Conclusions

  1. The monitoring described here was undertaken to document changes in the biological expression of eutrophication, and will continue to be important as management proceeds.
  2. The data illustrate the importance of collecting physicochemical information at the same time as biological data; otherwise interpretation of the biological information is precluded.
  3. The information demonstrates the use of long-term data bases for testing hypotheses in a retrospective way.
  4. While it seemed initially that extreme year-to-year differences might lead to difficulties in data interpretation, the reverse has proved to be the case; the large between-year variance has enhanced our ability to interpret biological events.