Mapping and imaging deep-sea coral reefs off Norway, 1982–2000

摘要: The survey and mapping group (SMG) of Statoil is responsible for all seafloor pipelines field development in Statoil. During numerous reconnaissance pipeline route surveys over large portions our contintental shelf, the North, Norwegian Barents Seas, we have only detected deep-water coral reefs a few specific areas. first reef found was 1982, using combined side scan sonar sub-bottom profiler system off Fugloy, northern-Norway. Thereafter, were mapped with similar systems mid-Norway, during period 1985–1990 final Haltenpipe project. 1997, also some previously known Trondheimsfjord area while surveying Tjeldbergodden - Skogn Between 1997 2000, more along routes on outer mid-Norway continental shelf. These are smaller size (less than 5 m high) those mentioned above (5–31 high). Although profilers provide less ambiguous detection reefs, that modern multi-beam echosounder data can adequate remotely sensed mapping. interpretation based visual documentation by ROV (remotely operated vehicle) or sampling gravity corers grabs (ground-truthing). Based limited amount such ground-truthing, it has been possible to extrapolate use morphological characteristics map their density distribution. For project, an offshore corridor about 200 km length at width 3 echosounder. On basis ground-truthing 14 suspected total number be 57 within 600 km2 area. All these higher (the highest 31 m) diameters base 50 m. they occur local clusters up 10 per km2, mean entire (200 long) transect 0.09 km2. However, there regional variation, being 1.2 subcropping Palaeocene sedimentary rocks. A brief discussion why corals constructed deep, cool, generally `hostile' waters shelf fjords concludes them probably subsisting reliable steady nutrient source, independent season variations Atlantic Drift (`Gulf stream'). This positive environmental component called `hydraulically active substrata'. It thus speculated micro-organisms, bacteria etc., utilizing hydraulically activated chemical porewater gradients, cause enrichment which cnidarian organisms ultimately depend.