Mystery Sea Monster? Nope, Just a Dead, Stinky Whale

Monster of the deep? Or just a really funky dead whale?

A monstrously huge creature that washed ashore on a remote Indonesian beach, oozing a mysterious red fluid, is probably a baleen whale in an advanced state of decomposition, experts said.

The nearly 50-foot-long (15 meters) marine creature was lying on Hulung Beach on Seram Island, Indonesia, and was first discovered by 37-year-old local resident Asrul Tuanakota, who initially mistook the creature for a boat, the Jakarta Globe reported.

Despite the blob's bizarre appearance, it's clearly a baleen whale, said Alexander Werth, a whale biologist at Hampden-Sydney College in Virginia.

"There is lots of stuff in the ocean that we don't know about — but there's nothing that big" that remains unknown, Werth said.

Two dead giveaways revealed that the creature was a whale, Werth said: the grooves, or "throat pleats," and the upper jaw where the two racks of baleen plates, used for filtering out food in the whale's mouth, would have been.

While scientists can say for sure that the whale belongs to the genus Balaenoptera, it's not clear exactly which species it is: It could be either a blue whale or a Bryde's whale, Werth said. However, Bryde's whales are not usually that big. The creature could also be a fin whale, said Moe Flannery, the collections manager in ornithology and mammalogy at the California Academy of Sciences. (The creature is definitely not a humpback, she added.)

Mysterious cause of death

While it's tough to determine a cause of death in an animal in such an advanced state of decomposition, some clues can still be gleaned from the carcass, Flannery said. For instance, if the a ship struck the whale, signs of trauma such as fractured ribs would still be apparent. Identifying a bacterial infection would be difficult this far after decomposition. However, if the animal died of domoic acid toxicity, sometimes caused by algal blooms, a urine sample could reveal that, Flannery added.

At the least, researchers always try to take a tissue sample, which contains DNA that would reveal the species of whale and the gender, she said.

As for the reddish tinge in the water surrounding the whale, that is probably a combination of blood and grease, Flannery said.

"Whales are full of oil, and it's kind of orangey," Flannery told Live Science.

Originally published on Live Science.