National Oceanic and Atmospheric Administration (NOAA) and U.S. Geological Survey (USGS) scientists recently returned from a 21-day research mission with some of the most expansive seafloor documentation ever recorded of the Monterey Bay (MBNMS), Cordell Bank (CBNMS) and Gulf of the Farallones (GFNMS) national marine sanctuaries. The platform for the cruise was the 224-ft. NOAA ship McArthur II.

This was a collaborative venture involving the MBNMS; CBNMS; GFNMS; USGS; National Marine Fisheries Service (NMFS), Santa Cruz Laboratory; Northwest Fisheries Science Center, Newport, OR; Washington State University Vancouver, Vancouver, WA; NOAA Marine Protected Areas Center's Science Institute (MPA); and Deep Ocean Engineering (DOE).

Researchers mapped the seafloor with side-scan sonar and captured video showing the diversity of sea life, health of habitat and characteristics of the seafloor, including a first look at many areas. The cruise consisted of 3 different legs: Cordell Bank Survey (1-7 April); Fanny Shoal and Shelf Survey in GFNMS (7-14 April); and Continental Shelf Survey in the MBNMS (14-22 April).

Results of the research from the 2004 McArthur II seafloor mapping cruise of the sanctuaries will provide valuable characterization of sanctuary biology and geology that is useful as a foundation for management of the national marine sanctuaries.

Mapping, describing and visualizing seafloor habitats and their biodiversity within the sanctuaries will help managers to protect important habitats, plants, and animals. The knowledge of what is present today will also provide the foundation to monitor changes in these important resources.

Goal of mission:
To acoustically image, document and film extensive seafloor habitats and life on the seafloor within the MBNMS, CBNMS, and GFNMS as part of a multi-agency seafloor mapping project.

Technology and equipment used:
The small (60 kg) video-sled (1.3 m long x 0.4 m wide x 0.5 m high) was towed underwater behind the NOAA research vessel McArthur II to film and document habitats and life on the seafloor of the MBNMS, CBNMS and GFNMS. Scientists used a Klein 3000 side-scan sonar system to acoustically image several previously unmapped sections of the seafloor within these sanctuaries. During the cruise (April 1 to April 21) teams of scientists worked day and night to collect information on the seafloor using towed video and side-scan sonar. Seafloor descriptions were recorded by the scientists every 30 seconds during real-time observations of the seafloor, providing a wealth of information about habitats and life on the seafloor.