The Efficiency of a stand-alone Recirculating Aquaculture System for tilapia production in cold highland Kenya: a comparison with earthen pond culture
DOI:
https://doi.org/10.65869/sar.v5.i2.157Keywords:
Recirculating Aquaculture System, tilapia, Kenya, aquaculture intensification, cold highlandsAbstract
Kenya's per capita fish consumption of 4.5 kg/year is well below the global average of 20.3 kg, partly due to the unsuitability of cold highland regions for conventional pond aquaculture. This study evaluated the production efficiency of a stand-alone Recirculating Aquaculture System (RAS); the FisHub model, compared to an earthen pond under cold highland conditions in Limuru, Kenya (annual mean temperature: 19°C; altitude: 2,500 m asl). All-male Oreochromis niloticusfingerlings (25 ± 0.5 g) were cultured for 60 days in the FisHub RAS (50 m³, 120 fish/m³) and an earthen pond (300 m3, 3 fish/m2). Productivity in the FisHubwas significantly higher (13.3kg/m³ as compared to 0.8 kg/m³; Mann-Whitney U, p < 0.01), with daily growth rates of 2.2 and 0.84 g/day, and food conversion ratios of 1.0 and 2.1, respectively. Multiple linear regression identified morning dissolved oxygen(p < 0.01), morning temperature (p = 0.042), and pH (p = 0.039) as significant productivity determinants. These results demonstrate that stand-alone RAS can overcome the temperature and oxygen constraints limiting conventional aquaculture in cold highlandenvironments, offering a viable pathway to increase Kenya's domestic fish production.
References
Clough, S., Mamo, J., Hoevenaars, K., Bardocz, T., Petersen, P., Rosendorf, P., et al. (2020). Innovative technologies to promote sustainable recirculating aquaculture in Eastern Africa: A case study of a Nile tilapia hatchery in Kisumu, Kenya. Integrated Environmental Assessment and Management, 16(6), 934–941. https://doi.org/10.1002/ieam.4295
Jacobsen, D., Rostgaard, S., & Vásconez, J. J. (2003). Are macroinvertebrates in high-altitude streams affected by oxygen deficiency? Freshwater Biology, 48(11), 2025–2032. https://doi.org/10.1046/j.1365-2427.2003.01140.x
Obwanga, B., Soma, K., Ayuya, O. I., Rurangwa, E., van Wonderen, D., Beekman, G., et al. (2020). Exploring enabling factors for commercializing the aquaculture sector in Kenya (3R Research Report 011). Centre for Development Innovation. https://doi.org/10.13140/RG.2.2.19796.76164
Opiyo, M. A., Marijani, E., Muendo, P., Odede, R., Leschen, W., & Charo-Karisa, H. (2018). A review of aquaculture production and health management practices of farmed fish in Kenya. International Journal of Veterinary Science and Medicine, 6(2), 141–148. https://doi.org/10.1016/j.ijvsm.2018.07.001
Wurts, W. A. (2003). Daily pH cycle and ammonia toxicity. World Aquaculture, 34(2), 20–21.
Xiao, R., Wei, Y., An, D., Li, D., Ta, X., Wu, Y., et al. (2019). A review on the research status and development trend of equipment in water treatment processes of recirculating aquaculture systems. Reviews in Aquaculture, 11(3), 863–895. https://doi.org/10.1111/raq.12270
Xie, S., Zheng, K., Chen, J., Zhang, Z., Zhu, X., & Yang, Y. (2011). Effect of water temperature on energy budget of Nile tilapia, Oreochromis niloticus. Aquaculture Nutrition, 17(3), e683–e690. https://doi.org/10.1111/j.1365-2095.2010.00827.x
Yuan, J., Xiang, J., Liu, D., Kang, H., He, T., Kim, S., et al. (2019). Rapid growth in greenhouse gas emissions from the adoption of industrial-scale aquaculture. Nature Climate Change, 9(4), 318–322. https://doi.org/10.1038/s41558-019-0425-9
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