Introduction to the short communications

Abstract

The shift in phytoplankton community structure towards an increased proportional abundance of cyanobacteria∗ has wide‐ranging ecological as well as water management implications. Certain species, typically representatives of the genera Ana‐baena, Aphanizomenon, Nodularia, and Nostoc, can fix gaseous nitrogen and their rise to dominance within the community can result in a major input of new nitrogen to the ecosystem. Most bloom‐forming species consist of long trichomes or large colonies which may inhibit grazing by zooplank‐ton, and dominance by these forms may reduce the transfer of carbon and energy through to higher trophic levels. Bloom‐forming cyanobacteria contain gas vesicles within their cells which allow them to float to the top of the water column, and their sudden and striking appearance at the surface during conditions of low water turbulence often creates public concern. Cyanobacteria can additionally produce unpleasant tastes and odours in drinking water by releasing volatile organic substan...