EFFECTS OF QUANTIFIED SMALL-SCALE TURBULENCE ON THE DINOFLAGELLATE, GYMNODINIUM-SANGUINEUM-(SPLENDENS) - CONTRASTS WITH GONYAULAX-(LINGULODINIUM)-POLYEDRA, AND THE FISHERY IMPLICATION

Gymnodinium sanguineum dinoflagellate cultures were subjected to constant straining flows to quantify the threshold level for growth inhibition by viscous stresses for this organism and to compare its response to that of a red tide species Gonyaulax polyedra previously studied. Growth inhibition of Gymnodinium was detected at rates-of-strain-gamma as small as 1 rad s-1 and was independent of gamma in the range 1-40 rad s-1. Growth was delayed for 2-5 days, but not prevented entirely. For Gonyaulax, growth inhibition began for gamma almost-equal-to 3 rad s-1, and growth was prevented entirely above 8 rad s-1. The fishery implication is that the apparent necessity of calm seas (Lasker Events) for the growth of larval northern anchovies may not be due to turbulence inhibition of their Gymnodinium food supply.