This is unexpected and the numbers even more
unexpected. I would like to see these well studied in
order to determine just what happens to the skeleton. Do they also breakdown? I expect so, but this is our chance to find
out.
The reason I ask this is that we do have an ancient rare
seabed fossil that was subjected to the same environment. It would be good to know just how unique
fossilization happens to be.
Not quite an elephants graveyard but it certainly smacks of
just that.
Deep-sea
'graveyard' reveals fate of dead ocean giants
By
Rebecca Morelle
Science
correspondent, BBC News
13 May
2014 Last updated at 06:19 ET
The chance discovery of a
deep-sea "graveyard" is helping scientists to shed light on the fate
of dead ocean giants, scientists report.
Footage recorded by the
oil and gas industry shows the carcasses of four large marine creatures in a
small patch of sea floor off the coast of Angola.
Around the dead whale
shark and three deceased rays, scavengers flocked to the food bonanza.
There were lots of these
fish sitting around the carcasses - they seemed to be guarding it”
Lead author Dr Nick
Higgs, from the University of Plymouth's Marine Institute, said: "There's
been lots of research on whale-falls, but we've never really found any of these
other large marine animals on the sea bed."
Whale carcasses are home
to complex ecosystems, first attracting scavengers such as sharks, then smaller
opportunists such as crabs and shrimp-like creatures called amphipods. Osedax -
or "zombie worms" - feed on the animal's bones, while specialist
bacteria break down fats.
But with this latest
footage, scientists have been able to see how the feeding frenzy that takes
place around other big animal carcasses compares.
The video was recorded by
remotely operated vehicles (ROVs), which were surveying the seafloor around
Angola for industrial exploration.
The dead creatures were
found between 2008 and 2010 on a one-square-kilometre patch of the sea floor
and had been dead for an estimated one or two months.
The researchers mainly
found scavenging fish - up to 50 around each carcass.
"We found three to
four different types - but what really dominated were eel pouts. These normally
sit around the carcass and wait for smaller scavengers - amphipods - to come
along, and they will eat them," said Dr Higgs.
"There were lots of
these fish sitting around the carcasses - they seemed to be guarding it."
But the team did not find
other animals, such as the bone-eating worms, lurking around the dead whale
shark and rays.
"Absence of evidence
isn't evidence of absence... but the ecosystem does seem different to whale
falls," said Dr Higgs.
The team was not sure
why, given how rare sightings like this are, that four dead animals were all
spotted in a small area.
Dr Higgs said:
"There are lots of these animals living in the surface waters, and through
natural mortality, you will have an increased abundance of dead animals on the
seabed. The reason we found them could be because of this industrial survey
work - there are very few places surveyed as intensively as these areas."
The researchers estimated
that the carcasses of large animals could provide about 4% of the total food
that arrives on the sea floor in this area.
"These large carcass
falls can be quite common and support quite a few fish in terms of the amount
of food coming down there - there may be easily enough to support fish
populations."
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