During December, 2017 a massive wildfire, termed the Thomas Fire, in Ventura and Santa Barbara counties burned over 280,000 acres, prompting severe air quality warnings and initiating a series of debris flow events. During this time, our coastal ecosystem was affected by ash deposition as well as mud input (from both debris flows and intentional dumping). These influences on California coastal marine systems may become more important as the severity and occurrence of fire events in California appears to be increasing. However, the impact of these events on our coastal ecosystem is currently unclear. Thus, our lab is investigating the effects of wildfire ash and mud input on our local marine ecosystem with a focus on phytoplankton physiology and community composition. Seasonal experiments have been conducted with natural SBC phytoplankton communities in incubators providing realistic conditions with constant flowing seawater and natural light at UCSB's marine laboratory to investigate how ash or mud-derived nutrient sources affect phytoplankton communities in different seasons (funded by Coastal Fund, UCSB).