Effects of quantified small-scale turbulence on the dinoflagellate, Gymnodium sanguineum (splendens): contrasts with Gonyaulax (Lingulodinium) polyedra, and the fishery implication

Abstract

Gymnodinium sanguineum dinoflagellate cultures were subjected to constant staining flows to quantify the threshold level for growth inhibition by viscous streses for this organisms 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 γ as small as 1 rad s⁻¹ and was independent of γ 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 γ ≈ 3 rad s⁻, and growth was prevented entirely above 8 rads 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.