A retrospective appraisal of the importance of high-resolution sampling for harmful algal blooms: Lessons from long-term phytoplankton monitoring at Sherkin Island, S.W. Ireland

The ongoing Sherkin Island Marine Station phytoplankton monitoring programme began in 1978. The present stations were established in 1980. Surveying has been carried out continuously since then, employing a more comprehensive sampling strategy than the few other published long-term records. Examples are presented here of cell concentrations for several HAB species and other bloom species from the Sherkin Island record. These show far more short-term and long-term natural variation in time and space than might be expected from the other records in the literature used to investigate HAB, suggesting that ecological complexity may be critically misrepresented in such investigations. This has serious implications for scientists evaluating reports of past HAB (what cell densities were responsible?) and predicting future HAB. Evidence presented here also suggests limitations that should be recognized in using cell concentrations from plankton in models for predictions of HAB.