Thousands of starfish along the North American Pacific Coast are dying a gory death, and scientists don’t know why.

What’s disturbing beyond the mass die-off is how scientists witnessed the creatures actually going: The end result is twisted, dismembered piles of mush that were once toughened starfish. But when scientists began conducting experiments with sick and healthy starfish, they saw the starfish ripping their appendages off.

starfish death

Scientists witnessed starfish appendages “walking” away from the rest of the starfish bodies. (Image source: YouTube)

starfish death

Usually starfish can regenerate such an appendage, but in these cases, they couldn’t. Instead, they spilled out their insides and died. (Image source: YouTube)

Scientists began noticing the deaths last summer, calling it “sea star wasting syndrome” for now, according to Oregon Public Broadcasting’s show Earthfix.

Diver Laura James started documenting the unusual starfish deaths in the ocean off the coast of Washington.

“There were just splats. It looked like somebody had taken a laser gun and just zapped them and they just vaporized,” James told the news station of the starfish she began seeing near her home in Puget Sound.

starfish death

Image source: YouTube

Whatever the cause, it impacts up to a dozen species of starfish up and down the coast. Some reports from the East Coast have come in as well, according to Earthfix.

“The other individuals just started ripping themselves apart,” Ben Miner, a biology professor at the Western Washington University, said of once-healthy starfish studied in the same tank with a sick one. “The arms just crawl away from the particular body.”

It’s after the arms “crawled away” that the guts of the starfish spilled out. Miner said that even healthy starfish placed in tanks without sick individuals still developed symptoms of the mysterious disease at the same rate, showing that an ill starfish isn’t necessarily speeding up the process.

Scientists don’t know if a pathogen or ocean acidification is causing the illness. The scientific world considers getting to the bottom of this mass death important because of the ecological effect it could have. Starfish prey upon various organisms, which if go unchecked could populate out of control.

“These are ecologically important species,” marine epidemiologist Drew Harvell with Cornell University told the news station. “When you lose this many sea stars it will certainly change the seascape.”

Watch Earthfix’s report on the starfish situation:

What’s more, in a seemingly unrelated event, thousands of starfish off the coast of south Texas were beached last week due to rough weather.

“Dr. [David] Hicks is the one who really figured it out,” Tony Reisinger with Texas Sea Grant at Texas A&M University told the Valley Morning Star. “He thinks it was rough seas and high winds and strong currents that made for the right conditions, along with the probability that the starfish were close to shore feeding. All of those forces tossed them up on the shore.”

(H/T: PBS via io9)