Marine snow: sinking rates and potential role in vertical flux

The sinking rate of intact marine snow (macroscopic aggregates) was determined in settling chambers on seven occasions in Monterey Bay, California and in the northeastern Atlantic. Sinking rates ranged from 43 to 95 m day ^-1 (average 68 m day ^-1). The average calculated flux from the upper 20 m of the water column was 30.7 × 10 ⁴ aggregates m ^-2 day ^-1. These calculations suggest that from 3 to 5% of the POC (particulate organic carbon) and 4% to 22% of the PON (particulate organic nitrogen) standing stocks were removed from the surface water each day by the sinking of marine snow.