The publication, in 2000, of the Water Framework Directive (WFD) presented European countries with a new set of obligations to maintain and, where necessary, enhance the ecological status of their surface waters. The directive stimulated considerable funding opportunities for developing the methodologies needed for its implementation. Many new research programs were initiated at this time.

“Our goal, as described in my paper and the others in the special issue, has been to obtain the information and develop the statistical methods needed to allow results obtained from different countries, or different groups of plants and animals, to be presented on a common scale.”

My colleagues and I were fortunate to win a major European Commission contract, the STAR project, to address many of the key questions that needed to be answered. Hydrobiologia kindly allowed us a special edition in which to showcase our results. This has attracted considerable interest from the many other researchers working to help implement the WFD.

As STAR project leader, I was privileged to write the introductory paper that laid the groundwork for the excellent series of individual papers that my partners, from all over Europe, contributed to the special edition.

Our work built on the collective knowledge of aquatic bio-assessment methods of the project team and the published and grey literature from both Europe and the rest of the world. The majority of my colleagues had worked in this area for many years and had well-established research reputations. Others were practitioners in the water industry, with considerable practical knowledge. Many of them co-authored my paper and the success of our project lay in the strength of the team.

We used our knowledge and experience to implement a Europe-wide sampling program to standardize, intercalibrate, and integrate existing national sampling methods for a suite of taxonomic groups that included phytobenthos, macrophytes, macro-invertebrates, and fish. The greatest emphasis of the work was on the use of macro-invertebrates and each of the widely-used European sampling methods were compared and inter-calibrated with the AQEM sampling methodology, developed by Daniel Hering and his partners, in the EC project of the same name.

One of the key topics of our research, led by my CEH colleague Ralph Clarke, was the influence of uncertainty in the use of biological communities for the assessment of ecological status. The project resulted in the development of many databases and bioassessment tools that are detailed in my paper and on the STAR website.

From the beginning of the previous century, European nations have been developing their own national methodologies for monitoring the state of their rivers. They have used the information they gathered to divide streams and rivers into quality classes from excellent to bad. However, the differing methodologies used, the different groups of plants and animals sampled, the errors and variability in the sampling methods, the wide range of biological indices used for assessment and the differing definitions of the quality classes meant that what might be considered a good quality river in one country might only be categorized as poor in another.

Our goal, as described in my paper and the others in the special issue, has been to obtain the information and develop the statistical methods needed to allow results obtained from different countries, or different groups of plants and animals, to be presented on a common scale.

My involvement in this research stemmed from my considerable experience of the use of macro-invertebrates for the bio-assessment of rivers. I was a founding member of the team, led by John Wright, who developed RIVPACS (River InVertebrate Prediction and Classification System) in the UK from 1978 onwards.

RIVPACS introduced the concept of the reference condition approach (RCA) for assessing the ecological status of rivers. Much of the underlying philosophy of the WFD was based on RCA, and the RIVPACS approach has been widely adopted in Europe, North America, and Australasia.

RCA was central to the STAR program but also a potential obstacle because it required agreed definitions of reference conditions. Reference conditions are conditions of use prescribed for testing the performance of a measuring instrument or for comparison of results of measurements. The definitions we adopted are given in my paper and benefited by the work of the AQEM and FAME projects, the latter led by Stefan Schmutz, and from the European Union reference condition working group (REFCOND).

Nonetheless, in many regions of Europe and in the lower reaches of large rivers suitable reference sites could not be found and this limited the range of site types that could be included in our project. We hope to make further contributions to ecological assessments of these other, more problematic watercourses.

Population growth, intensification of farming, increased acid deposition, and climatic changes are some of the pressures that impact on the biological condition of rivers. Consequences include increased nutrient and chemical loads, acidification of water courses, reduced flow and increased temperatures, and the loss of habitat diversity.

It is the role of scientists, like me, to provide effective methods, based on sound and innovative science, for assessing the health of our watercourse and the integrity of the biological communities which they support. Moreover, we need to develop reliable early-warning systems, to detect adverse changes in these parameters. Awareness of, and allowance for, uncertainty in sampling and analytical methods are key to these processes.

It is then the task of water managers to develop appropriate monitoring strategies, built on the knowledge we provide them. In turn, it is the duty of the politicians to provide the policies, legislation, and funding to enable these programs to be implemented and the identified impacts and environmental pressures ameliorated.

In our small way, I believe that the STAR project has addressed these issues and made a significant contribution to the role of the scientist in the overall process.