abundant) and Cichlidogyrus spp. were found in all systems. Pond systems contained ≥11 parasitic genera while ≤5 were found in cage systems. Parasite dynamics were modelled using generalised linear models with zero-inflated Poisson or zero-inflated negative binomial distributions. Surprisingly, in pond systems, adequate stocking densities and feeding were associated with an increase in Cichlidogyrus spp. abundance, while sourcing seed from fellow fish farmers was associated with a decrease in Trichodina spp abundance. For cage systems, adequate stocking densities and feeding were associated with an increase in Trichodina spp. abundance. Wild fish entry was associated with an increase in Cichlidogyrus spp. abundance while optimal stocking density was associated with a decrease in Cichlidogyrus spp. abundance. These findings highlight the interactions between seasonality and farm management in the control of parasites.