Pigment Characterization of the Giant-Colony-Forming Haptophyte Phaeocystis globosa in the Beibu Gulf Reveals Blooms of Different Origins

Phaeocystis globosa has formed intensive blooms in the South China Sea and even around the world, causing huge social economic losses and environmental damage. However, little is known about the formation mechanism and dynamics of P. globosa blooms. 19′-Hexanoyloxyfucoxanthin (hex-fuco) is often used as the pigment proxy to estimate Phaeocystis biomass, while this is challenged by the giant-colony-forming P. globosa in the Beibu Gulf, which contains only 19′-butanoyloxyfucoxanthin (but-fuco) but not hex-fuco.