Thousands of starfish have been stranded on the beaches of South Padre Island after what investigators are calling a "perfect storm" for starfish.

It's thought that high winds and strong currents coincided exactly to wash up the creatures that had been close to shore feeding.

It's only the third time a case like this has ever been reported, the last being in 2009.

At first it was thought they were victims of the polar vortex, which swept the country during January but then investigators realised it was something else.

"These were healthy starfish," said Tony Reisinger, Cameron County Extension Agent for Coastal & Marine Resources with Texas Sea Grant at Texas A&M University. "Some of them were still alive when they were washed onto the sand.  Once they are out of the water though, they pretty much die."

Reisinger credits Dr. David Hicks, chairman of the Department of Biological Sciences at the University of Texas at Brownsville, for figuring out what really caused it. "Now we have to check back for the weather and sea conditions the last time this happened and see if it matches up."

Grey sea stars are plentiful in the Gulf of Mexico and can also be found all along the coast of the Americas, from Virginia to Brazil. 

"I wondered if this was nature's way of controlling the population," said Reisinger. "I knew we had them but I didn't realise there were so many out there," he said.