Beaches have become makeshift necropsy labs along the shores of New York and New Jersey. An alarming number of whales are washing up along the east coast of the US. And when they do, a team of researchers arrives at the scene to hunt for clues pointing to a cause of death.

They start by examining the outside of the body. Are there teeth marks from an attack? Or are there telltale signs of an accident with a ship: gashes from propellers, rust that has rubbed off from the vessel, broken bones or flesh that’s been pushed in from the impact?

“I can certainly tell you from my experience, I’ve seen a lot of ship-struck whales,” says Joy Reidenberg, who’s typically on call for such investigations.

The victims have become posthumous poster children for opponents of offshore wind energy — despite a lack of any evidence that wind farms are to blame. That distracts from very real risks shipping vessels pose to whales navigating US shorelines, experts say.

More than 30 dead whales have washed ashore on the east coast since December 31st, many of them in New Jersey and New York. It can be incredibly difficult to figure out a cause of death — a grim task scientists often volunteer to help out with on their own time. And while they’re not always able to find the answers they’re looking for, what they see time and again is evidence of run-ins with ships.

“The data seems to be pointing overwhelmingly to ship strikes,” says Reidenberg, a comparative anatomist at the Icahn School of Medicine whose research focuses on marine mammals.

Reidenberg volunteers for New York’s Atlantic Marine Conservation Society and New Jersey’s Marine Mammal Stranding Center, organizations authorized to respond to stranded whales.