View Abstract

Version: 1.2 Status: Approved A new version will be created automatically if this content is modified.
Steve W. Ross, Univ.of NC at Wilmington
Sandra Brooke, Florida State University, US
Stephen Viada, CSA Ocean Sciences Inc., US
Rod Mather, University of Rhode Island, US
Amanda Demopoulos, U.S. Geological Survey, US
Liz Baird, North Carolina Museum of Natural Sciences, US
Andrew Davies, Bangor University, UK
Dolly K. Coykendall, U.S. Geological Survey, US
Gerard Duineveld, Royal Netherlands Institute for Sea Research (NIOZ), the Netherlands
Scott C. France, University of Louisiana, Lafayette, US
A. Howard, Artwork
Christina A. Kellogg, U.S. Geological Survey, US
Furu Mienis, Royal Netherlands Institute for Sea Research (NIOZ), the Netherlands
Cheryl Morrison, U.S. Geological Survey, US
Nancy Prouty, U.S. Geological Survey, US
Michael Rhode, University of North Carolina, Wilmington, US
Brendan Roark, Texas A&M University, US
Craig Robertson, Bangor University, UK
Craig M. Young, Oregon Institute of Marine Biology, University of Oregon, US
A Tale of Two U.S. Atlantic Canyons: Norfolk and Baltimore Canyons
Growing interest (stimulated by energy activities) in ecosystems within and surrounding numerous submarine canyons along the U.S. middle Atlantic shelf and slope led to a 5-year study funded by three U.S. government agencies in collaboration with a variety of national and international partners.  The project, a multidisciplinary study of the oceanography, biology, ecology, geology, and archaeology in and around Baltimore and Norfolk canyons, emphasized communities associated with deep-sea corals, methane seeps, rugged topography, and shipwrecks.  Education and outreach were incorporated throughout the project.  The first cruise (4-17 June 2011) completed multibeam sonar and CTD surveys of the canyons.  A research cruise was conducted in the Baltimore and Norfolk canyon areas between 15 August and 2 October 2012.  During this cruise, two benthic landers and one mooring were deployed in each canyon, and 30 ROV dives (42 to 1,001 m), 76 CTD stations, 62 box cores, and 15 bottom trawls were completed.  The first 2013 cruise (30 April to 27 May) completed 18 ROV dives (90 to 1,612 m), 34 CTDs, 38 box cores, and 17 bottom trawls.  The final cruise (21-27 August 2013) retrieved the benthic landers and moorings, and completed 22 CTD stations.  We will review the overall project with emphasis on key results.

Results and observations during the deeper parts of the field surveys include:

  • Both canyons contained extensive rugged habitats and dense deep-sea coral aggregations.
  • We made the first mid-Atlantic recordings of the corals Lophelia pertusa and Solenosmilia variabilis.

  • Octocorals (mainly Paragorgia arborea) were the most common structure-forming corals.

  • Among octocorals, genetics revealed 11 gorgonian species, 1 soft coral species, and 5 sea pen species, including the first east coast distribution record for one species.

  • Two large methane seeps supported the mussel Bathymodiolus childressi and other diverse fauna.

  • 123 species of fishes were identified from deep canyons (12 new to the region) and 33 species from shelf habitats.

  • Fishes were highly associated with specific habitats in depths above 1400 m; less so > 1400 m

  • Sedimentology, organic deposition, and physical processes differed between the two canyons.

  • Oceanography and geology of the two canyons differed strongly from the adjacent open slopes.

  • Norfolk Canyon is tenfold more enriched in organic carbon than Baltimore Canyon.

  • Baltimore Canyon infaunal communities were less diverse from those on the adjacent slope.

  • Canyon infauna differed from the slope and between the two canyons.

  • Lost fishing gear and trash were frequently observed on the bottom.

  • Results from this project helped support the recommendation to create a very large protected area that includes the mid-Atlantic canyons and deep slope.

Theme 2: New ways to study submarine canyons: integrated programs, new technologies and coordinated monitoring efforts
Oral Presentation
Baltimore Canyon, Norfolk Canyon, multidiscipinary studies, methane seeps, deep-sea corals