Seasonal Distribution of Phytoplankton Biomass in a Nearshore Area of the Central Basin of Lake Erie, 1975-1976

Author Institution: Great Lakes Laboratory, State University College at BuffaloSamples for the analysis of seasonal distribution of phytoplankton biomass were collected on 10 occasions between July 1975 and June 1976. Samples were taken from 3 depths in the euphotic zone at 5 nearshore stations in Lake Erie near Ashtabula, Ohio. A bimodal pattern of distribution was observed with fall and spring maxima and the dominance of Bacillariophyceae. Although the maxima were equal in magnitude, the fall peak was longer in duration and was dominated by Stephanodiscus niagarae and Pediastrum simplex. The spring biomass peak was observed on a single collection date and was composed principally of Stephanodiscus niagarae, Skeletonema subsalsum, Melosira italica and Cyclotella sp. The Cryptophyta were common throughout the study while representatives of the Cyanophyta and Pyrrhophyta were only abundant in a single collection. The occurrence and distribution of Skeletonema subsalsum (Bacillariophyceae) are discussed