Brookelynn presenting at the Pacific Marine Environmental Laboratory (PMEL) Summer Intern Symposium. Credit: Emily Bryan
Hi, I’m Brookelynn Gotschall, and this summer I had the opportunity to join NOAA PMEL’s Ocean Molecular Ecology Group as an undergraduate research intern under the NOAA Ernest F. Hollings Scholarship. My primary project focused on the urgent environmental challenge of Harmful Algal Blooms (HABs). As ocean temperatures rise, some microscopic algae known as phytoplankton rapidly multiply, causing blooms that release harmful toxins or physically harm animals and humans, making them HAB species. One such organism, Alexandrium catenella, produces lethal toxins responsible for paralytic shellfish poisoning, which can cause symptoms ranging from dizziness and vomiting to respiratory failure in humans.
To better understand where these toxic blooms might strike next, I analyzed a multi-year eDNA dataset collected during multiple cruises in the U.S. Arctic. While eDNA offers a broad look at which species are present, it can't tell us on its own if they are producing toxins. Assessing real bloom risks still requires pairing our genetic maps with separate cell counts and toxin testing, making our eDNA analysis one crucial building block for HAB research.
By pairing these eDNA maps with physical ocean conditions like dissolved oxygen, water temperature, salinity, and depth, we can build early warning tools to forecast future toxic bloom risks. Learning how to process and interpret these large datasets was a huge milestone for me, revealing how ocean factors like falling oxygen and warming water shape marine communities. Specifically, my analysis showed distinct shifts in samples that contained the target HAB species, with certain species spreading further north alongside an overall rise in Arctic water temperatures.
The urgency of this work also hit close to home. In fact, while analyzing eDNA data from the U.S. Arctic, active HAB events were happening right here in Washington state, triggering emergency beach closures across the Hood Canal. My project showed how eDNA serves as a vital starting point. By pairing eDNA with oceanographic drivers, we can build early warning tools to safeguard commercial fisheries, protect Indigenous subsistence food security, and prevent public health crises.
Beyond data analysis, I also gained invaluable hands-on field and laboratory experience. A personal highlight of the summer was a trip to Vashon Island, where I collected and photographed a nudibranch (sea slug) that was originally thought to represent a new species of the genus Doto. Back in the lab, I performed tissue extractions and ran a lab technique used to make millions of copies of a specific DNA segment called PCR to help determine if these sea slugs are genetically distinct from known populations. Sequencing unveiled that this Vashon specimen was in fact Doto amyra, a known species from the region.
Working alongside the OME team at NOAA’s Western Regional Center in Seattle has been an unforgettable experience. Whether I was coding at my desk overlooking Lake Washington, processing DNA in the lab, or searching for nudibranchs, this summer expanded my skills as a scientist and deepened my passion for ocean conservation!
