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The prospect of snorkeling in the mangroves is not often greeted with enthusiasm. Mangroves are easily thought of as hot, buggy, smelly swamps. This assessment is essentially correct for mangrove basin forests found in the Virgin Islands. These occur where mountain guts flow into large flatlands bordered by shallow well-protected bays. Mangrove basin forests can be hot and muggy, with little breeze and lots of insects. Moreover, the abundance of decaying organic matter in the swamp sends off a decidedly disagreeable odor. Snorkeling the basin forest mangroves is not particularly inviting. Another mangrove habitat, called a fringe forest, can also be found in the Virgin Islands. In a fringe forest, mangroves grow along a narrow, partially submerged shelf situated between a well-protected bay and sharply rising hillsides. Because the mangroves in a fringe forest are confined to a narrow shelf of land, there are no extensive wetlands and less organic debris, hence the fringe forest is far less humid, supports less insect life and is not as foul smelling as the basin forest. Here, snorkelers can comfortably observe the utterly fantastic underwater world of the mangroves. You can snorkel right up to the mangroves and, taking care not to kick up sediment, look inside the tangle of roots. You will be astounded by this vast nursery for tiny fish, such as miniature, blue tang, French grunts, yellowtail snapper, butterfly fish, jacks, damselfish, sergeant majors, parrotfish, old wife, fry and barracuda. The dense, shallow environment of the mangrove roots offers an exceptionally wide variety of baby fish safety from the appetites of larger fish as well as a thick soup of nutrients provided by the decay of mangrove leaves and twigs. The more you look, the more you'll see - small colorful corals and sponges encrusted to the mangrove roots, oysters, baby lobsters, shrimp, crabs, sea cucumbers, sea urchins and conchs. You may find it amusing to observe the tiny barracudas, some just an inch or two long, exhibiting the same fierce behavior as their larger counterparts, lying almost motionless in the water waiting for the opportunity to dart out and devour fish even tinier than themselves. The long white strands of what look like thread or thin spaghetti belong to a class of tubeworms aptly named spaghetti worms. Gently touch the strand and it withdraws slowly back into its tube. Another strange creature that inhabits the underwater mangrove environment is the upside-down jellyfish. These creatures are in the same family as corals and exhibit many of the same traits. The upside-down jellyfish supplements its diet of whatever it can trap within its tentacles with food produced through photosynthesis by single-celled algae that have a symbiotic relationship with the jellyfish. As compensation for sharing their food, the algae are allowed to live, secure from danger, inside the poisonous tentacles of the jellyfish. The upside-down jellyfish spends most of its life lying upside-down on the bottom of mangrove lagoons, allowing the algae can get sunlight. The scientific name of the upside-down jellyfish is Cassiopeia frondosa. Virginia Barlow in her excellent book, The Nature Of The Islands, gives this explanation of the origin of the name: "Cassiopeia was a mythical queen who was turned into a constellation by a group of gods who favored her. She was then positioned in the sky by another group of gods who were her bitter rivals. These gods placed her so far north that she appeared upside-down for much of the year, a punishment for her vanity." Also commonly seen on fringe forest mangrove snorkels are an abundance of algae with descriptive names such as Neptune's shaving brush, white scroll algae, mermaid's fan, and the sea pearl, an iridescent alga, which is one of the largest one-celled organisms in the world. They can be as big as a ping pong ball. The best places to snorkel the fringe forest mangroves on St. John are Princess Bay, Otter Creek and Water Creek. Of these, only Princess Bay has convenient land access; it's located right off the side of Route 10 (the East End Road), 1.8 miles east of the Coral Bay Moravian Church. Remember to respect the fragility of this most important environmental resource and enjoy! For a wonderful descroption of the Mangrove environment replete with illustrations and easy to read descriptions see Virginia Barlow's Nature of the Islands. |
