A Sunday morning stillness washed over the quaint, foggy town of Avila Beach. Working in an unassuming, gray building at the end of the 3,000-foot-long Cal Poly Pier was lead sampler and biology junior Sydney Yium.
She was absorbed in her work, collecting weekly phytoplankton and water samples for the California Harmful Algal Blooming Monitoring and Alert Program, a research initiative established in 2008. This program collects data from nine university-run or municipal pier stations, spanning from San Diego to Humboldt.
The phytoplankton species samples and water quality data collected by Yium are used to help predict and detect harmful algal blooms, which are caused by certain plankton species releasing toxins into the ocean.
Both the Cal Poly Pier in Avila and the Morro Bay monitoring sites contribute to the work of the monitoring and alert group, which focuses on a species known as Pseudo-nitzschia, which secretes a neurotoxin called domoic acid.
Climate change is only exacerbating these blooms, according to Yium. This work has grown increasingly important, especially in the wake of the marine mammal strandings that have occurred along the central and southern California coastlines in the last few years.
According to the Southern California Coastal Observing System, the magnitude and frequency of these high domoic acid concentrations are increasing, and this year’s algal bloom started earlier than previous years.
In April, Santa Barbara and Los Angeles saw an unprecedented number of domoic acid-linked strandings and deaths. Recently, a minke whale was found dead in Long Beach Harbor with a high amount of the neurotoxin in its urine.
Since phytoplankton form the base of the marine food web, when domoic acid accumulates in smaller species that larger mammals feed on, it has major implications for these higher trophic levels, Yium said.
“It’s just really important to think about the interconnectedness of the oxygen levels and the environmental conditions that cause a bloom, and then what that bloom in turn causes,” she said. “One of the main goals of [the Cal HABMAPs] is to try to discover if there are any triggers that we can preemptively identify.”
Cal Poly associate professor Alexis Pasulka, a Principal Investigator for the Southern California Coastal Observing System, runs the research at the Cal Poly Pier shore station.
Because of the dangerous impact that toxic algal blooms have on human health and food safety, the data collected at the pier receives state and federal funding. The vital research is then fed into larger models that allow early public safety warnings and health advisories to be released.
Pasulka, who first dove into the world of phytoplankton ecology in graduate school at Scripps Institution of Oceanography College at UC San Diego, said the team’s real-time data is an important tool that local businesses can use to help determine any toxicity levels that could be in their catch.
Recently, the CDPH has issued a statewide quarantine of recreational shellfish due to high levels of the toxins that cause paralytic shellfish poisoning.
The Cal Poly researchers also work in conjunction with Morro Bay aquaculturists to help determine whether certain phytoplankton are linked to die-offs that can occur within their harvests, which can be devastating to their business. The California aquaculture industry is an important contributor to the state’s overall economy, according to Pasulka.
Yium’s weekly contribution to larger state research
Closed to the public, the Cal Poly Pier is a highly revered emblem of research for the Center for Coastal Marine Sciences, and provides students and faculty with a hands-on learning environment.
Having been introduced to Pusulka’s research as a sophomore, Yium started working as a sampler at the Morro Bay monitoring sites and transitioned to the role of lead sampler at the Cal Poly pier program last July.
Public safety is a major driver fueling her passion for the phytoplankton research. She said the most important thing for people to remember is that studying the ocean’s microscopic world is important because it has a big impact on the environment and public health.
“Even though phytoplankton are not as cool as sharks or whales, and it’s not something that’s going to blow your mind, it’s still really important to protect those things that you love,” Yium said. “You’ve got to focus on small stuff to get to the big stuff.”
Counting during big algal blooms can be very laborious and time-consuming, as some plankton species make chains of hundreds of cells, Yium said. Honing her phytoplankton identification skills called for two months of training.
During a recent sample, Yium counted 1,900 cells from one species and 1,400 cells from another. “Once I started dreaming about phytoplankton, I was like, ‘Ok, you need to separate yourself,’” she said.
Yium then puts the data from her weekly sampling into an email that’s sent to a subscription list made up of stakeholders, scientists and government officials. This information is released onto the California Harmful Algal Blooming Monitoring and Alert Program website.
She said it can be easy to get lost in the behind-the-scenes research work, going through the steps of sampling and sending out the weekly email. “It took me a long time to realize that people actually use this data.”
Morro Bay monitoring sites
Similar research is also conducted at the Morro Bay harmful algal blooms monitoring sites, which were kick-started during masters student Nicholas Soares’ undergraduate senior thesis in 2020.
What started as a small-group endeavor within Cal Poly’s Coastal Marine Sciences department — spearheaded by Soares — became a joint project with the Morro Bay National Estuary Program to expand research in San Luis Obispo County.
The original site, located at the front of the estuary near the Morro Rock, has since collected years of important data that has been compared to samples from the Cal Poly Pier in Avila Beach.
In January 2023, having onboarded more undergraduate researchers and community volunteers to collect samples, and having created a community project with the estuary program, a back bay monitoring site was added.
“We’re interested in understanding the full community, because we understand that whatever’s going on in the microbial community is going to impact those final results [in the higher trophic levels],” said Soares, whose baseline interest in phytoplankton skyrocketed quickly after joining Pasulka’s research.
In 2017, when Soares was pursuing a marine sciences degree, he stepped into the position of Cal Poly Pier harmful algal blooms sampler — the position Yium currently holds — and held it until graduation, having come to understand that research is the stepping stone to understanding everything else in the ocean.
“The long-term goal is to get to some kind of forecasting,” Soares said. Just like weather forecasting predicts weeks ahead, he hopes with Cal Poly’s continuing data and harmful algal blooms research, they can get to a point where they can foresee these toxin production events.
The largest harmful algal bloom that Yium has encountered since working on the research program was in late March. During a typical school week, she would have had the sampling data published in a timely manner and emailed to those that use her research to inform other scientific studies or ocean farming. However, the bloom occurred during spring break, when most were away.
It had been decided before the bloom broke out, Yium said, that she would collect the samples but wait until school was resumed before sending out the sample data. However, a flurry of chaos flooded Yium’s and Pasulka’s email inboxes, as countless stakeholders and organizations were reaching out with questions regarding the bloom.
It’s in moments like these that Yium is further reminded that her role at the Cal Poly Pier is part of something much larger and more important than most of the community realizes.
“People are really making decisions based on these data, and I think that’s a really powerful realization that sitting at the microscope and making counts mean something to somebody,” Pasulka said.
In the wake of recent budget cut proposals from the Trump administration that have threatened climate modeling and research forecasting systems, Yium, like many others, was met with difficult realities.
“I’m only 21,” Yium said. “I have never really been impacted in my job or my life directly by the administration, it has just (felt) like this foreign entity. I felt so naive beforehand because I’ve never really considered that there’s a possibility that people don’t care about this.”
Billions are set to be cut from agencies that monitor oceans, weather, and the atmosphere, and protect conservation land and national parks. According to the budget overview, $1.3 billion will be slashed from the National Oceanic and Atmospheric Association (NOAA), the effects trickling down into research grants and educational outreach programs.
“It just totally went over my head, and when the possibility came around that we might lose funding, I just didn’t understand,” Yium said. “This is the basis of everything that matters in the ocean. This is why we’re studying this, because it means everything for everything else.”