UBC outreach is shoring up science education on Hornby Island — and having ripple effects
By Geoff Gilliard
On a gloriously sunny day 11 schoolchildren scamper barefoot across a beach on Hornby Island searching for seaweed. Who knew school could be so much fun?
Dr. Bridgette Clarkston did.
“Seaweeds are a gateway into learning and caring about the ocean and coastal biodiversity,” the UBC botany professor says. “They’re so easy to access and it’s such a great excuse to go down to the beach and explore a place where most of us don’t spend a lot of time — even if we live near the seashore.”
Throughout the 2025 school year Dr. Clarkston taught a Hornby Island Community School Grade 7 and 8 class about seaweeds long distance via Zoom, leading up to an in-person visit in May, when she and four of her UBC biology students headed to Hornby for some hands-on learning. The visit was funded by a grant from the UBC Centre for Community Engaged Learning.
“I do a lot of work with my undergraduate students to share their learning beyond our classroom with elementary students,” says Dr. Clarkston, a professor of teaching in UBC’s Biology program. “They could see the immediate impact in sharing their knowledge with new learners. And they loved it.”
Early in the school year, the Hornby Island kids were assigned “seaweed buddies” — specific seaweed species that they learn to recognize over the course of the school year. On beach day they collected and prepared 24 seaweed specimens that are now scientific records in UBC’s Beaty Biodiversity Museum.
There is no high school on Hornby Island. Once the children get to Grade 8 they’re bussed to the nearest high school in Courtenay on Vancouver Island, a daily two-hour, two-ferry commute each way. It’s quite a slog. Some families choose to leave the island when it’s time for their children to go to high school. Others home-school or make billeting arrangements for the kids to stay with friends or family closer to the school during weeknights.
“My class is an extension of the elementary school so we don’t have access to a science lab or anything like that,” says teacher Yakotsenhtha Heather Royal, who teaches the split Grade 7, 8 and 9 class. “When things in their education are missing, it’s really hard for parents and students to opt to stay on Hornby Island until, say, Grade 10.”
Forests of the sea
Seaweeds are a subset of algae. The many thousands of species worldwide are classified into three branches of the seaweed family tree of life — red, brown and green. Seaweeds photosynthesize and are foundational to coastal marine ecosystems, but the three branches evolved independently. Red and green seaweeds are grouped together with land plants like mosses and vascular plants — brown seaweeds are related to microscopic algae called diatoms.
“We’re very lucky in this part of the world because there’s an overlap where two iconic kelp species live — bull kelp, Nereocystis luetkeana and giant kelp, Macrocystis tenuifolia,” says Dr. Clarkston, who specializes in seaweed biodiversity. “Think of these two ‘canopy-forming’ kelp as the redwoods or Douglas-fir trees of the underwater forest, reaching from the seafloor to the water’s surface, creating a three-dimensional underwater habitat.”
Coastal B.C. is a diversity hot spot hosting over 600 species of seaweeds. But climate change is driving drastic declines. Summer sea surface temperatures of the inner Salish Sea are hitting 20 or 21 degrees Celsius. That’s about six degrees too hot for some kelp to grow.
“We’re seeing declines in some kelp species in British Columbia for a number of reasons. In some areas, in particular the inner Salish Sea between Vancouver Island and the mainland, warming waters may be one of the biggest drivers of this loss,” Dr. Clarkston says. “Bull kelp used to be quite abundant in the waters near Hornby Island and my hometown of Comox. Now they’re gone.”
The day after last May’s beach walk, Hornby Island students hosted a public shoreline walk with family members and other islanders.
“Some of the community members who’ve lived on the island for years remembered when there used to be kelp forests,” Dr. Clarkston says. “Other folks who are involved in the seaweed restoration efforts came to learn more about what other species are found on the island.”
Seaweed School serendipity
For the past 10 years, Dr. Clarkston has been running public workshops through the Raincoast Education Society in Ucluelet, B.C. on the outer coast of Vancouver Island. Entrepreneur and seaweed advocate Elizabeth Sheehan, a volunteer steward with the Hornby Island Natural History Centre, met Dr. Clarkston at a workshop and invited her to bring seaweed education to Hornby Island.
“I just loved how Bridgette approached her teaching, and I felt it was really compelling,” Ms. Sheehan says. “Here was this underappreciated member of our intertidal coastal life, and Bridgette brought so much spark and curiosity to it. I thought, we need to learn how to care for our local seaweeds — especially at this time of ecological instability and climate change — and do that in a local way.”
Since it opened its doors in 2009, the Natural History Centre has built a strong relationship with the Hornby Island Community School which is right next door.
“The Natural History Centre came to me as a new teacher because a pilot program had just been launched to keep Grade 8 students on the island for school for one year longer,” Ms. Royal says. “We were discussing ways that we could work together and they came up with the idea of seaweed focused curriculum.”
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“Seaweed School became a win-win,” says Ms. Royal. “It helps Bridgette with community outreach, the Natural History Centre gets to make connections with the community, and the students get to shine within their community. And as a teacher, I get to see the wealth of this knowledge that weaves into our curriculum, but surpasses things that you simply can’t do within the confines of the classroom.”
