Demo Cage Aquaculture Guide

Description

Cage aquaculture which involves growing fish in cages suspended in water, while maintaining free exchange of water between the enclosure and the water body started on Lake Malawi in 2004 and Victoria in 2006 and has spread rapidly to other AGLs. There are over 5000 cages on Victoria, about 10 cages on Tanganyika, 400 cages on Kivu, 50 cages on Malawi/Nyassa/Niassa. Cage aquaculture has in less than 20 years, demonstrated capacity to increase fish production to more than 40 kg m-3 compared to less than 2 kg m-3 from land based aquaculture which started in the AGL region more than 60 years ago. Cages have a higher production per unit volume and lower construction costs compared to land based systems targeting the same production. Fish survival rate is high. On-farm operations such as handling and harvesting are more efficient and there are high returns on investments. Cage aquaculture can, however cause pollution of the water body from uneaten feed, excreta and dead fish, may disrupt biodiversity, result in disease outbreak and interfere with other lake uses such as navigation. It therefore needs proper guidance to safeguard the integrity of the water body. There are, however, no lake-specific BMPs and adequate policies to ensure long-term socio-economic and environmental sustainability cage aquaculture on the AGLs.