Algal Diversity and Distribution in The Esp Fish Ponds in Tharaka-Nithi County, Kenya

Abstract

The algal species composition, distribution, abundance and the water chemistry of the ESP fish ponds in Tharaka-Nithi County have remained unknown, although these greatly influence fish production in ponds. The Results presented here are from investigations over a period of six months of a that is an ongoing study Preliminary findings indicate that the major algal taxa in the ESP fish ponds in Tharaka are Chlorophycea and Bacillariophyceae, both with a ubiquitous distribution in the study area. Cyanobacterial species exhibited a higher abundance (with an average of 235 cells ml-1) in the lower zone (Tharaka) than the middle (Itugururu) or upper (Chuka and Chogoria) zones. Among the cyanotoxin-producing species were Aphanocapsa, Anabaena, and Microcystis spp. Algal abundance exhibited a seasonal pattern with higher values during the rainy than the dry seasons. The highest pond water temperature recorded was in the lower zone, reaching a maximum of 31.9 0C in Tunyai (Tharaka). The minimum level of dissolved oxygen was 3.2 mg l-1. Molecular characterization of the algae cyanotoxin level determination and algal biomass are important aspects of and form the next phase of the present study. The results obtained are expected to play a vital role in formulating informed management policies in order to boost fish production in the ESP ponds of the Tharaka-Nithi County and at the national level.