A sudden increase in the abundance of algae or phytoplankton resulting in a contiguous mass of highly concentrated phytoplankton algae in the water column
US Department of Commerce, National Oceanic and Atmospheric Administration, Glossary - NOAA's State of the Coast (SOTC), Washington, DC, USA 2013. http://stateofthecoast.noaa.gov/glossary.html, (CoaStormEmr - Amer) {881}