Volunteers working in conservation schemes are often involved in restoration projects. Yet, due to a lack of standardised monitoring, there is little supporting evidence that biodiversity or ecosystems recover as a result. There is also no suitable citizen science monitoring scheme available for volunteers to assess the ecological impact of their river restorations. Consequently, restoration designs are rarely evidence-based, and their impacts are not evidence-assessed. That’s not to say they are not effective, but rather we have very little evidence to support and help refine future restoration efforts.
Simple colonisation traps can be used to monitor the effects of river restoration, invasive species, and pollution events on ecosystem function. A short section of drainpipe, divided internally in two, is placed on the river bed. Inside each half of the pipe a known weight of cloth paper is placed. A fine mesh placed over the entrance to one half of the pipe excludes macroinvertebrates but allows access by microbes, macroinvertebrates and microbes can gain access to the other half. After 2-4 weeks the drainpipe is removed and the paper reweighed. The reduction in weight of paper gives the microbial and macroinvertebrate decomposition rate and a measure of ecosystem function. The higher the decomposition rate the more energy that is released back into the ecosystem.
Dr Murray Thompson (now with Cefas), Steve Brooks (Riverfly Partnership Chairman)