A Productive Marine Environment You Can "Bank" On

Fish on shallow reef bank.

When people think of the marine environment of the Florida Keys, most envision the barrier coral reef just a few miles offshore. But coral reefs are just one of several habitat types responsible for the productive fisheries and thriving marine ecosystem that make the Florida Keys famous. New research shows habitats referred to as “bank systems” support a similar abundance and diversity of fishes as do coral reefs, and like coral reefs are sensitive to human and environmental impacts.

Bank systems are clusters of shallow banks and channels located in the nearshore waters between Florida Bay and the Florida Keys. The NOAA report “Biodiversity and Ecosystem Function of Shallow Bank Systems within Florida Keys National Marine Sanctuary” reveals that these bank systems are hot spots of biodiversity, providing essential juvenile nursery habitat, as well as foraging and sheltering grounds for adults of economically important reef fishes. Scientists are also learning about the role bank systems may play in filtering sediments and nutrients from upstream, buffering the offshore coral reef from the full extent of Florida Bay waters.

Bank systems tend to be located near passes between islands and consequently in areas of high boat traffic. Because of the shallow depth of the bank tops, they are frequently damaged by boat groundings and propeller scarring.  Boat groundings destabilize banks by damaging their protective coating of plants and animals, making them vulnerable to erosion by strong tidal currents. As their physical structure erodes, so too does their ecological role.  

Given their critical function in the ecology of the sanctuary and their vulnerability to both man-made and environmental stressors, report authors recommend additional protection to conserve the structure and function of these important habitats.

The Marine Sanctuaries Conservation Series report “Biodiversity and Ecosystem Function of Shallow Bank Systems within Florida Keys National Marine Sanctuary,” authored by John S. Burke, W. Judson Kenworthy, T. Shay Viehman, and Brian Degan of NOAA’s Center for Coastal Fisheries and Habitat Research and Vanessa L. McDonough of Biscayne National Park, is available online at http://sanctuaries.noaa.gov/science/conservation/bank_series.html.