Indoor Aquaculture Potential of Duckweed (Lemna minor) and the Need for Adoption in Kenya

Abstract

Duckweed (Lemna minor) culture has been explored as a possible macrophyte based ingredient for partial or full substitution of both soy bean or fish meal in fish feeds in China and India but has seldom been explored in Kenya to establish its growth conditions. To demonstrate the culture potential of L. minor in aquaculture, culture technique was homogenized in indoor plastic tanks using chicken manure at an optimum water depth of 30 cm. Temperature ranged from (25.84±0.19) to (28.24±0.08) °C. After 10 days L. minor attained 100% cover and was harvested three times in a month. The overall yield was (1.09±0.09) kg/m3/month. The Relative Growth Rates was higher during the first harvest (0.38 g/day) and decreased in subsequently (0.12 and 0.10 g/day) for the second and third harvests respectively. Dissolved oxygen decreased with L. minor growth and ranged between (0.84±0.19) and (2.52±0.52) mg/L. pH. values ranged between (5.89±0.32) and (7.23±0.23) throughout the study period. The present study demonstrates that L. minor can be cultured using cheap and locally available organic manure in aquaculture sector. Therefore, there is need to embrace L. minor culture technologies by small scale farmers for sustainable aquaculture production in Kenya.