The Thomas Fire created huge plumes of smoke and ash over the Santa Barbara Channel. That event spurred a local researcher to study the effects of wildfire ash on marine life.
Tanika Ladd was a PhD student at UC Santa Barbara when the Thomas Fire broke out in 2017. She knew that wildfire ash can be toxic in freshwater streams, and she wondered about the ocean.
“We know that here on land all of this ash is falling and accumulating on our windows, on our cars, so clearly this is influencing the ocean, but we didn’t know how or what that meant,” she said.
Ladd said she couldn’t find any research on how ash from wildfires impacts marine life. So, with a team of scientists, she quickly devised a plan for experiments in the lab and out at sea.
First, they gathered ash.
“All of this ash that was collected was from car windshields, so we knew that it had been put up into the atmosphere then deposited again, so we were hoping that was a relatively good representation of the ash that would be falling over the ocean,” Ladd said.
She said they mixed the ash with seawater then filtered out particulate matter. The team studied different concentrations of samples over time.
“We tested the chemistry of that water and we did find that it added a lot of nutrients, mainly in different forms of nitrogen,” Ladd said.
Those nutrients, she said, can promote growth among natural microbial communities that are important to the food web for marine life.
Ladd said the seawater was enriched by the ash and no harmful effects were discovered in this Santa Barbara study, but she said more research on a global scale is needed.
The study is published in Proceedings of the Royal Society B: Biological Sciences.
