A dozen dead whales have washed up on New York and New Jersey beaches since December. It's part of a years-long trend in whale deaths up and down the east coast. The National Oceanic and Atmospheric Administration is trying to figure out what's going on.

The deaths have led some protesters to call for an end to offshore wind development, saying — without evidence — the sound of the boats and underwater surveying might confuse the whales. Some of those protesters are with the environmental group Clean Ocean Action, but some represent at least one conservative group that opposes offshore wind development.

The Marine Mammal Commission, a federal agency charged with protecting marine mammals, said the deaths are "not new, nor are they unique to the U.S. Atlantic coast."

Sixteen humpback whales alone have stranded along the Atlantic coast this winter. However, the Commission notes "there is no evidence to link these strandings to offshore wind energy development." Many of the deaths are attributed to being hit by ships or getting caught in fishing nets.

NPR host Mary Louise Kelly talks to Jaclyn Jeffrey-Wilensky, a data reporter with member station WNYC, about the whale deaths along the east coast and how they're contributing to misinformation about wind energy.

This interview has been edited for length and clarity.

Tell us more about what's going on.

We've had a number of dead whales washing up on our beaches in the last few months. The most recent one we reported on was just last week in Queens, which had large wounds on its body. NOAA says that's likely from a vessel strike. That's been the case for at least one other whale that washed up recently.

How long has this been happening?

NOAA has been tracking what they call unusual mortality events since 2016. That's the term for when they notice that marine mammals are dying in unexpected ways or significant numbers. Right now on the east coast, they're seeing these events for humpback whales, North Atlantic right whales and minke whales. A lot of these whales die getting struck by ships or tangled up in nets. But it's not 100%.

Over the weekend, there was a rather large protest in New Jersey over the whale deaths. The protesters were calling for a stop to offshore wind development in the area. Is there a connection between whale deaths and offshore wind?

Experts say there isn't.

"At this point, there's no evidence to support speculation that noise generated from wind development surveys could potentially cause mortality of whales," Kim Damon-Randall, director of the NOAA Fisheries Office of Protected Resources, told WNYC.

But some groups — and local politicians — have tried to link the deaths to the wind energy prep work being done in New York and New Jersey waters.

They claim the sound of the boats might confuse the whales, even though the wind surveying is actually less noisy than fossil fuel exploration.

What do we know about the protest groups? Are they environmentalists?

My colleague Nancy Solomon found that some of the people making this claim do belong to an environmental group, but others are just anti-wind power. She discovered that one organization, Protect Our Coast NJ, is connected to a conservative think tank with a long history of opposing clean energy.

If it's likely not offshore wind development, what's driving this spike in whale deaths?

There's no one answer, but experts have some theories. One is that whales may be following prey into waters with more boat traffic, Damon-Randall says.

Damon-Randall says another reason might be climate change. In response to warming oceans, "we are seeing populations move around and go into areas that they haven't historically been in," she says.

There may be more of some whales than there were before. Local humpbacks in particular are no longer considered endangered because of their population growth. More whales can mean more vessel strikes.

What's being done about the vessel strikes and net entanglements that are happening to whales?

NOAA will keep tracking the whale deaths. Large boats are also being instructed to go slow around major ports in the area during winter and spring to reduce the odds of vessel strikes. NOAA is trying to extend those rules to include smaller boats, too.

As for the anti-wind advocates, two Republican congressmen from New Jersey have proposed pausing the offshore wind development and are looking into how it got approved in the first place. But New Jersey Governor Phil Murphy says the work will continue.