By Margaret Dolan and Børge HolteThe study area in Troms III, offshore North Troms (north Norway). The two new coral occurrences are marked in the lower right portion of the map, around 20 km from the coast of Vannøya.
On Wednesday night as we ran a video transect at around 260 m depth over what seemed to be quite a featureless sand and muddy seabed (with the odd patch of boulders and cobbles) our video screens were suddenly filled with corals – most prominently the reef forming coral Lophelia, and the sea fan Paragorgia. The first video images came during a normal planned video transect as we passed over a small mound, and we next investigated a slightly larger mound around 5 m high of 20 -30 m diameter. The corals on the second mound turned out to be even more abundant with a wealth of associated fauna, including redfish also inhabiting the mound. As the pictures show the coral colonies are massive, even though the reef dimensions are limited.Pictures from video filming of coral colonies found offshore Vannøy. The corals are massive, even though the two reefs filmed are only a couple of tens of metres in diameter.
Analysis of the data material gathered from Troms III will begin this year at The Geological Survey of Norway and The Institute of Marine Research, against a background of detailed bathymetry data from surveys coordinated by the Norwegian Hydrographic Service. Besides geological and biological analyses the data will also be put together to describe the various habitats in the area. All the results will lead to better scientific knowledge of the offshore area which in turn can be used for sustainable management.
In very broad terms we have seen that the shallow banks near the coast have generally quite hard bottoms with sand, cobbles and pebbles common. These areas are also quite exposed in terms of currents. The marine life here has a different mode of living and ways of finding food than in the deeper areas to the west and north, where the seabed is much more muddy.An unusually dense occurrence of brittlestars, each around 5-7 cm big, which was observed at 230 m depth on Fugløybanken. The brittlestars are lying with their legs in the ‘air’ and catching food particles from the passing currents.
MAREANO will be back at sea again in a few weeks with the autumn cruise starting on 17th September and running until 12th October. This cruise will finish mapping in Troms III, north-east of the area covered in the summer cruise. The cruise will also move further south to deep waters in Nordland VI (offshore northwest Norway, not far from The Lofoten Islands). Further work in Nordland VI will continue in 2011.