What causes — and doesn’t cause — marine mammal strandings along NC's coast
Marine mammal experts on North Carolina’s coast want to combat misinformation about the cause of strandings. It comes after two sperm whales stranded and died along the state’s coast in December: one at Cape Lookout and one at Nags Head.
The causes of those whale deaths are still being investigated. Both whales were very emaciated, said Vicky Thayer, the N.C. Division of Marine Fisheries’ marine mammal stranding coordinator.
Even with recent occurrences, however, Thayer said North Carolina's yearly marine mammal strandings are actually somewhat decreasing. Still, the state has a high average of 92 stranded marine mammals a year. About 10-12% of those are whales, Thayer said.
Craig Harms, director of the marine health program at North Carolina State University’s Center for Marine Sciences and Technology, said that, unlike in some other places, marine mammal strandings in North Carolina are unlikely to have a happy ending.
“The popular conception among the public that if you just push them back into water, they'll be fine, is something that we struggle with a little bit,” Harms said. “Usually these animals, they're seriously sick or injured before they hit the beach. They didn't hit the beach because it was just an accident. They were there because they're in really rough shape.”
Marine mammals can become stranded on the state's coast due to boat collisions, infectious diseases, or gear entanglement, Harms said. Balloons can cause them too, as was the case in the November death of a beaked whale at Emerald Isle. Harms and Thayer had conducted a necropsy on the whale.
“When we opened this stomach up, the digestive tract, we found that that Mylar balloon was blocking passage of any foods to the rest of the stomach,” Thayer said. “It was a young female whale who was nursing, so there was milk in her stomach.”
Notably, Thayer said offshore wind energy development isn't causing the state's strandings. Not only does North Carolina have very little wind energy development activity, as pointed out by Harms, but the National Oceanic and Atmospheric Administration also maintains that there is no evidence linking offshore wind energy development to whale mortalities.
Thayer said that she has heard the unsubstantiated claim more frequently.
“As scientists, we're just interested in the facts,” Thayer said. “We can't — and don't want to — jump to conclusions. The facts are that there has not been any evidence that the exploration for potential sites for wind energy have caused the death of any whales.”
Politicians, former President Donald Trump, have recently touted such claims.
Last week, NOAA released a strategy to promote protections for endangered right whales and the responsible development of offshore wind energy.
Stranded marine mammals along central N.C.’s coast can be reported by calling the Marine Mammal Stranding Network’s 24-hour hotline at (252) 241-5119.