Comparing growth rates of natural phytoplankton communities to laboratory culturing experiments

Senior thesis written for Oceanography 445

[author abstract] In a world facing ever-increasing atmospheric carbon dioxide, understanding the various facets of the carbon cycle is critical. In temperate coastal systems, diatoms play a key role in the carbon cycle by contributing to the biological pump that sequesters carbon into deep ocean sediments. Many scientists use culturing experiments to make predictions about the responses of phytoplankton to environmental changes. But do these highly controlled laboratory studies serve as realistic proxies for environmental responses? This study investigated growth rates of phytoplankton communities from Trevor Channel within Barkley Sound, British Columbia using field and laboratory experiments. The similar growth rates in the laboratory experiments imply that diatom isolates maintained in culture for generations accurately reflect the physiology of more recent field isolates.

University of Washington School of Oceanography