An often-overlooked aspect of Everglades National Park is that about 50% of it is covered with water… but only a few feet. The Ten Thousand Islands is so-called because of the many mangrove islets that dot the tidal flats for over a hundred square miles before giving way to the open Gulf of Mexico. This is an estuary: a place where fresh water from the rivers meets salt water from the ocean. This brackish water that results in estuaries forms the basis for the most productive and diverse ecosystems on earth – and the 10,000 Islands are no exception!
This particular estuary is a result of both a submerged coastal plain (basically a continuation of the very gradual slope of land in south Florida) and the development of shoals from oyster bars. Oysters are one of the unique organisms that not only survive but thrive in brackish water and tidal flats, and it’s only a little exaggeration to say that this area is one huge oyster bed! The pelicans in the photo above are standing on one
such oyster reef. Oysters, and other estuarine species, make up the plentiful bottom of a food chain that feeds local and migratory animals of all sorts – but especially birds and fish! These reefs/bars/shoals also protect the mainland from storm surges and hurricanes, breaking up the force of waves before they hit shore. When these shoals get filled in with a little sediment coming down the rivers, the mangroves are able to get a toehold, and eventually they grow to form the islets, with some higher, drier ground at the center. For the most part, only mangroves grow there, though as debris gets caught in
the mangrove roots, some other plants are able to gain a footing themselves. The outermost islands in the Ten Thousand Islands are true barrier islands, made of sand and shells and supporting a variety of hardy plants that grow above the high-tide line.
Some visitors spend their entire vacation in the Ten Thousand Islands – paddling or boating, fishing, birding, camping. We had other stops to make, and only spent an afternoon here. We took a private boat tour out among the islands and saw an abundance of wildlife, both mangrove and barrier islands, and capped it off with a sunset over the ocean.
Our tour was operated by the Smallwood Store on Chokoloskee Island, which has an interesting history itself. These tours came well-recommended, and I had hoped to get a smattering of local island lore from someone who had spent their lives in the islands, but unfortunately our guide had only been there for a few months and was about to leave for his next job elsewhere. He enjoyed talking about the wildlife and the Islands, but not all
of his ecological facts turned out to be true (I don’t blame him – I think he thought he was giving us accurate information). This was a pattern I noticed while we were down there, that most tour guides (both park staff and private companies) had memorized a little bit of information but couldn’t really extrapolate from that, and sometimes mixed up what they had learned. This is a very heavily-visited area, and most people don’t wonder about the things I’m interested in… but if you do, I suggest reading up before you go, rather than relying on guides or interpreters to inform you!
Final note: last fall I read a novel called Swamplandia! by Karen Russell, which takes place in a fictionalized version of the Ten Thousand Islands and southwest Florida. If you’re looking for something less science-y to read, I highly recommend it.