Fluorescent Love

WWU environmental science major shares her love of tide pooling.

A fluorescent anemone // photo by Linnea Hoover

by Linnea Hoover

By the light of her headlamp, Western Washington University environmental science major Alyssa Tsukada picks her way across the rocky beaches of Bellingham Bay to the ecological treasure laid bare by the pull of the moon: tide pools.

The tide is at its lowest point in the past month, making it easy for Tsukada to find anemone.

The fluorescent anemone are a fan favorite of friends who join Tsukada on her tide pooling adventures. There’s actually a bit of a waitlist for the opportunity to go tide pooling with Tsukada. She has found that tide pooling is a great educational opportunity that she loves sharing with others.

“Whenever you take people out they just become little kids again,” Tsukada said. “And it’s quite funny, because they’re little kids you can trust to not hurt themselves.”

While the glowing anemone are a highlight of tide pooling for Tsukada and anyone she brings with her, one of the main reasons she goes tide pooling is for their food source: phytoplankton.

The anemone glows neon under her blacklight — otherworldly and alien.

Anemone can re-emit light that they obtain from external sources almost immediately according to the Vancouver Aquarium. Many anemone can use light captured by external sources but can’t create their own. This is called fluorescence. Some creatures are able to create light through an internal chemical reaction which is called bioluminescence.

She strokes an anemone that doesn’t fluoresce with her finger. It sticks like velcro, trying to hold on tight to her finger. This is an attempt to inject venom into what it assumes is food, but humans aren’t in any danger from these anemone according to Tsukada. We’re just too big, and our skin is too thick for these anemone to do any damage.

The anemone sways with the gentle roll of the waves as Tsukada explains the difference between the different types of anemone.

“There are moon anemones and then aggregate anemone, but those are my favorite because those are the ones that fluoresce,” Tsukada said. “And the reason why they are able to do that is because they have that symbiotic relationship with the phytoplankton in them.”

Tsudaka’s research focus at Western has been on marine phytoplankton which can be used as sensors for climate change. She has always had an interest in biology and ecological systems and how they relate to climate change.

“I specialize in diatoms which are a type of phytoplankton that create these silica glass houses around themselves, and they are absolutely stunning,” Tsukada said. “They come in all of these shapes and sizes and functionalities. And they’re just absolutely everywhere.”

AlDiatom under a microscope // photo by Alyssa Tsukada

According to an article in Frontiers in Marine Science,“Understanding Diatom Cell Wall Silification — Moving Forward,” the basic essence of diatoms is that they are “mineral utilizing plants.”

Knowing how diatoms relate to other organisms within tidal regions and the marine ecosystem is really important to Tsukada and inspires much of her work.

Studies have found diatoms to be excellent indicator species for warming water and climate change. Researchers study the skeletons of phytoplankton blooms on lake and ocean floors. The phytoplankton are sensitive to temperature changes and their carcasses last indefinitely at the bottom of the ocean, making them perfect subjects of research for Tsukada and other students and scientists.

When she comes home from tide pooling, Tsukada will often return with water samples that contain diatoms. She lets the water incubate on the windowsill with the lid popped off so that the phytoplankton can off-gas. Tsukada doesn’t want them to suffocate.

Then she waits — letting the diatoms incubate, bloom and multiply. Tsukada says it takes about a week for a good phytoplankton bloom.

“I’ll look at it under the microscope to see like who’s hanging about,” Tsukada said.

Tsukada keeps a microscope on her kitchen table and will sometimes photograph the results of the incubated phytoplankton. Surprisingly, her roommate doesn’t mind the jars of sea water, or the microscope.

“She doesn’t mind at all,” Tsukada said. “I think it’s really funny. She lets me have my microscope out on the table 24/7.”

The phytoplankton that Tsukada captures bioluminesce in the summer months — something regularly witnessed at the end of August and beginning of September at the popular local hangout Teddybear Cove.

While anemone and phytoplankton are common but enjoyable creatures for her to find, one creature Tsukada is on the hunt for is a nudibranch.

“There’s, specifically, a hooded nudibranch that is native to this area,” Tsukada said. “It is this pale, white-like, slug-type of thing that has this billowing appendage that it shoots above its head. It’s like a little astronaut-space-balloon type of creature. It’s super alien.”

The moon and the tides affect Tsukada’s ability to look for the nudibranch, which appears seasonally. The Salish Sea is on a mixed diurnal and semidiurnal tidal pattern, meaning that, depending on the time of year, there is a mix of one to two high and low tides daily.

The moon controls when the tide will be low enough for tide pooling.

“It’s at the half moon stages when the tides are no good,” Tsukada said. “You don’t get a low tide, they stay pretty lame… The zero moon is when they’re the best.”

According to Tsukada, it’s best to plan to go tide pooling when there is an extremely low tide. This gives tide poolers time to safely make their way back up the beach before they are trapped by the water and tide.

Tsukada started tide pooling in 2019 at the invitation of a friend.

“They were part of the Fairhaven program and their oceanography class was going out and they invited me,” Tsukada said. “So, my friend and I went because they were like, ‘Oh my gosh, this is right up your alley.’”

Tsukada tide pooling // photo by Linnea Hoover

Now, Tsukada goes tide pooling at least once a month. She has found that every time she goes out, there is something new to discover and something new of which to be in awe.

“Tide pooling is one of those things where it started as something that was just really fun to go do,” Tsukada said. “I think my work here at Western is just really spurred on by my passion for the environment — and it all starts with just being excited and appreciating what you have around you.”

Click here to watch Hoover’s video about tide pooling.