Local anglers appreciate Florida reefs if for no other reason than that it is where the fishing is good. Millions of vacationers value the reefs not only for the fishing, but for the snorkeling and SCUBA that the reefs afford. But they are so much more.
What exactly defines a reef? They not only have 3D relief but characteristic gaps between their building materials. The gaps provide shelter for many different animals. It is for this reason that abiotic or non-living processes such as the accumulation of sediments that form a sandbar can function as a reef, the variability of spaces between the sand grains; why a sunken ship can be a reef because of the diversity of living spaces it provides; and, why rocks piled up beneath the surface by ancient glacial or seismic action can provide reef services. But it can take many years for the growth of living organisms on the surface of the abiotic reef to approach the productivity of the living reef.
Biotic or living reefs not only provide shelter but simultaneously provide food and even more importantly are continuously growing. Florida’s most famous living reefs form the quintessential Florida Reef Tract, the only one of its kind in the United States. The Tract covers over 350 miles stretching from Martin County on the east coast south to the Dry Tortugas. It is the fourth largest barrier reef in the world and as with all coral reefs is constantly changing. As new colonies grow up to more than six inches a year, other parts of it are disintegrating by natural processes and predation, a dynamic and rich environment that provides for most of Florida’s commercial and sport fish at some point in their lives.
But the shallow corals that form the Florida Reef Tract are not the only ones in Florida’s living reef system. Slightly less diverse and somewhat discontinuous, coral reefs continue northward up the west coast of Florida to the Florida Middle Grounds. Located in the bight of the panhandle, the middle grounds are two parallel submerged ridges with numerous pinnacles that are home to abundant stony coral species distinctly different from those of the Florida Tract. Nearly 300 species of invertebrates and 170 fish species contribute to the rich marine life of the region.
On the east coast of Florida, an entirely different animal, sabellariid worms, are the primary live bottom reef builders. Extending 200 miles from the north end of the Florida Reef Tract in Martin County to St. Augustine, the worms and their colonial tube masses contribute to not only the food web but significantly to the protection and evolution of the shoreline in that region. Dr. David Kirtley, associated with Florida Oceanographic up until his death in 1997, literally wrote the book on these worms that are studied by zoologists, oceanographers, geologists and ocean engineers because of their importance in the high energy region of our shorelines.
Twenty miles off Florida’s east coast and nearly paralleling the track of the sabellariid inshore reefs are the deepwater oculina or ivory tree coral reefs. Discovered in the early 1970s by John Reed with a submersible from the then Harbor Branch Institute they are found in water up to 300 feet below the surface. We now understand the tremendous importance of these reefs for commercial species and as a rare and endangered habitat. They are found no where else in the continental United States.
Finally, a discussion of the biotic reef types in Florida would not be complete without recognition of the oyster reef, one of the most endangered marine habitats. Oysters, like the other living reefs, are considered a keystone species, without which there would be none of the associated animals. Oysters are unlike the other reefs in that they need brackish water to thrive and as filter feeders contribute significantly to the maintenance of water quality. But they are vulnerable to wide swings in salinity, so like our other precious resources they need vigilance and monitoring. Coincidently oysters are the focus of Florida Oceanographic’s current director of scientific research, Dr. Vincent Encomio who has dedicated his career to the restoration of the once great beds that covered the region.
Living reefs are the backbone of our economic well-being in Florida. They are prized for recreation, priceless for healthy fisheries, valuable for our water quality and essential for our quality of life. It is the wide extent and diversity of our living reefs that set Florida apart as the reef capital of the United States.