Where sharks go to die: Researchers find unique 'underwater graveyard' of giant fish



Carcasses of large animals could provide about four percent of the total food on seabed

First time animals other than whales have been observed being scavenged



A deep-sea graveyard discovered by chance off the coast of Angola has revealed where some of the the largest animals in the sea go to die.

Researchers were stunned to find the carcasses of four large marine creatures - a whale shark and three rays - laying at the bottom of the ocean floor.

Each was surrounded by around 50 scavengers in a food frenzy, giving new insights into how large sea creatures are 'recycled' when they die.

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Researchers were stunned to find the carcasses of four large marine creatures - a whale shark and three rays - lay at the bottom of the ocean floor. Still images showi each of the observed carcasses. A Whale shark (Rhincodon typus); B Mobulid carcass 1; C Mobulid carcass 2; D Mobulid Carcass 3.

WHALE FALL A whale fall is the carcass of a cetacean that has fallen onto the ocean floor. As they are found at depths of 2,000 m or 6,600 ft, they create complex localized ecosystems that supply sustenance to deep-sea organisms for decades. Organisms that have been observed at deep-sea whale falls include giant isopods, squat lobsters, bristleworms, prawns, shrimp, lobsters, hagfish, Osedax, crabs, sea cucumbers, and sleeper sharks.

Experts say the finding may help scientists reveal the fate of dead ocean giants, according to findings published in the journal PLOS ONE.

'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,' lead author Dr. Nick Higgs, from the University of Plymouth's Marine Institute, said, according to BBC News.



Researchers say that carcasses of large animals could provide about four percent of the total food that arrives on the sea floor in this area.

'The carcasses of large pelagic vertebrates that sink to the seafloor represent a bounty of food to the deep-sea benthos, but natural food-falls have been rarely observed,' the team wrote.

'Here were report on the first observations of three large ‘fish-falls’ on the deep-sea floor: a whale shark (Rhincodon typus) and three mobulid rays (genus Mobula).



The find included the corpse of a whale shark (pictured) which was being feasted on by 50 animals, while eels lay in wait to eat those coming to feast

'These observations come from industrial remotely operated vehicle video surveys of the seafloor on the Angola continental margin.'

The dead bodies 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.

Higgs said '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,' he said.

'These carcasses can support scavenger communities on the deep seafloor for weeks to months at a time, but unlike larger marine mammal carcasses, they do not appear to host characteristic 'whale-fall' fauna and are primarily significance for mobile scavengers,' the researchers wrote.

























