Fisheries Assessment and Trophic Modelling of Tono, Bontanga and Golinga Reservoirs in Northern Ghana
Tono, Bontanga and Golinga reservoirs are among the top five largest reservoirs in the Northern Ghana. These reservoirs are used for irrigational farming and fishing. They are essential food security and livelihood resource for the rural majority poor in their catchment areas.
Reservoir construction has gained strong attention in Ghana as Government and political parties have repeatedly expressed plans to revamp existing reservoirs and construct new ones. The potential contribution of the reservoirs to inland fish production is huge, granting that the reservoirs are technically and purposefully designed and constructed to provide significant fish production and granting that the fisheries which subsequently develop are sustainably managed. However, the actual benefit derived from most of the existing reservoirs in terms of fish production is insignificant and the reasons are multifaceted, encompassing issues such as unproductive reservoir designs, bad fishing practices, planning and policy, research and development, management and exploitation, finance and human resource, among others.
The Tono, Bontanga and Golinga reservoirs have different physical features and the main objective of this PhD project is to understand how differences in reservoir morphometry (total size, surface area/volume ratio), water budget (inflow, precipitation/evaporation ratio) and physicochemical conditions influence the development of ecosystem structures and fisheries productivity.
The PhD project has three main areas of focus namely:
- Elucidating difference in fisheries productivity of Tono, Bontanga and Golinga reservoirs: Relating age, morphometric and hydrochemical features of the reservoirs to their productivity
- Fisheries assessment of target species of Tono, Bontanga and Golinga reservoirs: Elaborating management advice for Auchenoglanis occidentalis, Oreochromis niloticus, Sarotherodon galilaeus, and Tilapia zillii
- Comparative analysis of biodiversity, food web structure and fisheries productivity of Tono, Bontanga and Golinga reservoirs: Assessing differences in ecosystem attributes among the reservoirs
My PhD project focuses on defining a range of physical attributes and developmental conditions under which man-made reservoirs can provide and sustain significant fisheries production. Moreover, fisheries management in reservoirs requires alternative sustainable management scenarios which are derivable from ecosystem modelling, for example, using ecosystem modelling software ECOPATH with ECOSIM. As observed for other fisheries ecosystems, sustainable exploitation of the Tono, Bontanga and Golinga reservoirs is necessary if the fisheries are to make any significant continuous impacts on the socio-economic life of the rural communities around the reservoirs. Subsequently, the study will elaborate management advice for sustainable exploitation of the reservoirs fishery.
|Prof. Dr. Matthias Wolff||University of Bremen and Leibniz Center for Tropical Marine Ecology (ZMT)|
|Dr. Werner Ekau||Leibniz Center for Tropical Marine Ecology (ZMT)|
|Prof. Dr. Achim Schlüter||Jacobs University and Leibniz Center for Tropical Marine Ecology (ZMT)|