Three Ghanaian reservoirs (Tono, Bontanga and Golinga) were compared through a food web modelling approach (Ecopath with Ecosim) to assess production characteristics and food web structures. The lakes differ in size and morphology, generating specific conditions for fish growth and production. While the two top fishery target species were Sarotherodon galilaeus (L.) and Oreochromis niloticus (L.) in all reservoirs, the mean trophic level of the catch was lowest in the largest and deepest reservoir (Tono) due to higher trophic level species occupying less accessible deep “refuge” habitats. The smallest lake had the highest fish production under optimal conditions of water supply (17.1 compared with 15.5 and 10.1 t/km²/year for lakes Bontanga and Tono), but it appears to be most vulnerable under conditions of drought. For the planning and construction of adequately sized reservoirs used for fishery and irrigation purposes, the water budget (ratio of inflow and evaporation) needs to be estimated.

中文翻译：

---

加纳三个水库食物网结构和渔业生产力的比较评估

通过食物网建模方法（Ecopath 和 Ecosim）比较了加纳的三个水库（Tono、Bontanga 和 Golinga），以评估生产特征和食物网结构。湖泊的大小和形态各不相同，为鱼类的生长和生产创造了特定的条件。虽然所有水库中的两个顶级渔业目标物种是Sarotherodon galilaeus (L.) 和Oreochromis niloticus (L.)，但在最大和最深的水库 (Tono) 中，由于较高的营养级物种占据，渔获物的平均营养级最低。难以接近的深“避难所”栖息地。在最佳供水条件下，最小的湖泊的鱼类产量最高（17.1，而 15.5 和 10.1 t/km ²/年（Bontanga 和 Tono 湖），但它在干旱条件下似乎最脆弱。为了规划和建设用于渔业和灌溉目的的足够大小的水库，需要估计水预算（流入和蒸发的比率）。