WATER CIRCULATION and CURRENTS

Florida Bay Circulation and Exchange Study

Florida Bay Project Profile - 104

---

Question: How do Florida Bay waters interact and exchange with the Gulf of Mexico and the Atlantic Ocean? What is the water quality of these waters? Is Florida Bay water going to the reef?

Experiment: Every other month a cruise track on the RV Calanus goes from Miami, around the Dry Tortugas, up to Naples and then down through western Florida Bay to Long Key. Water samples are measured for temperature, salinity, chlorophyll and nutrients. Drifter buoys are deployed in the Shark River plume and are then tracked via satellite. Additionally, a catamaran is used to sample currents and water properties in the shallow interior basins throughout Florida Bay.

Permanent temperature and salinity probes have been mounted within the Shark River plume, the western boundary of Florida Bay and along the Florida Keys reef tract. Flow meters have also been installed on the southwest Florida shelf, west Florida Bay and on the Atlantic side of the Keys.

Findings To Date: Shark River drifters traveled into western Florida Bay and then moved either through Long Key Channel toward the Florida Keys National Marine Sanctuary or southwest to the Dry Tortugas. Associated low-salinity water was also traced to the Florida Keys reef tract. Approximate travel time was one to two months depending upon wind speed and direction.

Winds, from the southeast in the summer and from the north to northwest in the winter, create cross key pressure gradients that drive Florida Bay water toward the reef tract at a flow rate of 500-700 cubic meters per second (m3/s; that’s 100 times greater than peak fresh water discharge out of Shark River). East and northeast winds in the fall cause subtidal flows from the Atlantic Ocean toward Florida Bay at a flow rate of 200 m3/s.

Status: This is a two year project which began September 1997.

Restoration Impacts: Understanding the transport of waters into and out of Florida Bay is critical to south Florida ecosystem restoration activities, especially computer modeling efforts.

Funding Source: NOAA - Coastal Ocean Program.

Other Related Profiles:

• FBPP-100 • FBPP-102

• FBPP-103 • FBPP-107