Chlorophyll a concentration is widely used as a proxy to describe trends in phytoplankton biomass over spatial and temporal scales. The concentration of chlorophyll a in Storm Bay showed surprisingly little variation across the seasons. There was a gradient in concentration from site 1 to site 3, where chlorophyll a decreased slightly. It was highest and most variable at the inshore sites 1 and 9, and lowest at site 3, furthest out in the bay. There was no clear annually recurrent seasonal bloom, although data suggests higher values in spring and autumn (see later time series).