Co-variation of sinking rate and cell quota among nutrient replete marine phytoplankton

Abstract

Relationships between sinking rate (v) and carbon cell-1, nitrogen cell-1, and volume cell-1 were examined for 29 species of phytoplankton. Sinking rates were linearly related to all 3 indices of cells size (P < 0.001). Sinking rates of nanoplankton-sized organisms (i.e. cell volumes < 5,000 1m3) were low, = 0.15 m d-1, and similar among various species. Sinking rates of net plankton (i.e. cell volumes > 5,000 pm3) ranged from 0.23 to 1.70 m d-1. Although the co-variation of v with the carbon and nitrogen cell quotas is coincidental with these quota's variation with cell size, the relation is of practical interest because carbon and nitrogen are frequently budgeted in ecosystem models.