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Modelling catch per unit effort of the Black Volta near the Bui dam in Ghana
Author(s) -
Alhassan Elliot H.,
OforiDanson Patrick K.,
Nunoo Francis K. E.
Publication year - 2017
Publication title -
african journal of ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.499
H-Index - 54
eISSN - 1365-2028
pISSN - 0141-6707
DOI - 10.1111/aje.12330
Subject(s) - catch per unit effort , environmental science , dry season , chlorophyll a , geography , correlation coefficient , fishery , fish <actinopterygii> , zoology , hydrology (agriculture) , statistics , mathematics , biology , cartography , geology , botany , geotechnical engineering
The chlorophyll a concentration and water level of the Black Volta near the Bui dam were studied in relation to fish production as measured by catch per unit effort ( CPUE ) between February 2011 and December 2012. The primary objective was to develop a simple linear regression model for predicting CPUE levels. The mean estimated CPUE for 2011 and 2012 was lower (6.23 kg canoe −1 day −1 ) in the postwet season than in the dry season (10.86 kg canoe −1 day −1 ) with a mean of 7.95 kg canoe −1 day −1 . Hence, the dry season was the most important season for fish catches in the study area. Predictor variables that significantly explained CPUE levels were chlorophyll a (positive correlation) and water level (negative correlation) ( P = 0.0002). The model was validated with independent data from the same Black Volta in 2011 and 2012. This model, CPUE = (0.062 × chlorophyll a ) − (0.456 × water level) + 3.363, explained 91% CPUE variability. Independent validation indicated that the model had the potential to predict CPUE (as a measure of fish production) in the Black Volta near the Bui dam. Hence, the model is also a valuable tool to predict future trends in the CPUE levels of the Black Volta.