Environment & Energy
Related: About this forumRobots find Barrier Reef coral at extreme depths, amazing ocean scientists
http://www.guardian.co.uk/environment/2013/jan/06/coral-deep-sea-robotsA diver exploring the coral reef surface. Photograph: Vladimir Levantovsky / Alamy
Robots have found living coral on the Great Barrier Reef at a depth four times greater than most scuba divers can reach and far beyond the depth at which scientists expected to find them.
A team from the Catlin Seaview Survey discovered the reef corals living at 125 metres, the deepest ever found on the reef. Reef corals are in a perilous state around the world, under threat from climate change through warming oceans and acidification of seawater as well as by coastal pollution and unsustainable fishing practices. The remarkable find was made on the outer edge of the Ribbon Reefs off the north of the Barrier. The extreme depth is more than four times the depth of the shallow reef coral habitat (0-30m) which most scuba divers can reach.
Dr Pim Bongaerts from the Global Change Institute at Queensland University, who led the expedition's deep reef team, said: "It's intriguing. When we began our survey, we were amazed to see significant coral at depths of around 60 metres. However, it is truly mind-blowing to see reef coral at more than twice that depth.
"We found the plating Leptoseris corals at a depth of 125 metres. Although the corals are small and at such depth only consists of few species, it shows that there are viable communities living down there. The corals were attached to the rock surface and were certainly not individual corals which have fallen down to this depth. The discovery shows that there are coral communities on the reef existing at considerably greater depths than we could ever have imagined."
MuseRider
(34,125 posts)moving for many many years deeper and deeper because of the change in temperature and because of the difficulty on that side of the reef to study we have just missed the move? If so and the world survives and eventually cools future generations of who or whatever survives may live to see them again in the shallower depths Evolving to survive or just undiscovered because of the difficulty of the site? Whatever, I am thrilled to see this. Having spent a lot of time on beautiful coral reef and watching the amazing things that happen in them I am content to know that they survive even if I will never probably be able to see them again (hard to get to the reef now). This really makes me happy.
Scootaloo
(25,699 posts)Shallow-water corals rely in large part on photosynthesis from algae living in their polyps. When the water warms to a certain degree, the polyps expel the algae, and end up starving to death. problem is, these species of coral will suffer the same problem in deeper water, as less light filters down - they still end up starving.
What you're seeing here is an unexpected discovery of deepwater corals, that don't rely as much (or at all) on photosynthesis, and not a "migration" of shallow-water corals to deeper waters.
Do also note that corals are not the only reef-builders out there, or potential reef-builders. Glass sponges, mollusks, red algaes, lampshells, cyanobacteria, all can form reefs, and have in the past (corals are pretty new on the ocean scene, appearing in the Jurassic or so). Obviously all of those have fallen from the top spot in the modern day, barring a handful of exceptions. Corals will probably fall back as well. Who knows, in five million years, maybe the seas will be colored by the feathery legs and gigantic penises of reef-forming barnacles
MuseRider
(34,125 posts)I would like to see a photo of that barnacle.
It will be different if it survives most likely but I wish I could see it.
Scootaloo
(25,699 posts)That thing can be up to five inches long... Which is amazing when you realize that the barnacle itself is probably smaller than one of your fingernails.
MuseRider
(34,125 posts)I have seen some barnacles under lights on night dives, never saw that though. They are pretty, just not as pretty as a coral reef. Makes me sad that we are losing that beauty on this planet. Other things will come of it and if Mother Nature succeeds in tossing us off who knows how beautiful it may become? Thanks, lol.
LawnKorn
(1,137 posts)20 thousand years ago, sea level was 120 meters lower than it is now.
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