A major constraint to science-based fish stock management in West Africa is the lack of reliable data on target stocks. This especially holds true for inland fisheries, such as those that operate in reservoirs. Due to the low availability of resources and population data, and the limited number of fisheries experts in the region, state institutions and investigators rely heavily on simple catch statistics and empirical models for their estimations of fish production and potential yields. This paper reviews data from the FAO, and published articles and reports on West African reservoirs, with special reference to their morphometric and environmental features in relation to fish catch. In addition, we analyse primary data on three focus reservoirs. First, to improve and update available models of potential harvests from reservoirs, we regress fish catch data against reservoir surface area data for 30 reservoirs in West Africa, yielding the following equation: Catch (tonnes/year) = 17.3 × Area (km2)0.8626. The equation accounts for 95.7% of the variation observed in the fish catches. Analysis of covariance of small (<2 km2) and large (>2 km2) reservoirs shows no significant difference (F = 0.5895, p = 0.45) in the slopes of the two groups. Second, we apply multiple regressions to a sub dataset of 15 reservoirs with surface area and mean depth as predictors; and we also explore reservoir age as a further variable. We find that fisheries productivity is inversely correlated with both mean depth (r = -0.49) and surface area (r = -0.32), but there is no significant correlation found with reservoir age (r = 0.03).
Abobi S.M. and Wolff M. (2020) West African reservoirs and their fisheries: An assessment of harvest potential. Ecohydrology & Hydrobiology 20(2): 183-195. 10.1016/j.ecohyd.2019.11.004
@article{Abobi2020,
Title = {West African reservoirs and their fisheries: An assessment of harvest potential},
Author = {Abobi, Seth Mensah and Wolff, Matthias},
Editor = {},
Journal = {Ecohydrology & Hydrobiology},
Year = {2020},
Pages = {183-195},
Volume = {20},
Doi = {10.1016/j.ecohyd.2019.11.004},
Abstract = {A major constraint to science-based fish stock management in West Africa is the lack of reliable data on target stocks. This especially holds true for inland fisheries, such as those that operate in reservoirs. Due to the low availability of resources and population data, and the limited number of fisheries experts in the region, state institutions and investigators rely heavily on simple catch statistics and empirical models for their estimations of fish production and potential yields. This paper reviews data from the FAO, and published articles and reports on West African reservoirs, with special reference to their morphometric and environmental features in relation to fish catch. In addition, we analyse primary data on three focus reservoirs. First, to improve and update available models of potential harvests from reservoirs, we regress fish catch data against reservoir surface area data for 30 reservoirs in West Africa, yielding the following equation: Catch (tonnes/year) = 17.3 × Area (km2)0.8626. The equation accounts for 95.7% of the variation observed in the fish catches. Analysis of covariance of small (<2 km2) and large (>2 km2) reservoirs shows no significant difference (F = 0.5895, p = 0.45) in the slopes of the two groups. Second, we apply multiple regressions to a sub dataset of 15 reservoirs with surface area and mean depth as predictors; and we also explore reservoir age as a further variable. We find that fisheries productivity is inversely correlated with both mean depth (r = -0.49) and surface area (r = -0.32), but there is no significant correlation found with reservoir age (r = 0.03).},
}
TY - JOUR
AU - Abobi, Seth Mensah
AU - Wolff, Matthias
TI - West African reservoirs and their fisheries: An assessment of harvest potential
T2 - Ecohydrology & Hydrobiology
PY - 2020
SP - 183-195
VL - 20
DO - 10.1016/j.ecohyd.2019.11.004
AB - A major constraint to science-based fish stock management in West Africa is the lack of reliable data on target stocks. This especially holds true for inland fisheries, such as those that operate in reservoirs. Due to the low availability of resources and population data, and the limited number of fisheries experts in the region, state institutions and investigators rely heavily on simple catch statistics and empirical models for their estimations of fish production and potential yields. This paper reviews data from the FAO, and published articles and reports on West African reservoirs, with special reference to their morphometric and environmental features in relation to fish catch. In addition, we analyse primary data on three focus reservoirs. First, to improve and update available models of potential harvests from reservoirs, we regress fish catch data against reservoir surface area data for 30 reservoirs in West Africa, yielding the following equation: Catch (tonnes/year) = 17.3 × Area (km2)0.8626. The equation accounts for 95.7% of the variation observed in the fish catches. Analysis of covariance of small (<2 km2) and large (>2 km2) reservoirs shows no significant difference (F = 0.5895, p = 0.45) in the slopes of the two groups. Second, we apply multiple regressions to a sub dataset of 15 reservoirs with surface area and mean depth as predictors; and we also explore reservoir age as a further variable. We find that fisheries productivity is inversely correlated with both mean depth (r = -0.49) and surface area (r = -0.32), but there is no significant correlation found with reservoir age (r = 0.03).
ER -
