TANGEM LUCAS LEKU (+237674930502, tangemlucasleku@gmail.com)
TANGEM LUCAS LEKU, OMGBA MARIE THÉRÈSE VIVIANE, MPOMEZOK CHILLY VANESSA GABY, NYAMA JOSEPH, TAMPONO IDEDOU CHRISTELLE.
MINISTRY OF LIVESTOCK, FISHERIES AND ANIMAL INDUSTRIES
YAOUNDE, CAMEROON.
Abstract
The study evaluated water quality and fish biodiversity in four fish ponds at the Obili Aquaculture Unit, located in the Centre Region of Cameroon, from June to November 2022. Monthly sampling was carried out, with physico-chemical parameters measured following Rodier’s guidelines. A multihabitat approach was used for fish capture, employing nets to sample and count fish, which allowed estimation of total fish populations in each pond. Results indicated poorly oxygenated and slightly acidic water conditions, unfavorable for aquatic species production, along with low levels of organic pollution indicators such as nitrates, orthophosphates, and nitrites. The African catfish, identifiable by barbels, absence of scales, a single long dorsal fin, and dark grey coloration with a white ventral side, was present in all ponds. Pond 4 was stocked at a density of 20 catfish per square meter, corresponding to an estimated 8,000 catfish, while only a few Tilapia were observed there. Oreochromis niloticus, an omnivorous grazer feeding on phytoplankton, periphyton, aquatic plants, small invertebrates, benthic fauna, detritus, and associated bacterial films, outnumbered catfish in the other ponds. Catfish stocking was aimed at controlling tilapia populations. The Global Biological Normalized Index (GBNI) indicated poor water quality across the ponds, whereas Sørensen’s similarity coefficient (exceeding 50%) demonstrated good biological similarity among the ponds. Finally, the study suggests promoting macroinvertebrate cultivation as a viable alternative to fishmeal in aquaculture feed.
Key words: Biodiversity, fish, water quality, fish ponds, Obili.