Sinking velocities of phytoplankton measured on a stable density gradient by laser scanning.

ABSTRACT: Two particular difficulties in measuring the sinking velocities of phytoplankton cells are preventing convection within the sedimenting medium and determining the changing depth of the cells. These problems are overcome by using a density-stabilized sedimentation column scanned by a laser. For freshwater species, a suspension of phytoplankton is layered over a vertical density gradient of Percoll solution; as the cells sink down the column their relative concentration is measured by the forward scattering of light from a laser beam that repeatedly scans up and down the column. The Percoll gradient stabilizes the column, preventing vertical mixing by convection, radiation or perturbation of density by the descending cells. Measurements were made on suspensions of 15 microm polystyrene micro

SUBMITTER: Walsby AE 

PROVIDER: S-EPMC1578759 | biostudies-literature | 2006 Jun

REPOSITORIES: biostudies-literature