Biomonitoring as a prerequisite for sustainable water resources: a review of current status, opportunities and challenges to scaling up in East Africa

摘要

Degradation of aquatic ecosystems in the Lake Victoria basin (LVB) and the rest of East Africa has elicited concern because of its bearing on social and economic development. Rapid population growth, industrialization and its associated urbanization, agricultural intensification and habitat loss have increased pressure on the integrity of water resources. Costs associated with traditional approaches to monitoring water quality have become prohibitive while not giving reliable early warning signals on resource condition to aquatic resource managers. The purpose of this paper is to explore approaches to developing macroinvertebrate- and fish-based biomonitoring tools in the LVB and East Africa and the challenges they face through a review of studies that have been carried out in the region. The hypothesis is that aquatic biota in the LVB provides cost-effective and integrative measures of the physical and chemical habitat conditions thus necessitating their use in assessment and monitoring of water resources. In the LVB macroinvertebrate and fish based indices of biotic integrity (IBIs) have demonstrated their utility in identifying sources of impairment, determining the extent of impacts and stand to give natural resource managers a scientifically defensible rationale for developing guidelines for conservation and management. Despite this significant step, however, adoption and use of indices as part of regular monitoring programs are yet to be realized. We recommend for the advancement and adoption of biological criteria as an integrated approach to monitoring human-induced stress in riverine ecosystems of the East Africa region.