Call of the light draws Western student to study bioluminescent plankton

Jacob O'Donnell
Office of University Communications intern

Many people think that the ocean’s greatest mysteries are in the depths, but one Western student is searching for them in the shallows of the Salish Sea. 

Lucy Greeley, a fourth-year Marine and Coastal Science major, is studying the bioluminescent plankton in the waters in and around Bellingham Bay this summer. She is working with the Community Boating Center in Fairhaven and her advisor, WWU Associate Professor of Environmental Science Robin Kodner, famous for her work on the pink snow algae in the North Cascades, to collect the plankton and examine their DNA and determine their species. 

A whole kayaking and ecotourism industry is based on the eerie light bioluminescent plankton emit when disturbed by a paddle, a swimmer, or rocks on the shore, she said. 

“Bioluminescence is fascinating and infatuating,” Greeley said. “There’s clearly a reason why it’s happening and it’s not just for our own viewing.” 

Greeley hopes her research can answer the question of what exactly is contributing to the bioluminescence seen in Bellingham Bay. Greeley is curious if one of the species could be noctiluca, which is latin for “night light.” 

Noctiluca are a single-celled type of plankton called dinoflagellates. They are known to be bioluminescent in other waters around the world but maybe not in the Pacific Northwest.

A sign that Washington state’s noctiluca could be bioluminescent is the presence of an enzyme called luciferase and a substrate called luciferin, Greeley said. When luciferin and luciferase combine in an oxygenated environment, it produces a glow. Local noctiluca are proven to have the DNA for it but previous studies have shown they don’t express those genes in this area of the world. 

Greeley said she’s skeptical of these studies because they used samples in a limited number of locations. 

“One of the questions I’m trying to find out this summer is the community composition,” said Greeley. “Who is contributing to the bioluminescence?” 

Greeley’s team, including guests on the CBC’s bioluminescent kayak paddles, collect the plankton using nets dragged behind kayaks. They also collect them by filling one liter bottles with seawater during each kayak trip. The samples are put through a special filter to isolate the plankton and send them elsewhere for DNA analysis, said Greeley. 

 

Thursday, June 30, 2022 - 11:36am
Noctiluca are seen under a microscope in white on a black background.

A sample of noctiluca under a microscope, taken by WWU Associate Professor of Environmental Science Robin Kodner.