Twenty Years Mapping the U.S. Caribbean Seafloor Aboard NOAA Ship Nancy Foster

Since 2004, NOAA's National Centers for Coastal Ocean Science (NCCOS) has mapped the seafloor of the U.S. Caribbean, around Puerto Rico and the U.S. Virgin Islands, to fill gaps in what managers know about its varied coral habitats. Local and regional managers chose the priority sites, and local partners helped decide where to map, sample and survey throughout.

Twenty years of work: 23 cruises and a wealth of data. Image from NOAA NCCOS.

Many ways of seeing the seafloor

Over 23 cruises in 20 years, scientists gathered the depth, shape and make-up of the seafloor and information on coral reef ecosystems and fish. Their tools included:

• multibeam sonar, for detailed maps of depth and seabed texture;
• fish acoustic sensors, which detect fish in the water;
• oceanographic instruments;
• lidar, which measures depth with light;
• remotely operated vehicles (ROVs), to see what is really on the bottom.

From these data the team built high-resolution maps that make it far easier to pick out sensitive habitats and explain where fish gather.

NOAA Ship Nancy Foster, run by NOAA’s Office of Marine and Aviation Operations, carried out the missions. Image from NOAA NCCOS.

Aboard the Nancy Foster

All the missions sailed on NOAA Ship Nancy Foster, whose wet and dry laboratories and computers for collecting and analysing data were put to use on every one. The ROVs were lowered from the ship on a cable by a power winch and stayed tethered while the team steered them from on board, collecting sonar depth and backscatter data and the imagery that confirms what the sonar sees.

Lowering an ROV from the ship. Image from NOAA NCCOS.

Piloting the tethered ROV from the ship. Image from NOAA NCCOS.

The team also sent out uncrewed underwater gliders to measure ocean conditions and to listen for the calls fish make around their spawning grounds in the coral ecosystems.

Preparing an underwater glider. Image from NOAA NCCOS.

Putting the data to work

The team built the U.S. Caribbean Acoustic Web Map, which lets local managers see fish density laid over seafloor depth for northeast Puerto Rico, the Southeast Insular Shelf and St. Croix, and find where fish are most abundant. The information helps with overfishing, recreational and commercial fisheries, restoration, pollution from land, permits, marine protected areas, safe navigation, modelling coastal flooding, marine spatial planning and further research. NOAA's Coral Reef Conservation Program supported some of the missions.

Sources

• NOAA National Centers for Coastal Ocean Science, "Twenty Years of U.S. Caribbean Seafloor Mapping Aboard NOAA Ship Nancy Foster"; rewritten in hubnx's own words. Images from NOAA.