Coral reefs found growing at a depth of thousand meters in the Atlantic Ocean

Amsterdam, Nov 5 : A team of researchers has found coral reefs growing at depths of six hundred to a thousand meters in the Atlantic Ocean.

Furu Mienis, a researcher from the Royal Netherlands Institute for Sea Research (NIOZ), led the research team.

Mienis studied the development of carbonate mounds dominated by cold-water corals in the Atlantic Ocean at depths of six hundred to a thousand meters.

These reefs can be found along the eastern continental slope from Morocco to Norway, on the Mid-Atlantic Ridge and on the western continental slope along the east coast of Canada and the United States.

Mienis studied the area to the west of Ireland along the edges of the Rockall Trough.

In her research, Mienis analyzed environmental factors like temperature, current speed and flow direction of seawater as these determine the growth of cold-water corals and the carbonate mounds.

The measurements were made using bottom landers, observatories placed on the seabed from the NIOZ oceanographic research vessel 'Pelagia' and brought back to the surface a year later.

How the carbonate mounds were formed was investigated by using a piston core from the research vessel to take samples of up 4.5 metres of sediment.

These cores were then cut into thin slices that were analyzed separately; the deeper the layer, the older the sediment.

The samples studied were aged up to 200,000 years old.

Large hiatuses found in the core were possibly caused by major changes in tidal currents. The groups of carbonate mounds develop in the direction of the strongest current and their tops are of equal height.

The mounds were found to be built up from carbonate debris and sediment particles caught in between coral branches.

These cold-water coral reefs have, therefore, not developed as a result of leakage of natural gas from the sea bed.

This area is currently being studied from the American research vessel 'Nancy Foster' by Furu Mienis, her supervisor Tjeerd van Weering and NIOZ associate researcher Gerard Duineveld.

ANI