Vat incubator with immersion core illumination — a new, inexpensive setup for mass phytoplankton culture

One of the shortcomings in studies of bivalve grazing has been the difficulty of culturing and making available sufficient quantities of algae. This was overcome using a 250 l capacity vat incubator with immersion core illumination (VIICI) in connection with experiments involving the diatom Nitzschia pungens f. multiseries , which produces domoic acid, the cause of amnesic shellfish poisoning. Nitzschia cultures grown in this incubator yielded maximum cell concentrations of 158-166 x 10 super(6) cells/l, a peak intracellular domoic acid level of 2.0 pg/cell and a maximum division rate of 0.3/d. The VIICI design is ideally suited for laboratory mass culture of phytoplankton, and has potential for wide application in phycotoxin, toxicological and environmental research, as well as for aquaculture.