Environmental and socio-economic impact of aquatic weeds on the water of Awba dam: its effect on ecotourism
Fresh water is mankind’s most precious resources, the increasing scarcity of clean fresh water through population growth and development, droughts, contamination, and other factors, places greater demands on the very foundation of the society. Unfortunately, invasive plants and algae are progressively disrupting the ecological balance required for maintaining adequate fresh water resources for flora, fauna, and humans. These macrophytes generally have negative impacts on tourism and recreation. This study was aimed at assessing the environmental and socio-economic impact of aquatic weeds on Awba dam and it overall effect on ecotourism.
The physico-chemical assessment of water samples of the dam was done at dry and wet season in replicates. Water samples were collected from weed infested areas and also from the control site devoid of weed, using Standard laboratory methods. Field survey was done to determine the aquatic weed species present on the dam while an interview with a staff of the maintenance unit was used to estimate the economic impact of the weed on the dam.
Result revealed that parameters such as phosphate (0.11;g/ml - 0.12;g/ml), chloride (21mg/l - 37.33mg/l), sulphate (0.13mg/l to 0.19mg/l) were higher than the required limit while nitrate (1.2 - 2.89mg/l) was below the recommended limit. Turbidity (20.6 FTU - 108.8 FTU), Total dissolved solids (114mg/l - 197.67mg/l) and Total suspended solids (207mg/l - 1559.35mg/l) were higher than the recommended limit. The pH value (2.57) for Station A was also below the recommended limit . A total of 22 species of weed were identified on Awba dam, with Eichornia crassipes and Sacerolepis africana which are of serious environmental importance, been the most dominant weed. The interview with the maintenance unit revealed that millions of naira is been expended in managing and controlling the aquatic weeds.
This study shows that aquatic weeds can permanently alter physico-chemical parameters of freshwater ecosystem if allowed to thrive over long periods. Furthermore, the study has revealed the economical challenge of these weeds to the University administration. This calls for proper management strategies in controlling the spread of these weeds if ecotourism potentials are to be fully harnessed.
Keywords: Aquatic weeds, physico-chemical parameters, water resources, recreation