River Depth Alterations Resulting from Intensive Mechanical Dredging of Ekole Creek, Nun River Bayelsa State

Abstract

River banks are crucial to humans, because of the accessibility to water for various purposes. The banks of Ekole Creek are occupied with communities that depend on it for habitation and economic benefits. This study investigated the effects river depth alterations resulting from intensive mechanical dredging. An interview was conducted for 80 respondents using structured questionnaire. The points for sampling were; ‘Dredge point I and Dredge point II’ of the dredging sites, then ‘Upstream and Downstream’ taken randomly as control. Hydrographic survey was conducted using an echo sounder installed on a speed boat and driven across the 270m wide creek and observations recorded. Results of the questionnaire indicated that about 72.5 % agreed strongly that Heavy duty mechanical dredgers were used, 87.5 % of the respondents agreed that operations of dredging had lasted for more than five years, the respondents also confirmed that dredging had changed the river depth, while 85 % of participants strongly agreed that fishing activities were difficult in the region. Echo sounding results indicated that the upstream and downstream points had the maximum depth of 8.81m and 12.79m respectively, while Dredge sites I and II had depths of 21.5m and 17.73m respectively. Dredging activities had caused the increased depth variations, hence the scarcity of fish and exposure of the riverbanks to erosion which threat to life and property of residents communities. It is recommended that routine environmental monitoring to promptly detect the alteration of river depth during dredging activities, be carried out.

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