When I first ventured into the Gulf of Mexico in the 1950s, the sea appeared to be a blue infinity too large, too wild to be harmed by anything that people could do. I explored powder white beaches, dense marshes, mangrove forests, and miles of sea grass meadows alive with pink sea urchins, tiny shrimps, and seahorses half the size of my little finger. I learned to dive in unexplored areas offshore from the many rivers that flow into the Gulf, where jungles of crimson, green, and brown seaweed sprouted from rocky limestone reefs. Under the canopy of golden forests of drifting sargassum, I swam with a floating zoo of small creatures: lacy brown sea slugs, juvenile jacks, and flying fish no larger than dragonflies.
Diving into the cool water of Ichetucknee, Weeki Wachee, Wakulla, and other inland springs, I glimpsed the honeycomb plumbing of underground tunnels, sinkholes, shafts, caves, and disappearing rivers that are common along the Gulf, all shaped from rock formed from the bodies of ancient sea creatures with calcium carbonate shells, skeletons, or cell walls. Bones of extinct mammals are there too—creatures that lived long before the arrival of humans. Ice ages have come and gone, with sea level high enough at times to drown most of the Yucatán and Florida, alternating with long stretches when both had more than double the dry land present today—changes that took place over millions of years.
Then, in mere decades, not millennia, the blue wilderness of my childhood disappeared: biologic change in the space of a lifetime.