Abstract
World capture fisheries are declining while demand for fish is increasing due to population increase and an upward trend in diet preference where fish is preferred over white meat. It is hoped that aquaculture will help meet this deficit. In Kenya, coastal aquaculture remains under-developed even though over 3900 hectares of land have been designated as suitable for aquaculture. This case study is based on a study where Indian shrimp (Penaeus indicus) were cultured for 106 days, in hapas, inside fertilized ponds at Majaoni in Mtwapa creek, Mombasa district, Kenya. The manures used for pond fertilization were chicken, urea and cow dung. No manure was added in the control treatment. Physical, chemical and biological water parameters were taken weekly, fortnightly and monthly, respectively. Growth performance of the shrimp in terms of weight (g) and length (mm) was monitored fortnightly. The mean growth rates ranged between 1.13 and 2.34% day-1 in the control and chicken manure treated ponds, respectively. The highest net yield (NFY Kg ha-1) and annual production (AP Kg ha-1 yr-1) achieved was 18.87 Kg ha-1 and 64 Kg ha-1 yr-1, respectively, in the cow dung-treated ponds. The data collected from this study formed part of the author's MSc thesis in Aquaculture at the University of Nairobi. A major part of the study was funded by Alcoa Foundation's Conservation and Sustainability Fellowship Program which supported the author as a Practitioner Fellow in 2008. Additional support was provided through the Western Indian Ocean Marine Science Association (WIOMSA) small grant programme.
Nitrite oxidizing bacteria for water treatment in coastal aquaculture system