ABSTRACT
The Muni-Pomadze wetland in the Central Region of Ghana is one of five
internationally-recognised coastal wetlands (Ramsar sites) in Ghana under the
Convention on Wetlands of International Importance. The wetland is known for its rich
variety of biodiversity and unpolluted ecosystem and is fed by a main river called Pratu
along with its tributaries (Ntakofa and Muni Rivers) that flows into the Muni lagoon.
However, the need to produce enough food to feed the ever increasing population has led
to the extensive use of land especially along the banks of the rivers that feed the wetland
for farming activities. This disturbing issue coupled with other anthropogenic activities
has led to an increasing level of pollution in the wetland resulting in water quality
degradation in the river catchment. This has consequently diminished both the local and
international significance of the wetland. In this light, this research sought to assess the
impact of farming and other anthropogenic activities along the Pratu River and its
tributaries and consequently the Muni lagoon in the wetland by determining the source,
types and level of pollution existing in the river basin. Water samples from the Pratu
River, Ntakofa River and the Muni lagoon were analysed for physico – chemical
parameters (pH, Temperature, Electric Conductivity, Salinity, Total Dissolved Solids,
Alkalinity, Dissolved Oxygen, Biological Oxygen Demand, Chemical Oxygen Demand
and Total Hardness) using titrimetry, Hach Sension 5 Conductometer and Hach pH
Meter; trace metals (Iron, Copper, Zinc, Lead, Cadmium, Cromium and Mercury) using
the Atomic Absorption Spectrometer; ions (Na, Ca, K, Mg, Cl-
, )
using the Flame Photometry, UV-Visible Spectrophotometry and titrimetry. Pesticide
residues (Organochlorines, Organophosphates and Synthetic Pyrethroids) were also
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analysed using the Gas Chromatography–Electron Capture and Pulse Flame Photometric
Detections. Results of the physical analysis showed high concentration of EC ( 20655.77
µS/cm, 16822.32 µS/cm and 55600 µS/cm respectively), TDS, (13761.77 mg/L,
10775.89 mg/L and 33333.33 mg/L respectively) and salinity (14.95, 11.79 and 37.33
respectively) depicting a high level of dissolved ions in the basin. High levels of total
hardness were 3833.85 mg/L, 2942.222 mg/L and 6933.333 mg/L respectively and COD
were 10.35 mg/L, 14.31mg/L and 13.8mg/L respectively. This may be attributed to the
high levels of dissolved ions and anthropogenic activities involving farming practices,
illegal gold mining operations, domestic effluents and other chemical effluents that enter
the river through surface run-off. Major cationic dominance pattern for the basin was
Na>Ca>K>Mg and that of the anions were Cl > . The observed
pattern shows that Na and Cl concentrations are dominant in the basin. This condition
may be attributed to the effect of aerosols from the sea and Na and Cl ions which may be
present in the soils close to the river banks (evidenced by salt-like precipitates on the soil
surface). Results of trace metals and pesticide analysis in the sediment of the river basin
showed that, most of the metals and the pesticides found were all adhered to the soil
sediment in low concentrations hence may not pose a threat to the river‘s quality. Sodium
Adsorption Ratio (SAR) was measured in the basin. 21.02, 29.44 and 51.02 respectively
for the three parts of the basin showed that the river is not suitable for irrigation (results
were >13). However continual use of the river as a source of irrigation may cause stunted
growth of the crops resulting in low yield. This may necessitate increased fertilizer use
and consequently impact the river by eutrophication. Based on these findings, it is
recommended that further water quality analysis be conducted on the river on an annual
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basis in order to ascertain the pollution progress of the river and its impact on the
wetland. Secondly, SAR measurements should be conducted on the soils of the farmlands
to give more detailed information on the degree of sodicity of the soil. This will help the
farmers make an informed decision on best farming practices.
Eastern Network, L (2021). Impact Of Farming Activities On The Water Quality Of The Pratu River And Its Tributaries In The Muni-Pomadzi Wetland. Afribary.com: Retrieved April 15, 2021, from https://afribary.com/works/impact-of-farming-activities-on-the-water-quality-of-the-pratu-river-and-its-tributaries-in-the-muni-pomadzi-wetland
Library, Eastern Network. "Impact Of Farming Activities On The Water Quality Of The Pratu River And Its Tributaries In The Muni-Pomadzi Wetland" Afribary.com. Afribary.com, 03 Apr. 2021, https://afribary.com/works/impact-of-farming-activities-on-the-water-quality-of-the-pratu-river-and-its-tributaries-in-the-muni-pomadzi-wetland . Accessed 15 Apr. 2021.
Library, Eastern Network. "Impact Of Farming Activities On The Water Quality Of The Pratu River And Its Tributaries In The Muni-Pomadzi Wetland". Afribary.com, Afribary.com, 03 Apr. 2021. Web. 15 Apr. 2021. < https://afribary.com/works/impact-of-farming-activities-on-the-water-quality-of-the-pratu-river-and-its-tributaries-in-the-muni-pomadzi-wetland >.
Library, Eastern Network. "Impact Of Farming Activities On The Water Quality Of The Pratu River And Its Tributaries In The Muni-Pomadzi Wetland" Afribary.com (2021). Accessed April 15, 2021. https://afribary.com/works/impact-of-farming-activities-on-the-water-quality-of-the-pratu-river-and-its-tributaries-in-the-muni-pomadzi-wetland