HPLC-measured chlorophyll-type pigments during a phytoplankton spring bloom in Bedford Basin (Canada)

Composition of HPLC-analysed chlorophyll pigments was followed during the phytoplankton spring bloom in 1984 in Bedford Basin (Nova Scotia, Canada). Pigment distribution characterized 3 different bloom stages: high concentration and relative proportion of chl a in the early bloom stage, increasing importance of chl a derivatives and pheopigments (both pheophytin a and pheophorbide a) in the late bloom stage, and, after a mixing event, transport of surface pigments to the deeper layers, followed by an increase in pheopigments. These results can be interpreted as a combination of changng physiological condition, grazing and vertical transport. Processes affecting pigment dstribution are discussed and it is suggested that a number of pigment-affecting processes be better identified before pigment indicators are to be used quantitatively.