Cumulative Impacts Assessment to Support Ecosystem-Based Marine Spatial Planning In Kenya

Abstract

It is now recognized that Maritime Spatial Planning (MSP) needs to incorporate spatial information on human impacts. Marine ecosystems are available for multiple uses, and as these uses increase cumulative impacts can have a substantial effect on marine ecosystems and species. To determine the nature of ecosystem vulnerability to specific uses and assess' the effects of cumulative impacts, it is necessary to integrate ecosystem data with spatial and temporal human use data. This requires methodologies that can facilitate the integration of different types of data at different spatial scales for effective decision making. This article developed a spatial multicriteria decision framework that was applied in assessing the cumulative impacts of human activities in coastal and marine ecosystems in Kenya. The aim was to understand how the impacts from multiple threats affected the. marine and coastal ecosystems and how the resulting information could be used for improving MSP and management processes. The analysis utilized expert judgment to characterize the relative importance ofhuman activities in causing adverse impacts on coral reefs, seagrasses, and mangrove ecosystems. It combined the expert judgments with spatial data on human uses and ecosystems to develop a scoring of relative cumulative impacts for each cell in the study area. This methodology identified a number of potentially significant geographical locations of cumulative impacts. Analysis of spatial distribution of cumulative impacts in relation to locations of marine protected areas (MPAs) showed that all of Kenya's MPAs were vulnerable to multiple human impacts in their locality.