Assessment of the Aquatic Macrophytes and Algae of the Fosu Lagoon, Cape Coast. Ghana

The Fosu Lagoon serves as a major ecological, economic and cultural (religious) significance to the inhabitants of the community. It provides livelihoods for local fishermen, as well as habitat for rare flora and fauna, is of key importance to the local climate and provided recreational opportunities for the inhabitants of Cape Coast. In recent years, increased human activities have led to deterioration of both fresh and coastal waters in many regions of the world. The Environmental Protection Agency of Ghana have rated the Fosu Lagoon as one such lagoon and is considered the third most polluted lagoon in Ghana after the Korle and Chemu lagoons. Climate change variability has been associated with declining water resources among other factors. Climate change studies in Ghana have shown that major basins in the country are already experiencing water stress and with increasing environmental deterioration, limited water availability and pollution would have tremendous negative impact on aquatic ecosystems including coastal waters such as lagoons. The study revealed that the Fosu Lagoon is covered with mats of mixed vegetation (with Paspalum vaginatum and Typha domingensis dominating) which grow around the banks and over shallow sections of the Lagoon and parts of the landing sites. The weeds contribute to health problems by providing suitable habitats, refuge and food for vectors of water-borne and water related diseases (snails Biomphalaria sp. and Bulinus sp. for intestinal and urinary schistosomiasis and mosquitoes for malaria). Other macrophytes present include: Pistia stratiotes, Nymphaea sp., Eleocharis, Ipomoea aquatica, and the duckweeds. The death and decay of the plant matter is leading to the rapid silting up of the Lagoon and therefore a reduction in the volume of water to be stored as well as the quality thereby decreasing the oxygen content and inadvertently affecting the fauna through oxygen demand reduction. It is therefore being recommended that stringent control of anthropogenic pressures through integrated catchment management will ensure the restoration of the Fosu Lagoon.