A multi-criteria decision support system for management of coastal lagoons in Ghana – a case study of the Fosu lagoon, Cape coast

Abstract

A Decision Support System (DSS) tool as an analytical advancement of multiple indicators was adapted to give a synoptic yet holistic view of issues confronting coastal lagoons in Ghana for decision making. This study developed and demonstrated multi-criteria effects of a DSS on a heavily pressured urban coastal lagoon, Fosu lagoon in the Central Region of Ghana, from November 2016 to December 2017. The study involved a review of selected in situ records and analysis of water and sediment parameters; spectrophotometric analyses of limiting nutrients, chlorophyll-a, and heavy metals; biotic assessments of the size classes of the dominant Sarotherodon melanotheron, avifaunal biodiversity, and bacterial counts; and remote sensing of land-use patterns using unmanned aerial vehicle (UAV) imagery. A review of relevant regulations and an institutional network analysis in support of Integrated Coastal Zone Management (ICZM) in Ghana were done. Up to 19% of migratory birds were encountered. The resident African darter, Anhinga rufa, constituted the top piscivorous birds. Digital Elevation Model (DEM) analysis of watershed identified major point sources of pollution and 17% of human encroachment within the regulatory 30m buffer width. Infographic outputs showed ecological health state increased from about 33% to 74% and 78% on addressing priority areas of sustainable resource use and water quality restoration, respectively. It is recommended that a designated policy on Coastal Zone Management should focus on ecological health, with lead organizations such as the Environmental Protection Agency (EPA) and Coastal Development Authority (CODA) tasked to coordinate collaborative and intersectoral management.