The Effects of Crude Oil on the Marine Diatom, Phaeodactylum tricornutum, Grown in Silica-Enriched and Silica-Limited Conditions

Abstract

This experiment was designed to determine the effects that crude oil and dispersants have on a marine diatom, Phaeodactylum tricornutum. This species was chosen as it has a siliceous frustule, which may increase its resilience to pollutant exposure. We hypothesized that P. tricornutum grown without their siliceous frustule would be more susceptible to pollutants compared to those grown with their siliceous frustule. We analyzed estimated oil equivalents, growth, photosynthetic efficiency, and macromolecular composition to examine the effects of oil and oil and dispersant exposure. P. tricornutum exhibited a high level of robustness in response to WAF and DCEWAF and a high sensitivity to CEWAF. Silica-limitation proved to be a major factor in the sensitivity of P. tricornutum to the oil and dispersants, which can be explained by significant differences in treatments with and without the presence of silica. We found that the effect of oil and dispersants on phytoplankton vary based on the environmental conditions and oil concentrations and that the effects of oil exposure are not always detrimental. These data provide an understanding of the response of this phytoplankton following an oil spill. In future studies, it would be beneficial to expand the parameters being tested to gain more insight into the physiological changes in phytoplankton cells resulting from crude oil exposure.