The Vertical Flux of Metazoans (Holoplankton, Meiofauna, and Larval Invertebrates) due to Their Association with Marine Snow

We investigated the association of meiofauna (nematodes and harpactacoid copepods), larval polychaetes, and holoplankton with marine snow. Using a sediment trap equipped with a time-lapse camera, we measured the vertical flux of these organisms due to their association with marine snow. On average, 83 and 74% of the nematodes and competent larval polychaetes were on marine snow as were only 15 and 9% of the harpacticoid copepods and precompetent larval polychaetes. On average, 94, 80, and 25% of the vertical fluxes of nematodes, competent larval polychaetes, and harpacticoid copepods were due to individuals on marine snow. The vertical flux of precompetent larval polychaetes was negligible. By inhabiting passively sinking aggregates, nematodes and competent larval polychaetes would deposit on the seabed according to the hydrodynamical processes controlling marine snow deposition. Of the holoplankton (calanoid and cyclopoid copepods, nauplii, and larvaceans), < 2% was on marine snow. Vertical fluxes of calanoid copepods and nauplii were negligible. The vertical fluxes of cyclopoid copepods and larvaceans were large, but only 3% was due to individuals on marine snow.