Expedition to Evaluate Dry Tortugas Ecological Reserve

Elkhorn coral and a white-spotted filefish.

Elkhorn coral and a white-spotted filefish.

High resolution (Credit: NOAA)

This summer, NOAA scientists continued a long-running study of Florida’s remote Dry Tortugas Ecological Reserve, widely recognized as home to some of the most productive and unique marine resources in the entire Florida Keys National Marine Sanctuary. The information they gathered will be added to eight years of research on the effects of marine protected areas on the rich marine life and habitats of the Florida Keys. 

Scientists from NOAA’s National Centers for Coastal Ocean Science (NCCOS) conducted the latest expedition to the reserve from July 25 through Aug. 5 aboard the NOAA ship Nancy Foster. For the study, researchers surveyed important ecosystem components like coral reef habitat and reef fish at 30 permanent research stations and approximately 55 newly established research sites throughout the Tortugas reserve, as well as in Dry Tortugas National Park and adjacent unprotected areas.

A reticulated brittle star.

A reticulated brittle star.

High resolution (Credit: NOAA)

The mission, which was sponsored by the NCCOS Center for Coastal Fisheries and Habitat Research, included innovative ship-based acoustic surveys of fish and habitats around several of the research stations. To get a better idea of how fish use different habitat types, the scientists studied fish behavior where the edge of the coral reef meets the sandy seafloor, recording observations both on and off the reef.

These transitions between coral reefs and other habitats are an important part of the research because habitat edges are often particularly sensitive to ecological change. NCCOS studies have also shown that seagrasses, seaweeds and microalgae growing on the seafloor around coral reefs are critical to the health of coral reef communities, indicating a need for greater study of this important habitat type, which covers more than 70 percent of the Tortugas reserve.

A school of blue tang.

A school of blue tang.

High resolution (Credit: NOAA)

The data collected on these expeditions help provide marine managers with the tools and information needed to make informed stewardship decisions about protected areas like the Tortugas reserve. This research also addresses fundamental questions about the value of protecting habitats adjacent to coral reefs that are the source of energy for the reef fish community.

One important consideration in the design of marine reserves is the minimum size necessary for them to be effective. Since many species of fish move between different habitat types throughout their life cycles, a reserve that is below a certain size may only protect a species at certain stages in its life. On the other hand, if the reserve is large enough that species are likely to spend their entire lives within its boundaries, it encourages the growth of self-sustaining populations that can “spill over” and increase the numbers of fish outside the reserve.

A spotted cleaner shrimp on pink-tipped anemones.

A spotted cleaner shrimp on pink-tipped anemones.

High resolution (Credit: NOAA)

The Dry Tortugas, a remote area about 70 miles to the west of Key West, Fla., is known for its extensive coral reefs, fish, sharks, lobsters and other marine life. The 800-square-nautical-mile Tortugas reserve was designated in July 2001 to protect important fish habitat and reduce fishing effort in critical areas. This protection offers an ideal opportunity to study the benefits of marine reserves to fisheries species and habitat health, and provides environmental, social and economic benefits.

NOAA’s Office of National Marine Sanctuaries and NCCOS have a long-running partnership to apply NOAA research capabilities throughout the National Marine Sanctuary System, providing sanctuary managers with the best available science and informing effective management of sanctuary resources. Click here to see the daily mission log. NOAA logo.