Here’s a reason to renew your Downeast Magazine subscription for the coming year: Sometime next spring you may be able to read an article on phosphorescence in Castine Harbor. And you just might catch a glimpse of me, my wife Kathy, and four chosen others (selected for their photogenic qualities) to be background filler for the photos accompanying the article.

I’m sure it’ll be a fine article, and I’m glad another writer has twigged into this awesome nocturnal phenomenon.

But wait until you see the pictures that will accompany the article! The star of the show is Karen Francoeur (yes, it’s always about Karen), who owns Castine Kayak Adventures. On Friday nights she offers a phosphorescence tour from Dennett’s Wharf featuring the minuscule dinoflagellates that, when disturbed, emit a glow reminiscent of submerged fireflies. These tiny plankton multiply as the season progresses and the water warms. By this time in the year they’re hanging around by the millions just waiting for someone to come along with a paddle and give them a push.

And when that happens the water comes alive with a blue-greenish, twinkling glow that reminds me of the sparkling trail left behind by Walt Disney’s Tinkerbell as she flies. The display is whimsical yet awe inspiring as you sweep your paddle through the water.

A writer for Downeast decided to explore the phenomenon after reading Francoeur’s brochure describing the Friday night phosphorescence tour she offers, and signed up to check out for herself just what this stuff was all about. Inspired, she decided to write about it and have a photographer come to Castine to capture the essence of the moment in hopes of having Downeast Magazine publish the piece next year. That’s where we, the window dressing, came in. Francoeur conscripted us to come along and be the “other” boats in the picture as the photographer, Tom Zelong, focused on her.

Carolyn Brouillard, the one-woman back office staff and half-owner of Dennett’s Wharf Restaurant, and her daughter Sasha volunteered. And a lucky vacationing couple from Manhattan, Margaret Milnes and Matthew Stuart, won the other two seats on our magical mystery tour. Our five-boat flotilla (my wife and I hopped in a tandem kayak) was armed for the shoot. Castine’s glass-smooth harbor reflected the nearly full rising moon, Mars, and moored sailboats as we attempted to look like tourists (or ducklings depending on one’s perspective).

The photographer stationed himself on the Castine Yacht Club dock and had us paddle v..e..r..y….s..l..o..w..l..y past as he fired off shots while instructing us not to look at the camera and to look like we were having fun.

“Great! Now stay right there” (we’re on an incoming tidal current with a breeze at our backs!) “Now, back up! Maybe you should go around and come by again, s..l..o..w..l..y.”

We’re paddling backward, trying not to swat at the pack of mosquitoes settling in on exposed skin for an evening snack.

“Don’t look at the camera! Look over there! Go S…L…O…W…E…R!”

We were paddling backward again.

“Let’s try two boats in front, the tandem in the middle and two boats behind! Karen, you paddle in here closer to the dock!”

“Around again! S….L….O….W….E….R!”

We start singing “Kum Ba Ya” and swatting mosquitoes while half-heartedly trying to suppress giggles.

Then we opted to try a star pattern with all our bows touching. More “Kum Ba Ya.” More swatting. A truly unruly group.

I’m not sure whether the photographer ran out of film or was bleeding to death from the bug bites (it was getting dark), but our photo shoot ended when the light ran out, and we were released to paddle off in pursuit of phosphorescence. But not before retrieving a helium-filled balloon that floated down from the sky and lighted on the water nearby. We decided to give it to a young girl on a sailboat whose family had come across the bay from Belfast. In return, some of us accepted freshly toasted Marshmallows the family was cooking over a charcoal grill hanging off the stern of their sloop.

By then it was time for us to paddle to a cove upriver to disturb some dinoflagellates and watch some bioluminescence. Darker is better for this visual treat. And what a treat it was. We paddled through huge colonies that shed their light on us as we passed. The most awesome display was in the sea grass near shore where just the slightest movement of the grass got the greenish glow going.

To explain this phenomenon for you, I did a little search on the Web and found some great information at the site for Scripps Institution of Oceanography, a graduate department of the University of California, San Diego. If you check out http://siobiolum.ucsd.edu/Dinointro.html you’ll find some great information.

Such as: “Dinoflagellates are the most common sources of bioluminescence at the surface of the ocean. Dinoflagellates are unicellular protists – 90 percent of all dinoflagellates are marine plankton.”

And this: “The dinoflagellates are also known as Pyrrhophyta, meaning ‘fire plants.’ Some species produce bioluminescence, which is light produced as a result of a chemical reaction within specialized structures in the dinoflagellate cell. Agitation of sea water containing dinoflagellates will stimulate light flashes…”

And here’s what they say about that green-blue glow: “Bioluminescence acts as a burglar alarm. When the cell is disturbed by a grazing predator, such as a copepod (the burglar), it gives a light flash (the alarm) which lasts 0.1 to 0.5 sec. The flash attracts a secondary predator, such as a small fish (the police), which closes in looking for food. The fish is more liable to find and eat the larger copepod than the minuscule dinoflagellate cell. In this way the predators of the dinoflagellate are removed. When the copepod sees the luminescent flash, it gives a jump, because staying put means it is vulnerable to predation. The result is that the feeding behavior of the copepod is disrupted and less dinoflagellate prey are consumed.”

Copepods (meaning oar feet), I learned from the Web site, are small (most are less than 1 millimeter long), shrimp-like crustaceans that swim in seas, lakes, and ponds. Copepods are important in the food web since many animals eat them. Copepods eat bacteria, diatoms, and other tiny, single-celled organisms in the water. Free-swimming copepods are a component of zooplankton and are eaten by many organisms, including mussels, fish and fish larvae, squid, sea birds, and mammals (like baleen whales and some seals).

So there you have it, the food chain in a clamshell and illuminated in the dark waters of Castine Harbor. I have found through experience (and confirmed it on this site) that these little light bulbs reach their maximum light potential about two hours after dark.

One final word from the Scripps Institution of Oceanography: “Dinoflagellates are the most common sources of bioluminescence in the surface waters of the ocean. The light displays created by breaking waves, swimming fish, or boats are mainly due to dinoflagellates. The taxonomic composition of luminescent dinoflagellates will vary with location and time. In the San Diego area dinoflagellates are present year-round; in the Northeast U.S., the combination of short day length and cold water temperatures forces cells to overwinter as cysts in the sediment. In the spring, the warmer temperatures and longer days allows cysts to excyst, forming motile cells once again.”

Jeff Strout can be reached at 990-8202 or by e-mail at jstrout@bangordailynews.net.