Thousands of dead crabs on beaches explained by experts

Posted at 9:39 PM, Jul 10, 2018
and last updated 2018-07-10 22:39:50-04

COASTAL BEND – Carcasses of blue crabs and other marine life have been seen by the thousands along Mustang Island.  At least ten miles of the beach from Access Road 2 to the Port Aransas jetties is covered in dead marine creatures.  The sight of dead blue crabs has aroused concerns in beachgoers wondering if something is affecting the environment.  

"Is it environmental? Is it a natural occurrence, or is it due to pollution? Or is it due to Harvey?" Sandy Atkinson, a beachgoer, said. 

Reports to the Texas Parks and Wildlife of the dead crabs started in early July.  The crab graveyards have been reported at Padre National Seashore, Port Aransas Jetties, and Mustang Island State Park.

Though shocking for someone who has never seen this before, Texas Parks and Wildlife say this has happened before.  The phenomenon is called upwelling.  That is when rain or wind causes deep, cool water to come to the surface.

"What we think happened was a lot of these carcasses went down to the bottom of the ocean, and this upwelling event pushed up a lot of the shell material onto the beaches," Alex Nunez, Regional Response Coordinator for Texas Parks and Wildlife, said.

They believe most crabs died or shed their shells in the water, then got pushed to shore by the upwelling.

Scientists at the  University of Texas Marine Science Institute have a different explanation.  They think that recent heavy rains pushed organic matter into the Gulf, and that created a lack of oxygen in the water, which created something like a dead zone. They think that killed the crabs. 

"I know it’s not normal in the middle of summertime for crabs, dead crabs, thousands of dead crabs to be washing up," beachgoer, Jim Atkinson said. 

None of the experts think this will have a long-term impact on the blue crab population or pose a health risk for humans.