Relative Yield Indices of Challawa Gorge Dam, Kano State, Nigeria

Nazeef Suleiman, Idris Ado Yola, Ibrahim Muhammad Ahmed
2017 Greener Journal of Biological Sciences  
Reservoir morpho-metrics and ionic input of Challawa dam, Kano State (Nigeria) were applied to estimate the potential fish yield using morpho-edaphic index (MEI). Physico-chemical parameters of the reservoir were sampled monthly from three stations (Feginma, Sakarma, and Turawa) for the period of six months (March to August, 2017) using standard methods. Potential fish yield estimates of the three sites were determined using the values of the Physico-chemical characteristics of the reservoir
more » ... h the relationship Y=23.281 MEI 0.447 , where Y is the potential fish yield in Kg/ha, MEI is Morphoedaphic index (given in µS/cm) which was obtained by dividing mean conductivity of the reservoir by mean depth. The potential fish yield estimates of the three sites are 88.05, 98.56 and 111.12 Kg/ha. The relative yield index (RYI) which is the ratio of estimated yield with angler harvest, was determined using the relationship RYI= Yobs/Yest ×0.75, where Yest is estimated potential yield in kg/ha and Yobs is anglers harvest in Kg. The anglers were 53.3, 65.7 and 57.05 Kg respectfully, which implied that the relative yield indices were 44.5%, 49.9% and 38.5%. The results of this study showed that, the reservoir's exploitation level was moderate (RYI≤1). Good ionic content, good dissolved oxygen levels, good pH, low-levels of pollution, accounted for the high estimates of the fish yield. Therefore effective management system, implementation of good fishing regulations and practices should be implemented.
doi:10.15580/gjbs.2017.6.111817167 fatcat:lenbp6cvavgztah6ilzlmiufvu