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TitleQuaternary geological features and oceanographic conditions supporting coral and sponge gardens in the northern Labrador Sea and Baffin Bay
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LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorEdinger, E; Neves, B; Wareham, V E; Campbell, D CORCID logo; Davin, S; Sherwood, O; Dinn, C; Dufour, S; Hillaire-Marcel, C; Archambault, P
SourceProgram and abstracts: 2017 GeoHab Conference, Dartmouth, Nova Scotia, Canada; by Todd, B JORCID logo; Brown, C J; Lacharité, M; Gazzola, V; McCormack, E; Geological Survey of Canada, Open File 8295, 2017 p. 48, Open Access logo Open Access
LinksGeoHab 2017
PublisherNatural Resources Canada
Meeting2017 GeoHab: Marine Geological and Biological Habitat Mapping; Dartmouth, NS; CA; May 1-4, 2017
Documentopen file
Mediaon-line; digital
RelatedThis publication is contained in Program and abstracts: 2017 GeoHab Conference, Dartmouth, Nova Scotia, Canada
File formatpdf
ProvinceNorthern offshore region; Newfoundland and Labrador; Nunavut
NTS3; 13; 14; 15; 16; 19; 27; 28; 29; 37; 38; 39
AreaLabrador Sea; Baffin Bay
Lat/Long WENS -80.0000 -44.0000 78.0000 52.0000
Subjectsmarine geology; surficial geology/geomorphology; environmental geology; geophysics; mapping techniques; oceanography; marine environments; coastal studies; conservation; marine organisms; marine ecology; resource management; biological communities; marine sediments; glacial deposits; continental margins; continental slope; geophysical surveys; acoustic surveys, marine; sonar surveys; seismic surveys, marine; bathymetry; bedrock topography; debris flows; gas seeps; methane; benthos; Corals; Sponges; Biology; Phanerozoic; Cenozoic; Quaternary
ProgramOffshore Geoscience
Released2017 09 26
AbstractDeep-sea corals and sponges are a diverse group of habitat-structuring organisms found at continental slope depths in most of the world's ocean basins. Their distributions are influenced by oceanographic parameters such as temperature and salinity at coarse scales, and by surficial and bedrock geology and intermediate and fine scales. Recent remotely operated vehicle (ROV) video surveys focusing on twelve cold-water coral and sponge habitat sites in the northern Labrador Sea and Baffin Bay, Canada, were accompanied by acquisition of multibeam sonar and sub-bottom profiles, enabling analysis of the geological features upon which the coral and sponge habitats have grown. CTD casts in the same locations gathered data on temperature, salinity, seawater density, nutrient concentrations, and calcium carbonate saturation state.
Most of the Northern Labrador Sea coral and sponge habitats are developed on glacially deposited materials. On the NE Saglek Bank, the site with the highest abundance of large gorgonian corals in the region, a diverse coral fauna occurs on current-swept bouldery gravels of glacial or glaciofluvial origin, with channels resembling glacial outwash fan channels between 300 and 400 m water depth. Further north in the Labrador Sea, near the Hatton Basin, SE Baffin shelf and slope, and Cape Dyer sites, diverse sponge-rich habitats appear to be most common on ice-contact bouldery gravels that have been extensively scoured by icebergs. On the outer side of the Hatton Basin sill, Primnoa resedaeformis-rich coral faunas are well developed on bouldery gravels that are interpreted as the grounding-line facies. CTD profiles at some of these northern Labrador Sea locations suggest sharp thermoclines associated with water mass boundaries, which likely also influence the distribution of the corals.
Dense Keratoisis sp. bamboo corals in SE Baffin Bay are developed on muddy bottoms overlying a trough-mouth fan in SE Baffin Bay. Although the bamboo corals baffle sediments, creating small-scale topography, the ridges observed in multibeam and sub-bottom profile are glaciomarine in origin, likely till-tongues or glacigenic debris flows.
Multibeam sonar and sub-bottom profiles were used to examine the geology of two sites with reported possible cold-seep related mounds, on the NE Saglek Bank and the SE Hatton Basin. Both sites are found within the iceberg-scoured ice-contact sediment facies. No evidence of authigenic carbonates or cold-seep related mounds was observed in multibeam sonar, sub-bottom profile, or box-core. Multibeam and sub-bottom profiles of the reported possible mound field in SE Hatton Basin revealed an iceberg-scoured ice-contact bouldery gravel facies, consistent with that observed at the NE Hatton basin sponge-dominated site. Methane bubbles and microbial mats were confirmed at a known hydrocarbon seep from Scott Inlet, in NW Baffin Bay. Bedrock exposures along cliffs in Scott Inlet support abundant Cladorhiza carnivorous sponges.
Diverse sponge gardens were found on rill-and-gully morphology glaciomarine gravelly sands in SW Baffin Bay. The species composition of these sponge gardens appears to be quite different from that found in the northern Labrador Sea and in Frobisher Bay. Both the coral and sponge gardens contribute to benthic biodiversity throughout the region.
Summary(Plain Language Summary, not published)
The sixteenth annual GeoHab Conference was held this year (2017) at the Waterfront Campus of the Nova Scotia Community College in Dartmouth, Nova Scotia, Canada.

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