Here the bioluminescent organisms will concentrate because they can't get out of the bay. They're
too small and not fast enough swimmers to find their way upstream snaking through the channel to return to the open ocean.
Nor would they want to, because the conditions in the Bio Bay's mangrove lagoon are just right for them.
The entire bay is encircled by mangroves whose leaves are constantly falling into the water. These rotting
leaves provide a perfect diet for the dinoflagellates.
Moreover, the salinity of the water is perfectly suitable to the dinoflagellates. It is kept within their
narrow tolerance levels because of the presence of lagunas or salt ponds just behind the mangrove lagoon that collect water
during periods of high tides and during intense rains and filter the fresh water back slowly afterward.
Another important factor is that there is no significant quebrada or fresh water stream leading into the bio
bay that could lower the salinity to undesirable levels. Human contamination from sewage, a factor which has seriously degraded
a bioluminescent bay on the Big Island, which was once a rival to Mosquito Bay, is not a problem in Vieques, and hopefully
never will be.
Tests have shown that the Bioluminescent Bay in Vieques contains as many as 720,000 bioluminescent organisms
per gallon of water. This concentration is so great that if you splash the water you will cause them to emit enough light
so that you could read the print on a book in the dead of night.
Dinoflagellates are non-toxic and you can get in the Bio Bay and swim around with them, and your whole body
will be encircled by an unbelievable aura of light. If you splash water on your hair it will drip crystals of light like tiny
sparkling jewels. If it starts to rain, the whole bay will light up.
Truly an amazing experience!"
From the book "Vieques" by Gerald Singer