GEOSCAN, résultats de la recherche


TitreDistribution and morphology of Horse Mussel Beds in the Bay of Fundy identified using Multibeam Sonar
AuteurKostylev, V E; Parrott, D R; Dickson, R; Todd, B J
SourceNGF Abstracts and proceedings of the Geological Society of Norway no. 2, 2009 p. 49
Séries alt.Secteur des sciences de la Terre, Contribution externe 20120025
Réunion8th International Conference, GeoHab - marine geological and biological habitat mapping; Trondheim; NO; mai 5-7, 2009
ProvinceRégion extracotière de l'est
Lat/Long OENS-67.5000 -64.5000 45.5000 44.2500
Sujetspeuplements biologiques; levés sismiques; levés de reflexion sismiques; topographie du fond océanique; topographie du fond océanique; bathymétrie; glaciation; topographie glaciaire; dépôts glaciaires; écosystèmes; géologie des dépôts meubles/géomorphologie; géologie marine
Résumé(disponible en anglais seulement)
The presence of horse mussel (Modiolus modiolus) reefs in the Bay of Fundy has been known for the last decade since their discovery using sidescan sonar and high resolution seismic systems. The reefs are long, thin, and parallel structures covered with epifauna. Since 2006, the Geological Survey of Canada, in cooperation with the Canadian Hydrographic Service and the University of New Brunswick, acquired 12,465 square kilometres of multibeam sonar coverage in the bay. We have identified and outlined mussel beds by visually inspecting the multibeam bathymetry and backscatter strength maps. Horse mussel beds are expressed as elongated and elevated ridges with backscatter strength different from the surrounding seabed. Approximately 1500 mussel beds were mapped and measured. The beds are located in 40 - 100 m water depths with a median depth of 76 m. The beds ranged in length from 32 m to 2 km with median length of 185 m and were on average several meters high. The shape of the beds was more irregular and less linear in areas of multidirectional tidal current. The total area of the horse mussel beds in the bay is approximately 11,670,283 square meters. Seismic reflection data show that the reefs are associated with glacial till in shallow subsurface. Distribution maps and morphological data could be used to design and implement protection measures for this important ecosystem component of the Bay of Fundy.