Sediment cores tell us that the Thousand Islands were formed when a storm-driven sea broke through the barrier island, leaving behind a deposit known as a flood tide delta. Additionally, from the 1960s to the early 1970s the islands were significantly reshaped by efforts to control mosquitoes as the population of Brevard swelled during the race to the moon.
Sometime in the past three thousand years or so, a storm battered the coast of Brevard, as many have before and since. Winds lashed at the vegetation, and waves pounded the beach. Somewhere along the dune there was probably a weakened section in the protective vegetation. Indigenous people lived in this area and may have cleared some of the palmetto and scrubby oaks, or there might have been a topographical low in the dune that made it susceptible to the sea.
Waves sliced at the beach until water punched through, uprooting palmettos at first and then the entire barrier island was cleaved in two as the heaving sea poured through the opening into the lagoon, pushing sand into shoals rather like those of a river delta. The storm waves receded and the shoals became land. Plants slowly colonized the shoals, and the shifting of sand by Longshore currents gradually closed the inlet.
After many centuries people came to Brevard in droves and soon learned why this area was originally part of Mosquito County. Knowing that the saltmarsh mosquito won't lay its eggs in standing water, biologists learned to control them by "source reduction.” To achieve this goal, large sections of the islands were either ditched or diked to remove the moist sand that the mosquitoes required to lay eggs on. Together with chemical controls it yields a qualified success.
Today these islands are no longer pristine by any means. Large areas of wetland have been converted to upland, supporting a suite of plants not normally associated with each other. But the Thousand Islands still function as habitat, provide a "learning laboratory" for students eager to explore the mazes of mosquito canals, and give us a place to escape the rigors of life. These islands remind us that the power of the ocean to shape the land must not be ignored. They are worthy of our appreciation, our respect, and our continued efforts to preserve them.
Background on the Indian River Lagoon Here and a brief history of Cocoa Beach Here.