Benthic macroinvertebrates as indicators of water quality: A case study of estuarine ecosystems along the coast of Ghana.

Increasing human activities in coastal areas of Ghana have led to the degradation of many surface waterbodies, with significant consequences for the ecosystems in the affected areas. Thus, this degradation extremely affects the health of ecosystems and disrupts the essential services they provide. The present study explored the use of benthic macroinvertebrates as an indicator of estuarine degradation along the coast of Ghana. Water and sediment samples were collected bimonthly from Ankobra, Kakum and Volta estuaries for physicochemical parameters, nutrients and benthic macroinvertebrates. The findings revealed the dominance of pollution-tolerant taxa such as Capitella sp., Nereis sp., Heteromastus sp., Tubifex sp., Cossura sp. and Chironomous sp. in Kakum Estuary while pollution-sensitive taxa such as Scoloplos sp., Euridice sp., Lumbriconereis sp. and Pachymelania sp. in the Volta Estuary. The species-environment interactions showed dissolved oxygen, temperature, salinity, orthophosphate, nitrates, ammonium, electrical conductivity, turbidity, and chemical oxygen demand as the most significant parameters that complement the use of benthic macroinvertebrates as indicators of environmental quality in the studied estuaries. There were correlations of some benthic macroinvertebrate taxa with environmental factors in the estuaries suggesting low, moderate and high levels of pollution in the Volta, Kakum and Ankobra estuaries, respectively. Nevertheless, the study finds Kakum Estuary to be the ecologically healthiest estuary than the Volta and Ankobra Estuaries. Therefore, the study has shown benthic macroinvertebrates as a key indicator of ecosystem health alterations, and it is recommended that they should be incorporated with other environmental data for pollution monitoring in Ghanaian coastal waters.

Assessment of environmental degradation in two coastal communities of Ghana using Driver Pressure State Impact Response (DPSIR) framework.

In this study, a qualitative research method using Driver Pressure State Impact Response (DPSIR) framework was employed to assess the drivers of environmental degradation and their implications on Anlo and Sanwoma coastal communities in the Western Region of Ghana. Pollution Index (PI) and Environmental Risk Factor (ERF) were estimated in Pra and Ankobra estuaries, respectively, in Anlo and Sanwoma communities to complement the qualitative assessment in the studied coastal communities. The state and condition of the coastal ecosystems are critical to the well-being and livelihood of the residents of the two coastal communities. Therefore, it was important to assess the drivers of environmental degradation and their consequences on the coastal communities. The findings showed that the coastal communities were severely degraded and were in a vulnerable state due to the impact of drivers such as gold mining, farming, improper waste disposal, and illegal fishing that pressurize the environment. Also, PI and ERFs showed that the estuaries in Anlo and Sanwoma coastal communities were contaminated with metals such as arsenic, lead, zinc, and iron. Some of the impacts of the environmental degradation on the communities included reduction in fish catch and health-related ailments among the residents of the two communities. Unfortunately, regulatory policies by government and efforts of non-governmental organisations and members of the two coastal communities to address the environmental issues have not yielded the desired results. It is recommended that there should be urgent interventions by policymakers to stop further degradations in the coastal communities to enhance the well-being and livelihoods of the residents of Anlo and Sanwoma.