Persistence of Macroinvertebrate Communities
Introduction
This projects aims to increase our understanding of long term patterns in macroinvertebrate community structure within catchments.
Summary
The 20th Century saw a proliferation of techniques that use biological indicators as a measure of water quality and environmental health. The development of such techniques was fuelled by the need to assess ecological conditions when making regulatory, stewardship, sustainability or biodiversity decisions that have a strong scientific basis.
When assessing the status of water bodies using techniques based on biotic indices the inherent natural variability of communities presents a considerable challenge to practitioners. Natural variability combined with sampling error may lead to misclassification of the ecological status of sites with significant implications for management practices.
This study takes as its primary focus assessment techniques based on macroinvertebrate communities. Using long term data collected as part of the Environment Agency´s routine monitoring programme the study will look at long term patterns in macroinvertebrate communities within catchments.
Principle Resources and Questions
Data for this study will be taken from the BIOSYS database maintained by the Environment Agency for England and Wales. The database contains information from over 200,000 samples collected as part of routine and targeted sampling from in excess of 60,000 sites. This sample sites are distributed across England and Wales. Samples were collected using a standardised technique and subjected to quality assurance. As such this dataset represents an almost unique record of data collected over a wide geographic region for a period of up to 30 years.
This resource will be used to address the following questions;
Do long term trends in macroinvertebrate community structure vary uniformly across a catchment or are some communities inherently more variable in their structure than others?
What are the underlying reasons for any observed patterns?
What are the implications for biomonitoring?
Approach
The first stage of this study will be to establish criteria for the selection of sampling data from BIOSYS database. These criteria will include availability of species level data, number of samples taken at a specific site, availability of supporting physicochemical data, etc.. Once sites have been selected changes in community composition at sites within catchments will be assessed using measures of similarity such as Jaccards Index. Long terms patterns in community structure within catchments will then be examined using Geographical Information Systems.