MERRITT ISLAND, Fla. - Glowing green waves lapped against the spoil-island shoreline, glimmering like Day-Glo paint in the darkness.
And mullet, minnows, crabs and other critters generated glittering illuminated trails as they darted across the Banana River flats, resembling underwater bottle rockets.
"It's like fairy dust. It's amazing!" Sanford kayaker Jane Goddard said, scooping iridescent water from the river and letting it pour through her fingers.
"It sparkles. It makes you feel magical, like pixie dust," Goddard said.
Bioluminescence is stronger and more prominent now across the Indian River Lagoon in north-central Brevard County than the past four years, said Jim Durocher, co-owner of Cocoa Beach-based Space Coast Kayaking.
Why is this water glowing in the dark? Blame billions of Pyrodinium bahamense, a single-cell plankton that emits light when disturbed during late-summer blooms.
"One of the things that makes it so magical up there is that the bioluminescence is stirred up by motion, whether it's a mullet or the waving motion of a paddle or the wake of a boat," said Edie Widder, a co-founder and senior scientist at the Ocean Research & Conservation Association in Fort Pierce.
"It's a magical light show," Widder said.
One of Florida's foremost authorities on the peculiar phenomenon, Widder has observed bioluminescence from submersibles in the western Mediterranean Sea and bays in Puerto Rico. But perhaps her brightest eyewitness viewing occurred near Haulover Canal on Merritt Island a few years ago.
Does this unusual glowing water — which was noted by Spanish explorers centuries ago — serve as a health indicator of the imperiled Indian River Lagoon ecosystem? Perhaps.
Robust bioluminescence could signal that inorganic nitrogen levels are rebounding after theywere consumed by a devastating "superbloom" of green algae in 2011, said Troy Rice, director of the Indian River Lagoon National Estuary Program.
Extending from Eau Gallie northward to Scottsmoor, the toxic superbloom sickened water quality across about 130,000 acres of the estuary. All told, roughly 47,000 acres of seagrass perished — and then, dense brown-tide algae bloomed the past two summers.
"That superbloom just impacted everything. It was in huge, huge densities that blotted out the sunlight for everything else. The water just turned kind of a chocolate-brown color," Widder said.
That said, Widder welcomes glowing reports — pun intended — of photosynthesis-powered bioluminescence in the Banana River. She said recent sampling data detected up to 750,000 light-producing organisms per liter of water, indicating that sunlight is streaming through the river.
"I consider the bioluminescent Pyrodinium bahamense being back as a good sign. There are some people that might not agree with me about that," Widder said.
Last year, Durocher only offered one nighttime bioluminescence kayak tour because the phenomenon was so weak. But since June, he's already guided nine tours, including trips off Port Canaveral, Merritt Island's Kelly Park and Cocoa Beach's Thousand Islands.
On the unhealthy side, Pyrodinium bahamense blooms can create a poison called saxitoxin, which accumulates in marine animals — particularly puffer fish. In 2002-03, saxitoxin sickened 28 people in the Titusville area and led to a statewide ban on harvesting puffer fish.
Symptoms include tingling, burning, numbness, drowsiness, incoherent speech, breathing difficulties and death, the Florida Fish and Wildlife Conservation Commission warns.
On Aug. 7, the St. Johns River Water Management District reported a reddish-brown bloom of a variety of Pyrodinium bahamense south of State Road 520 in the Banana River Lagoon. Biologists warned the public that the algae is known to produce saxitoxin.
Earlier this week, Durocher led a group of nine kayakers on a three-hour bioluminescence tour on the Banana River. Launching at sunset from a dirt ramp south of Canaveral Lock, the flotilla paddled to the second spoil island north of the channel.
Clouds glowed orange and red above the horizon, and Venus rose overhead. Redfish dorsal fins poked out of the water as they hunted across the flats, and the Norwegian Gem stood illuminated in the distance at Cruise Terminal 5.
By 8:15 p.m., paddle strokes produced a brief, faint greenish glow. But within an hour, paddle strokes and kayak wake created brilliantly hued swirls, like someone stirring glow-in-the-dark Kool-Aid mix in a pitcher.
"When I moved to Cocoa Beach 31 years ago, I was walking with my wife in the water and our feet started glowing. I called the Coast Guard, because I figured that there must be some sort of toxic waste or something," Durocher recalled.
"The guy on the phone just laughed at me," he said.
Copyright 2013 by ClickOrlando.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.