Virginia Beach bioluminescence: What's lighting up the water?
If you want to night surf in glowing blue waves or dance on sand that 鈥渓ights up鈥� with聽聽on Virginia Beach, Va., you might want to hurry.
Friday聽night surfers and hundreds of beach goers flocked to the Sandbridge section of Virginia Beach to revel in what experts say is likely the result of a healthy algae bloom.
Wildlife biologist聽聽says that 鈥淕enerally it鈥檚 completely without hazard to you as a swimmer or surfer. How long it will last is all over the map because bear in mind, you鈥檙e talking about living organisms.鈥�
鈥淭hese living organisms are living in the currents and tides of the ocean,鈥� Mr. Galante adds, 鈥淪o if you get a strong wind event or a large current event they can be gone in a couple of minutes. But if you don鈥檛 get one of those events and there鈥檚 a ton of these things it can stick around weeks.鈥�
鈥淚 used to time certain surf trips so that I was surfing in bioluminescence at night,鈥� Galante says.
Alison Phillips who works at聽聽on Sandbridge Beach, was among those who experienced the awe of an oceanfront Friday night that looked more like something out of the movie聽聽than a typical night surfing.
鈥淚t was totally rad,鈥� MS. Phillips says in an interview. 鈥淲e didn鈥檛 surf or disturb the water because we didn鈥檛 know what was causing it and if we might hurt it. But it was amazing. I鈥檝e lived here all my life, 22 years and I鈥檝e never, ever seen anything like this before.鈥�
Galante explains that swimming and surfing in this bio bloom won鈥檛 harm the creatures causing it.
鈥淚t鈥檚 a chemical reaction that鈥檚 released by oxygen,鈥� he explains. 鈥淭he organisms emit a light-emitting pigment. Basically that reacts with oxygen. So when you react with the waves and bring excess oxygen into the water you glow. When the waves break and oxygen is getting mixed in the water is dark but the wave breaks, the foam, is emitting the light.鈥�
Is this a sign of a healthy ocean?
According to Galante, bioluminescence occurs widely in聽鈥�巑arine聽鈥獀ertebrates聽and聽鈥�巌nvertebrates, including some bioluminescent聽鈥�巄acteria. This kind of phenomenon, he says, can be caused by of cold, nutrient-rich waters from the ocean floor, or by stagnant water in bays, or by water pollution.
鈥淚t can go either way as to being healthy or unhealthy,鈥� Galante says. 鈥淚f there鈥檚 an algal bloom that鈥檚 happening because of a major upwelling event where deep water currents are coming up to the surface in the ocean that鈥檚 great. That means it鈥檚 healthy and lots of good things are coming to the surface.鈥�
Conversely, 鈥淚f it鈥檚 in a bay where the waters are really stagnant, like when you leave a pot of water out in the sun too long and there are no nutrients you get one kind of dominant algae (like a ) and that algae is light emitting, it can be a sign of a negative effect.鈥�
Since no red tides have been reported in the area, Galante says this is likely an outbreak of dinoflagellates, perhaps,聽, a plankton that's known to generate bioluminescence when agitated. These single-celled creatures measure about 1/500th of an inch and release tiny bursts of light that shine hundreds of times bigger than themselves.
Michelle Coley, at the聽Virginia Aquarium and Marine Science Center, agrees: "This聽is bioluminescence created by creatures called dinoflagellates that聽will present this sort of phenomenon during the late summer and early聽fall when water temperatures are warm and the sea is calm. This 'light show' happens due to their increased numbers."
According to the Smithsonian website, each聽聽bursts into light when it feels pressure against its cell wall. The light is given off in an instantaneous process; when you add the light bursts of 750,000 dinoflagellates per cubic foot of water together the effect is spectacular!
Galante explains that, 鈥淎lmost all marine bioluminescence is (greenish) blue in color because the blue-green light [wavelength around 470 nanometers] transmits furthest in water. Most organisms are sensitive only to blue light, although the luminescence in this case is readily visible to the dark-adapted human eye.鈥�
Also, he adds that the intensity of luminescence of these photosynthetic creatures depends on the intensity of sunlight the previous day. The brighter the sunlight the brighter the waters will glow that night.
Galante concludes, 鈥淚t makes it a really fun time to be in the water.鈥�
