'Mangroves reproduce by dropping their 'propagules' into the water which float across the oceans until they lodge into the ground, on perhaps a distant seashore. There they take root and form a new plant, if allowed to grow. Propagules contain no seeds. They have already matured on the plant and are 'ready to go' plants that only need lodge themselves to send out their roots and leaves. They are viable, floating in the ocean, for up to a year.

The bioluminescent bay in Vieques may be nurtured by the vitamin B12 which is released with the tannins from the red mangrove roots. Nutrition is also created by the decomposition of mangrove leaves etc. This feeds the Pyrodinium bahamense plankton that create such a spectacular sight at night (because of the unusually high density of the light emitting dinoflagellates in this lagoon). There are also many other factors involved in establishing such a density of bioluminescent dinoflagellates).