Zooplankton sinking rate

Sinking rates of solitary phytoplankton cells are only about a meter per day (Smayda, 1970). Particles that sink this slowly require over a year to reach the benthos of the relatively shallow continental shelf, and ten years to reach the abyssal ocean floor. Given the rapid rates of microbial decomposition of organic material in the ocean and the abundance of zooplankton grazers, it is virtually impossible for such a slowly sinking particle to reach the seafloor. 

Numerous mechanisms have been proposed which contribute to the death rate of phytoplankton endogenous respiration rate, grazing by herbivorous zooplankton, a sinking rate, and parasitization (27). The first three mechanisms have been included in previous models for phytoplankton dynamics, and they have been shown to be of general importance. 

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