Exploration of the Canyon-Incised Continental Margin of the Northeastern United States Reveals Dynamic Habitats and Diverse Communities.
The continental margin off the northeastern United States (NEUS) contains numerous, topographically complex features that increase habitat heterogeneity across the region. However, the majority of these rugged features have never been surveyed, particularly using direct observations. During summer 2013, 31 Remotely-Operated Vehicle (ROV) dives were conducted from 494 to 3271 m depth across a variety of seafloor features to document communities and to infer geological processes that produced such features. The ROV surveyed six broad-scale habitat features, consisting of shelf-breaching canyons, slope-sourced canyons, inter-canyon areas, open-slope/landslide-scar areas, hydrocarbon seeps, and Mytilus Seamount. Four previously unknown chemosynthetic communities dominated by Bathymodiolus mussels were documented. Seafloor methane hydrate was observed at two seep sites. Multivariate analyses indicated that depth and broad-scale habitat significantly influenced megafaunal coral (58 taxa), demersal fish (69 taxa), and decapod crustacean (34 taxa) assemblages. Species richness of fishes and crustaceans significantly declined with depth, while there was no relationship between coral richness and depth. Turnover in assemblage structure occurred on the middle to lower slope at the approximate boundaries of water masses found previously in the region. Coral species richness was also an important variable explaining variation in fish and crustacean assemblages. Coral diversity may serve as an indicator of habitat suitability and variation in available niche diversity for these taxonomic groups. Our surveys added 24 putative coral species and three fishes to the known regional fauna, including the black coral Telopathes magna, the octocoral Metallogorgia melanotrichos and the fishes Gaidropsarus argentatus, Guttigadus latifrons, and Lepidion guentheri. Marine litter was observed on 81% of the dives, with at least 12 coral colonies entangled in debris. While initial exploration revealed the NEUS region to be both geologically dynamic and biologically diverse, further research into the abiotic conditions and the biotic interactions that influence species abundance and distribution is needed.
Cherokee Nations Technology Solutions, Contracted to the Wetland and Aquatic Research Center, US Geological Survey, Gainesville, FL, United States of America.
Andrea M
AM
Quattrini
NOAA, NMFS, National Systematics Laboratory, National Museum of Natural History, Washington, DC, United States of America.
Martha S
MS
Nizinski
USGS Woods Hole Coastal and Marine Science Center, Woods Hole, MA, United States of America.
Jason D
JD
Chaytor
Wetland and Aquatic Research Center, US Geological Survey, Gainesville, FL, United States of America.
Amanda W J
AW
Demopoulos
Department of Geography, Texas A&M University, College Station, TX, United States of America.
E Brendan
EB
Roark
Department of Biology, University of Louisiana at Lafayette, Lafayette, LA, United States of America.
Scott C
SC
France
Wilkes Honors College, Florida Atlantic University, Jupiter, FL, United States of America; Harbor Branch Oceanographic Institute, FAU, Ft. Pierce, FL, United States of America.
Jon A
JA
Moore
Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States of America.
Taylor
T
Heyl
Department of Marine Sciences and Northeast Undersea Research Technology and Education Center, University of Connecticut, Groton, CT, United States of America; Sea Research Foundation, Mystic Aquarium, Mystic, CT, United States of America.
Peter J
PJ
Auster
NOAA National Ocean Service, Silver Spring, MD, United States of America.
Brian
B
Kinlan
USGS Woods Hole Coastal and Marine Science Center, Woods Hole, MA, United States of America.
Carolyn
C
Ruppel
NOAA Office of Ocean Exploration and Research, Silver Spring, MD, United States of America.
Kelley P
KP
Elliott
NOAA Office of Ocean Exploration and Research, Narragansett, RI, United States of America.
Brian R C
BR
Kennedy
Earth Resources Technology Corporation, Contracted to the NOAA Office of Ocean Exploration and Research, Durham, NH, United States of America.
Elizabeth
E
Lobecker
Department of Geosciences, Mississippi State University, Mississippi State, MS, United States of America.
Adam
A
Skarke
Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States of America.
Timothy M
TM
Shank
D000818:Animals; D037421:Anthozoa; D044822:Biodiversity; D057894:Coral Reefs; D017753:Ecosystem; D009511:New England