Coral reefs found growing in cold, deep ocean

Nov 04, 2008

Imagine descending in a submarine to the ice-cold, ink-black depths of the ocean, 800 metres under the surface of the Atlantic. Here the tops of the hills are covered in large coral reefs. NIOZ-researcher Furu Mienis studied the formation of these unknown cold-water relatives of the better-known tropical corals.

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

Food highways down to the deep

Cold-water corals are mainly found on the tops of carbonate mounds in areas where the current is high due to strong internal waves. These waves are caused by tidal currents and lead to an increase in local turbulence that results in the seawater being strongly mixed in a vertical direction. The outcome is the creation of a kind of highway between the nutrient-rich, sunlit zone at the sea surface and the deep, dark strata where the 380 metre-high tops of the mounds are found. This allows the cold-water corals to feed on algae and zooplankton that live in the upper layers of the sea. Lophelia pertusa and Madrepora oculata are the most important coral species found on the European continental slopes.

Carbonate mounds

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 analysed 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. However, that may well be the case in the Gulf of Mexico. 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.

Threats

Climate change has exerted a considerable influence on the growth of corals and the development of carbonate mounds. For example, corals stopped growing during ice ages. Present-day global warming and the resulting acidification of the oceans also pose a threat: organisms are less effective at taking up carbonate from seawater that is too acidic. This is true not only for corals but also for some species of algae that are a source of food for the corals. Other activities on the seabed that can cause damage to the coral reefs are offshore industries and bottom trawlers. A number of European areas containing cold-water coral reefs have thankfully already obtained protected status.

Source: Netherlands Organization for Scientific Research

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User comments : 11

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GrayMouser
3.4 / 5 (10) Nov 04, 2008
Did they have to bring up climate change?
drel
3.5 / 5 (8) Nov 04, 2008
it's in their nature
mikiwud
3.3 / 5 (7) Nov 04, 2008
drel,
no,its probably in their contract for their grants!
la7dfa
1.8 / 5 (5) Nov 05, 2008
Stupid is as stupid does. Lets just put a lid on USA and let them pollute their own skies...
Velanarris
2.3 / 5 (6) Nov 05, 2008
Stupid is as stupid does. Lets just put a lid on USA and let them pollute their own skies...


Yes lets. Seeing as the US is the only country to decrease their overall emissions I'm sure the residents of the US will greatly approve of preventing Mexican, European, Asian, and even Canadian emissions from darkening our spacious skies and poisoning our amber waves of grain.
deepsand
1 / 5 (4) Nov 06, 2008
Seeing as the US is the only country to decrease their overall emissions ...

Only by exporting our smokestack industries.
... I'm sure the residents of the US will greatly approve of preventing Mexican, European, Asian, and even Canadian emissions from darkening our spacious skies and poisoning our amber waves of grain.

How would they feel if said industries were repatriated, with the commensurate est. 30% increase in pollutants?

How easy it is to throw ones trash onto a neighbor's property, and then lament the fact that your neighbors aren't living up to your standards.
Velanarris
3.7 / 5 (3) Nov 07, 2008
Seeing as the US is the only country to decrease their overall emissions ...

Only by exporting our smokestack industries.
... I'm sure the residents of the US will greatly approve of preventing Mexican, European, Asian, and even Canadian emissions from darkening our spacious skies and poisoning our amber waves of grain.

How would they feel if said industries were repatriated, with the commensurate est. 30% increase in pollutants?

How easy it is to throw ones trash onto a neighbor's property, and then lament the fact that your neighbors aren't living up to your standards.



Those industries would have to conform. They left due to pollution control laws. If they were forced to repatriate our emissions wouldn't change, their bottom line would.

The trash euphemism is more akin to me giving my neighbor a shredder and him using it to have a confetti party.
bmcghie
2.3 / 5 (3) Nov 08, 2008
Velnarris, you honestly expect American consumers would pay the surcharges incurred by buying domestic? To say nothing of the increase in costs that would result by mandating that industries meet certain emissions standards. I'd LOVE to see Walmart prices then... and the resulting howls from the American populace.
Velanarris
3.7 / 5 (3) Nov 08, 2008
Velnarris, you honestly expect American consumers would pay the surcharges incurred by buying domestic? To say nothing of the increase in costs that would result by mandating that industries meet certain emissions standards. I'd LOVE to see Walmart prices then... and the resulting howls from the American populace.


No I don't, but if it was the only option then they wouldn't be making a choice in the matter. Industry expatriated itself and became a greater polluter.

Don't blame Americans for it, last I checked everyone buys from American companies.
rubberman
1.3 / 5 (3) Nov 09, 2008
American companies who's primary mfg. facilities are in china, korea, india and mexico....other than the mint of course.
MikeB
5 / 5 (2) Nov 09, 2008
Who really exported jobs? Every tax and spend politician, that's who. The myriad taxes in our system end up at the consumer's door. Everything is more and more expensive, while wages have plateaued. Don't blame the American people, blame a bloated government. And if you think it is bad now, just wait until carbon taxes are added in.
Maybe I was wrong, maybe the American people should be blamed for voting the clowns in.
I am not a political animal, but I am an observer.
There is only one voice of sanity in congress, Ron Paul.