Tampa Bay

The District’s SWIM Program also is devoted to restoring the health of Tampa Bay. The Hillsborough River empties into Tampa Bay, which is the largest open-water estuary in Florida. An estuary is a partially enclosed body of water where fresh water from rivers and streams flows into the ocean, mixing with the salty seawater. This mixing of fresh and salt water creates a special habitat — one of the most productive on earth. 

The fresh water that flows into an estuary is essential because it makes the quiet, shallow waters livable for young fish, shrimp, crabs and other animals. Estuaries act as “nurseries” and many of these young animals cannot live in water that is too salty or too polluted. It’s amazing to think that the Hillsborough River, which starts in the Green Swamp 54 miles from Tampa Bay, is so important to Tampa Bay! If the water entering the river is polluted or limited, these young animals and others such as manatees, ospreys and horseshoe crabs could be harmed.

Estuaries also are home to a number of plants including seagrasses. Seagrasses are an important barometer of a bay’s health because they require relatively clean water to flourish, thus they are sensitive to changes in water clarity and quality. District scientists track trends in seagrass to evaluate ongoing water quality improvement efforts. There’s good news! Seagrasses in Tampa Bay are flourishing with the largest amount mapped since the 1950s.