Biscayne Bay in Spanish Bahia Vizcaina, is 428 square miles and is divided into three parts:
- North Bay between the Miami Beach barrier island.
- Central Bay the largest part of the bay is separated by the Atlantic ocean and the Safety Valve (a series of shallow sand flats separated by tidal flow channels).
- South Bay is separated from the Straits of Florida by the northernmost of the Florida Keys, including Card Sound and Barnes Sound.
Due to bulkheading, dredging, raw sewage spills and urban runoff, the water quality of both North Bay and Central Bay have been severely affected over the last century. Further, with the creation of artificial islands, there has been a loss of natural freshwater flow into the bays. In 1979 regular monitoring of the bays began and there has been a steady improvement over the water quality since then. South Bay, on the other hand, has been less affected, but it too suffers from the loss of natural fresh water.
Designated a state aquatic preserve in 1975, that spans the entirety of Biscayne Bay from the Oleta River in the north to Card Sound in the south. Central Bay is excluded from this designation and is known as Biscayne National Park established In 1980. Shortly thereafter, a second preserve was added off the Cape of Florida on Key Biscayne, and now known as the Cape Florida to Monroe County Line Preserve. Seven houses of Biscayne Bay’s historic Stiltsville remain and are now within the boundaries of the National Park.
Originally, in 1513 Juan Ponce de León called the bay Chequescha. Then in 1565, Pedro Menéndez de Avilés called it Tequesta. During the British occupation of Florida, they called it Cape River, Dartmouth Sound, and Sandwich gulp. A 17thcentury map shows Cayo de Biscainhos, which is thought to be the probable origin of Key Biscayne. For some time it was known as Key Biscayne Bay, but late in the 19thcentury, it became and remains today, Biscayne Bay.
In 1912, the first bridge was built across the Biscayne Bay. It was 2.5 miles, wooden and known as the Collins Bridge after the builder John S. Collins. His son-in-law Thomas Pancoast assisted him. Financing was provided by Carl G. Fisher and the Lummus brothers, John and James. The costs were originally projected at $75,000 but due to delays, there were cost overruns. When the bridge was finally opened, it was hailed as “The longest wooden vehicle bridge in the world opening up the area as a luxury winter resort and playground.” There was a toll of 20 cents each way, but in 1920 it was changed to 15 cents one and 25 cents round trip. In 1925, it was torn down, and in 1925 the more substantial Venetian Causeway bridge replaced it.
There are four other bridges connecting the barrier islands and the mainland, the MacArthur Causeway, the Julia Tuttle Causeway, the John F. Kennedy, and the Rickenbacker Causeway. Connecting the mainland to the northern part of Key Large is the Card Sound Bridge.
Photo by D Ramey Logan – View of northern Biscayne Bay showing Downtown Miami (2014).