Sedimentation Rates and Their Ecological Impacts in Badagry Creek, Lagos

Sedimentation is a natural process with profound ecological consequences when accelerated by land use change, dredging operations, and upstream erosion, particularly in lagoonal and estuarine systems. This study measures sedimentation rates and evaluates their ecological impacts in Badagry Creek, Lagos State, South West Nigeria, an estuarine system under pressure from urban expansion, agricultural encroachment, and the proposed expansion of the Badagry Deep Seaport. Sediment trap arrays are deployed at six stations across the creek system for quarterly periods during 2023 to 2024, and retrieved materials are oven-dried and weighed to compute mass accumulation rates expressed in grams per square metre per day. Sediment core analysis provides vertical records of grain size, organic carbon, heavy metal profiles, and diatom assemblages to reconstruct historical sedimentation dynamics. Concurrent benthic macroinvertebrate surveys assess community responses to varying sediment loads using the AMBI biotic index. Loss-on-ignition measurements quantify organic matter content as an indicator of eutrophication-linked sedimentation. Findings are expected to reveal elevated sedimentation near creek headwaters and around boat traffic corridors. Reductions in benthic invertebrate richness and the dominance of pollution-tolerant taxa near high-sedimentation zones are anticipated. The study recommends sedimentation monitoring as a routine component of environmental impact assessments for infrastructure projects in the Lagos lagoonal system. Keywords: sedimentation rates, Badagry Creek, benthic ecology, estuarine impacts, Lagos lagoon