Distribution and Composition of Phytoplankton in San Juan Channel in Fall 2013

Abstract

Phytoplankton are the base of the marine food web. They have a rapid cell growth and reproduction and can produce million of cell per liters of seawater. Phytoplankton account for 95% of primary production. In the San Juan Channel, changes in phytoplankton abundance and composition is interesting because the physical condition of the ocean give dynamics between the nutrients and the plankton. The study site is in the San Juan Channel on the weekly R/V Centennial cruise. Phytoplanktons were collected using 80𝜇n net in 30 m deep water, then preserved in formalin. The top 5 genera for phytoplankton this year are Ditylum, Coscinodiscus, Skeletonema and Asterionellopsis. There are one instance where two out of five genera were abundant and there were some episodic bloom in two events. Overall, this yeat the phytoplankton were abundant over the beginning of fall and decline over the course of the fall quarter.