Dwindling Wetland Ecosystems: A Survey of Impacts of Anthropogenic Activity on Marura Wetland, Kenya

摘要

Many developed and developing member States to the Ramsar Convention on conservation of Wetlands have developed their national policies on wetlands conservation and management. Management systems that, on the global extent involve community based approaches have been developed. Nevertheless, many challenges in wetland conservation and management continue to determine the existence and survival of these ecosystems. Several unlike and intensely bad threats including undesirable anthropogenic activities, within the wetland catchment areas and in the wetlands, are a threat to these delicate ecosystems. The main objective of this study was to monitor the water quality using limnological variables from different sampling points of a swamp during the flood and drought period of the wetland. Nutrients such as nitrogen and phosphates were determined. Dissolved oxygen (DO), pH, turbidity, temperature, total solids and conductivity were determined using standard analytical procedures. There were six sampling points, Sampling point 1 was on Sergoit River before water enters Marura Wetland and acted as the control and the other five sampling points were within Marura Wetland, and were sampled in two seasons, wet and dry. The three replicas were collected four times in the dry season (December 2015 to March 2016) and four times during the wet season (April to July 2016). The findings revealed that there is a statistically significant difference between the control and test sample means of nitrates, phosphates, Dissolved oxygen, pH, Turbidity, Conductivity, and Total Solids. The results reveal that there is significance value of p = 0.000, which is below 0.05., and therefore, there is a statistically significant difference among the different parameters in test samples and control. There is a statistically significant difference in turbidity between test samples and control samples as determined by one-way ANOVA (F (11, 36) = 82.340, p = 0.000). There was a statistically significant difference in phosphates between study areas and control samples as determined by one-way ANOVA (F (11, 36) = 39.020, p = 0.000). There was a statistically significant difference in conductivity among the study areas and control samples as determined by one-way ANOVA (F (11, 36) = 651.859, p = 0.000). This study concludes that Marura Wetland is a polluted ecosystem as indicated by phosphorous, turbidity and conductivity that were above specifications by the Kenya National Water Quality Standards (KNWQS). The findings of this study provide an important baseline or insight from which to monitor future change in water quality of Marura Wetland. This study recommends that further studies should be conducted to establish the actual potential of the site and actual points of source pollution and the types of electrolytes dissolved in the waters of Marura Wetland. The study also recommends intervention by local and national authorities to safeguard this dwindling ecosystem.