The bay is unusual because it was not formed by sea level rise at a river's mouth. It is a depression between two different types of limestone.
Miami Beach, Virginia Key, Key Biscayne and Key Largo are underlain by coral reef limestone formed by marine life.
Only a small area east of Key Biscayne is all that remains of Biscayne Bay-Cape Florida to Monroe County Line Aquatic Preserve. The rest has become part of Biscayne National Park where it remains under protection.
The mainland is composed of oolitic limestone, formed by the physical and chemical conditions within shallow water.
The bay supports Johnson's seagrass, a threatened species under federal law (the first marine plant to be listed), found only in southeast Florida.
Submerged habitats also include hardbottom areas of algae and sponges, soft sediments of sand or mud, and seagrasses.
Florida manatees inhabit the bay and are more often observed in the winter time when they gather in warm water areas during cold fronts.
August 13, 2021 - 11:13am
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The Florida Department of Environmental Protection is the state’s lead agency for environmental management and stewardship – protecting our air, water and land. The vision of the Florida Department of Environmental Protection is to create strong community partnerships, safeguard Florida’s natural resources and enhance its ecosystems.