Characterization of tilapia farming in net cages at a tropical reservoir in Brazil

Fish farming in reservoirs is a growing aquaculture sector in Brazil. This study aimed to characterize Nile tilapia health and production patterns in net cages at a tropical reservoir in Brazil, to provide baseline information for future studies and policies. The study was carried out in 2015, at the Reservoir of Três Marias, Minas Gerais, and involved all (32) fish farmers in the most important fish production area of the reservoir. Tilapia was the only species commercially farmed and was sold to local slaughterhouses. Aquaculture was the sole income-generating activity for 17% of farmers. Only two farms received regular technical assistance. Most farmers cleaned fish cages and tools, did not share equipment with other farms and appropriately discarded dead or dying fish in ditches. Farmers perceived the primary causes of fish mortality in the reservoir to be water temperature and water level (72%), fingerling quality (31%) and improper feed management (24%). Farmers' main concerns were: difficulty in getting environmental licenses (59%), high cost of animal feed (34%) and low water reservoir level (31%). The fish culture in the studied reservoir is an emerging value-chain of small-scale farmers, with limited production technology. Its sustainable development needs to consider environmental issues and requires better access to health and extension services.