Lunar cycle of zooplankton biomass in subtropical waters:: biogeochemical implications

The relationship between zooplankton biomass and moon illumination has been studied north of the Canary Islands. Biomass was significantly greater during the second quarter of the moon's cycle, and decreased dramatically after the full moon in all the size classes of mesozooplankton. The pattern was similar to that described in lakes and confirms the existence of this phenomenon in the sea. This lunar cycle in zooplankton could account for a rather large percentage of the gravitational flux and may help to explain the periodicity in the sinking flux observed in sediment traps in subtropical waters.