Community structure analysis of Bellingham Bay phytoplankton

Our understanding of phytoplankton community ecology is limited in Bellingham Bay. Phytoplankton serve a fundamental role in marine ecosystems as the primary producers that create the foundation of marine food webs. These microorganisms are of great importance to the overall health of these ecosystems and should not go unnoticed. Bellingham Bay provides a unique ecosystem to examine the effects of environmental inputs to phytoplankton community structure. It receives saltwater inputs from the ocean and also has a significant freshwater input from the Nooksack River. Additionally, the bay is known for a seasonal onset of hypoxia near its center during the summer. Our study aimed to understand the dynamics of phytoplankton community structure in relation to depth and environmental heterogeneity. In order to accomplish this, we sampled three sites of varying water quality across the bay at three depths of the water column. Through microscopy and flow cytometry we found that community structure is complex and dynamic from week to week. Communities present in the water varied more between depths than across sites, indicating the sites themselves are more homogenous then we originally believed. Oscillating patterns between the dominance of diatoms to dinoflagellates developed throughout the study and may be related to freshwater nutrient pulses from the Nooksack. Furthermore, this oscillation was noted between large and small cells and may also be related to the nutrients present in the water. DNA and nutrient analysis will provide a more concise look at the interactions seen during the study.