The Effect of Kelp Shading on Phytoplankton Production

Abstract

Phytoplankton production under the kelp (Ecklonia maxima) canopy was compared with phytoplankton production in open water using the 14C-labeling technique with in situ incubations. A large difference in production rates was found. Under the canopy, production is reduced by an average of 95%. Using this figure it was calculated that canopy shading reduces total phytoplankton production in the kelp zone by about 12%.