Federal scientists are using sonar to map deep water canyons about 100 miles off the coasts of Virginia and Maryland.

Among other things, they're looking to identify shipwrecks, sensitive biological habitats and coral communities.

Technicians aboard the National Oceanic and Atmospheric Administration ship Nancy Foster will use sonar to generate 3-D seafloor maps.

Those maps will help guide sampling activities during future expeditions when they will use a remotely operated vehicle to survey habitat and make collections.

This is the first cruise of a four-year project to study the biology, geology and oceanography of canyons off the middle Atlantic coast of the United States.

The Nancy Foster left Charleston, South Carolina for the expedition Saturday. It is scheduled to return June 17.

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