Sand Island
Less than 50 years ago Sand Island actually was an island. The natural forces of wave action and storm surge have removed the sand, leaving a very shallow carpet of coral rubble in the back reef. Amid several small spurs and scattered coral patches are two major coral fingers, neither as high as those on neighboring Molasses or French Reefs.
The depth at the middle of the three mooring buoys at Sand Island is about 14ft. Swimming seaward, you may discover a large bowl-like depression about 22ft deep, formed by the two main ridges. Hawksbill turtles and nurse sharks often rest on the sand here, and it’s always a good place to stop for a while and let the reef “equalize” around you. Most of us spend far too much time moving quickly about the reef, and as a consequence, most of the fish we see are swimming away from us. Stop for even five minutes in the Florida Keys, and they’ll come back to check you out. Stay in one place for 10 minutes and you’ll be just another part of their world.
From the sand bowl the reef bottom slopes gently down to about 30ft. Scattered sea plumes and sea rods dominate this section of the reef, along with the occasional flattened head of star or brain coral. As at French Reef to the north, parrotfish are abundant at Sand Island. On this rather plain part of the site you’ll likely encounter roving bands of blue parrotfish, munching their way along the reef. They’re actually scraping the live polyps and algae from the coral, but they ingest pieces of the reef at the same time. The coral fragments are ground to fine sand in their gullets and excreted back onto the reef. An active parrotfish can churn out more than 2lbs of sand a day. Groups of six or seven, like the blue parrotfish patrols at Sand Island, can make up to a ton of sand each year.
Reproduced with permission from Diving & Snorkeling Florida Keys 2001 Lonely Plant Publications www.lonelyplanet.com