Analysis of marine aquaculture developments in Namibia. Environmental, economic and legislative considerations

Abstract

This multidisciplinary analysis of Namibia marine aquaculture developments has found it to have a good potential. Existing Namibian aquaculture laws are comprehensive in nature controlling aspects such as water, land, public health, sanitation and disease, however they ignore fish welfare. Mean temperature of Namibian marine coastal waters in the150 m water depth strata has averaged at 14.07 oC for the last eleven years (1993-2003). The marine waters in the central area of Namibian coastline are colder than the waters both northward and southward. Temperature decreased with water depth at a gradient of about 0.1oC/m in the 100 m water depth strata. Mean salinity averaged at 34.89‰ with low variation in the 100 m water depth column. Species which are considered for aquaculture are ranked on the scale of one to ten according to their respective potentials based on both environmental and economic issues: Oysters (Crassostrea gigas and Ostrea edulis) are ranked at 9/10, Abalone (Haliotis midae) 8/10, Mussels (Mytilus galloprovincialis) 8/10, Rock lobster (Jasus lalandii) 7/10, Rainbow Trout (Oncorhynchus mykiss) 6/10, Hake (Merluccius capensis) with 5/10 and Cobia (Rachycentron canadum) 3/10. Despite the fact that most of the species considered can live within temperature and salinity ranges of Namibian marine coastal waters at different latitudes and depths, their respective farming successes can be enhanced by research to investigate specie-specific conditions that promote their yields. Economically farming of shellfish has better potential than finfish due its low production costs which is partly a result of adjacent nutrient rich Benguela ecosystem and promising investment returns as a result increasing shellfish product demands and prices.