Museum pieces: a pressing issue
Accompanying Dr. Clarkston and her UBC Science students to Hornby Island for beach day was Keelie Taylor, a curatorial assistant at the Beaty Museum. Taylor, who tends the museum’s algal herbarium, set up a mobile pressing station to preserve museum-quality specimens.
“The Beaty Museum really pushes community outreach because so much of our collection comes from citizen scientists,” says Ms. Taylor. “We work with researchers and academics, but we also have a lot of people that come in as volunteers and work on our collection.”
On beach day, Ms. Taylor and the UBC Science students kept a spreadsheet for the collection data: where a specimen is from, who collected it when, and who identified it. Without consistent year-after-year baseline data it can be hard to know if species have disappeared, or if invasive species have been introduced. All of the seaweed specimens collected that day have the students’ names on the labels and serve as snapshots of the biodiversity of Hornby Island in May 2025.
Pressing seaweed is similar to pressing a flower, but uses thicker, more absorbent layers because of the seawater specimens contain. Special archival-quality paper is used that won’t degrade the specimen or yellow as regular printer paper might, since it’s not acid free.
“We want specimens that will still be of good quality 100 years from now,” says Ms. Taylor. “You want the features of interest to be visible. You want it to dry quickly and evenly, and you want it pressed so that it’s not going to catch or come off the page.”
The pressed specimens are attached to the paper with herbarium glue which can be reactivated with water, making it easier to lift the seaweed from the paper so it can be studied under a microscope or have DNA samples extracted.
As well as teaching Hornby Island students about seaweeds from a Western scientific perspective, Seaweed School adds Indigenous ways of knowing to the lessons.
“I’m from the Bay of Quinte Mohawks in Ontario, part of the Haudenosaunee and the Confederacy of Six Nations,” Ms. Royal says. “We’re not surrounded by ocean so I’ve had to do some research in terms of Indigenous knowledge. The Haudenosaunee look at all of creation as relatives — so here’s a seaweed relative that we haven’t paid much attention to.”
One of Ms. Royal’s goals going into the project was to learn alongside the kids.
“Generally, teachers like to be the authority on something. What I know from my Indigenous elders is that one of the beautiful places to be is in a place of humility. Just say: I don’t know. Let’s go on a journey together.”
Now in its second year, Seaweed School’s current theme is “the secret lives of seaweeds.” Dr. Clarkston, though, has plans to ensure the importance of B.C.’s seaweeds isn’t a secret. She has a dream to work with curriculum designers in UBC’s Faculty of Education to get seaweed education into B.C.’s K-12 classrooms in a more formal way.
“To me, it makes sense for everyone in British Columbia to be aware of seaweeds just like they learn about salmon. I want all kids in this province to learn about the roles seaweeds play in our coastal marine ecosystems and in our lives, from creating habitat for economically and culturally important fish species to contributing to the oxygen we breathe.”
Gardening with dirty undies
Alongside Western science and traditional ecological knowledge, community involvement makes up the third strand of Seaweed School’s “braided lens” approach.
Seaweed fertilizer does what common farming practices no longer do — help rebuild and regenerate soil through enhancing its microbiological activity and adding essential nutrients. It’s a common method used at Hornby Island’s community garden where clinical herbalist and Seaweed School collaborator Angela Willard guided the students through a project called Dirty Undies.
“The dirty underwear test is a way to gauge the microbiological activity of your soil, and demonstrate the connection between the health of soil and seaweed,” explains Ms. Willard. “You bury 100 per cent cotton underwear in your garden and the faster the underwear rots, the healthier the soil — because it’s biodegrading the cotton. Usually the underwear is buried for a 60 day window. We chose to do 90 days because we took into account the winter months are cooler, so the microbial activity is a little bit slower.”
Late last winter, three plots were set aside in the Hornby Island community garden to run the Dirty Undies test. On the first plot only leaf mulch was applied — the control treatment. On a second plot, large amounts of seaweed were stacked in piles on the soil in the traditional way. The third plot was dosed with seaweed tea, concocted by adding seaweed to a water base and letting it “steep”. As the mixture ferments, seaweed nutrients are extracted and enhanced in the tea.
The goal of Dirty Undies is to see which pair of underwear buried in the three plots breaks down fastest. Seaweed tea requires much less seaweed than mulch. If the tea plot wins out over the other two, it could reduce the amount of biomass removed by gardeners from Hornby Island beaches, allowing the seaweed to remain and replenish the habitats.
At the end of the experiment, there was a bit of cotton left in the control treatment, and a tiny bit left in the stacked seaweed treatment. No cotton remained in the seaweed tea treated undies.
“Everyone in our school wrote down which test plot they thought would decompose undies the fastest and why,” says Ms. Royal. “It created natural enthusiasm in the community garden to engage with the scientific method. It’s one of the ripple effects Seaweed School has — now we’re rippling into the community gardeners.”
“I’m the luckiest teacher in the world to have these experiences.”
