Phytoplankton of the York River

Abstract

Abstract The York River possesses a diverse phytoplankton community represented by a variety of algal species that includes both freshwater and estuarine flora. The mean annual monthly range of abundance is ca. 5–20 X 106 cells L−1 with an extended bi-modal pattern that begins with an early spring diatom peak (March) that declines into early summer. The development of a more diverse representation of taxa in the summer results in a secondary late summer-early fall peak. Diatoms are the dominant phytoplankton component throughout the entire estuary including a variety of pennate and centric species such as Asterionella formosa and Aulacoseira granulata. Dinoflagellates are more common and abundant in the lower segments of the York River where they have been associated with re-occurring and extensive “red tide” blooms. These include Cochlodinium polykrikoides, Heterocapsa triquetra, Heterocapsa rotundata, Scrippsiella trochoidea, and Prorocentrum minimum. Cynobacteria, commonly referred to as blue-green alg...