Bioluminescence in the Salish Sea Lecture

Photo courtesy of Matt Nichols.

The Community Boating Center (CBC) and Western Washington University’s (WWU) Marine and Coastal Science (MACS) program have partnered to develop a greater understanding of the bioluminescence in Bellingham Bay. MACS student, Lucy Greeley, will be completing her capstone project determining what planktonic communities are responsible for the glowing phenomena in Bellingham’s backyard and how they vary throughout the season.

Greeley hopes to tackle some of these sparkling mysteries through citizen science studies. Guests of the CBC’s bioluminescence excursions will have the opportunity to participate in research by completing plankton tows, collecting light samples, and practice identifying the glowing species using a video microscope. Greeley will then be studying the specific DNA of samples correlated with days with especially bright bioluminescence to determine which species are present and if they carry the luciferase enzyme and luciferin substrate.

Bioluminescence is the process of emitting light through a chemical reaction in a living organism. One of the most commonly known organisms that emit bioluminescence are fireflies. In the marine world, people think of deep ocean organisms like the Angler fish or the sparkling sandy beaches in Mexico. But in fact, right here in the Salish Sea we have stunning bioluminescent plankton throughout the summer months. These plankton emit light when provoked by mechanical stimuli - when waves move through the surface, when a fish swims or when a paddle strokes through the water. This brilliant reaction is emitted by the enzyme luciferase which when binded with the substrate luciferin, in an oxygenated environment, creates light. Research suggests that the most common bioluminescent plankton, noctiluca, are present in the Salish Sea, but lack the substrate luciferin- and thus do not emit bioluminescence. It’s unknown exactly which species cause this brilliant phenomena here in Bellingham Bay.

There are two hypotheses regarding why plankton emit bioluminescence: first that it’s a strategy to surprise predators, or that it attracts secondary predators to locate and eat the predators preying on the plankton. Bioluminescence is incredibly common in the ocean and yet it’s a language with light that we know so little about.