"If you've ever boated on the lagoon, you've seen them — dozens of small, sandy, mangrove-covered islands scattered across the water. They look natural, like they've always been there. But they haven't. Most of them are less than 70 years old. They're called spoil islands, and they're a story of how humans accidentally created new habitat."
What Are Spoil Islands?
Spoil islands are small, human-made islands created by dredging. When a channel is deepened, the material scooped from the bottom — sand, mud, shell, rock — has to go somewhere. Instead of hauling it away, it's dumped alongside the channel, where it piles up above the waterline. Over time, vegetation takes hold: first grasses and shrubs, then mangroves. Birds nest on the islands. Crabs and fish shelter in the roots. What started as a pile of mud becomes a living island. The Indian River Lagoon has over 130 spoil islands, most of them created during a single massive dredging project in the 1950s and 1960s.
