Chris Ikeda, SFSU RTC

Mission Scientist, San Francisco State University Romberg Tiburon Center

Bio: I’m originally from Vancouver, WA, and obtained my B.S. and M.S. degrees from San Francisco State University (SFSU). As an undergrad, I worked as a research assistant at the Cellana algal biofuels research facility in Kailua-Kona, HI, then returned to SFSU to finish my degree and start my masters research under the supervision of Dr. William Cochlan at the Romberg Tiburon Center (RTC). I developed my expertise in toxic algae at the Friday Harbor Labs on San Juan Island, where I examined the factors responsible for the growth and cytotoxicity of a fish-killing phytoplankter Heterosigma akashiwo. I’ve been to sea before, during a 2014 cruise off the U.S. west coast aboard the UNOLS Research Vessel Melville. I’m joined on this cruise by two other graduates of the Cochlan Phytoplankton Ecophysiology Lab (and longtime colleagues): Brian Bill (NOAA NWFSC) and Julian Herndon (NOAA PMEL).

What I’m doing on this cruise: Brian Bill and I will be studying how a variety of environmental Chris Ikeda in Hawaiifactors– temperature, salinity, light and ocean pH – affect the success and toxicity the harmful algal bloom organism, Pseudo-nitzschia.  This phytoplankton caused millions of dollars of economic loss to the US west coast in 2015 (and 2016) through the closure of razor clam, Dungeness crab and rock crab harvest, and also poisoned numerous marine mammals. We want to understand why the 2015 bloom was so severe, and why Pseudo-nitzschia has been so successful lately.  We’re excited to be testing the role of environmental factors on natural populations of Pseudo-nitzschia in the “real world”, as most of these types of experiments are usually performed in the lab with cultured populations. The knowledge we gain will support the development of predictive models of Pseudo-nitzschia growth and toxin production that will help managers safeguard commercial and recreational fisheries along the North American west coast.

I’m working collaboratively with Brian Bill (NOAA-NWFSC) to examine the environmental factors (including ocean acidity) controlling the growth and toxicity of harmful algal bloom (HAB) species, specifically species of the toxigenic diatom Pseudo-nitzschia. During 2015, a massive bloom of these diatoms extended from the Channel Islands off Santa Barbara to the Aleutian Islands in Alaska, and resulted in the largest recorded outbreak of the neurotoxin, domoic acid (DA), along the North American west coast. Elevated toxins were measured in numerous stranded marine mammals, and resulted in geographically extensive and prolonged closures of razor clam, rock crab, and Dungeness crab fisheries and thus severe economic losses. To date, scientists have suggested that this massive toxic outbreak was initiated by anomalously warm ocean conditions, although other environmental factors were not tested in 2015. During this research cruise, Bill and I hope to rectify this serious deficiency in our knowledge of HAB development by studying how temperature, salinity, light ocean acidity (pH), and nitrogenous nutrients affect the growth and toxicity of the dominant Pseudo-nitzschia species.

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