Offshore wind farms misleadingly blamed for whale deaths

A spate of whale strandings along the Mid-Atlantic coast of the United States has inspired claims on social media that offshore wind farms are to blame. This is misleading; scientists and environmental groups say there is no evidence linking the facilities to the deaths, and that other important factors include ocean warming, habitat changes and vessel encounters.

"Did you know that Democrat Green policies seem to be killing beloved Dolphins & Whales with dangerous offshore wind turbine construction," says a February 23, 2023 tweet.

The post is part of a series of claims that gained traction on social media in early 2023 after a string of whale strandings in several US states, including New York and New Jersey.

"Could the wind farm high powered sonar blasting be rendering them defenseless to avoid ships?" says a February 16, 2023 Facebook post. "Hard to believe it’s a coincidence at this point."

Screenshot of a tweet taken March 9, 2023

Screenshot of a Facebook post taken March 9, 2023



Between December 2022 and early March 2023, there were 25 large whale strandings along the Mid-Atlantic coast -- most of them humpback whales, according to the National Oceanic and Atmospheric Administration (NOAA). Local and national newspapers have covered the issue, and several environmental groups and ocean conservation campaigners have voiced concerns.

But claims that surveying for wind farms is behind the deaths are unfounded, experts told AFP.

"At this point, there is no evidence to support speculation that noise resulting from offshore wind site characterization surveys could potentially cause mortality of whales," said Allison Ferreira, a spokeswoman for NOAA's Greater Atlantic Regional Fisheries Office, in a March 6 email.

Vessel strike 'most consistent cause of death'

Ferreira said NOAA has been monitoring unusual humpback whale deaths since 2016 -- "with elevated strandings along the entire East Coast."

"There are currently 186 humpback whales included in the Unusual Mortality Event," she said. "Partial or full necropsy examinations were conducted on approximately half of the whales. Of the whales examined, about 40 percent had evidence of human interaction, either ship strike or entanglement."

This screenshot of a NOAA graphic taken March 9, 2023 shows the number of humpback whales strandings per year since 2012 ( NOAA)

This screenshot of a NOAA graphic taken March 9, 2023 shows annual North Atlantic Right Whale deaths and their causes ( NOAA)



Frances Gulland, chair of the US Marine Mammal Commission, said in a March 3 email that "in the cases where cause of death could be determined, vessel strike is the most consistent cause of death."

Regina Asmutis‑Silvia, executive director of Whale and Dolphin Conservation (WDC) North America, told AFP on March 9 that humpback and North Atlantic right whales -- an endangered species with a population of less than 350 -- are under the most scrutiny.

"Anything that happens to a right whale poses a concern and is another step toward extinction," she said.

In February 2023, for example, a right whale washed up in Virginia Beach. Multiple agencies performed a necropsy and found the whale "suffered a catastrophic blunt force traumatic injury," according to WDC, with injuries "consistent with vessel strike."

In addition to such collisions, Asmutis‑Silvia cited warming oceans and habitat changes as reasons for the recent influx in whale strandings.

"It's a combination of a changing climate, where waters are warming, and the particular fish that they're feeding on: Menhaden," she said.

There has been a resurgence of the Mid-Atlantic fish over the past several years, thanks in part to harvest limits set in 2012. That has in turn attracted other species, such as striped bass and tuna.

Whales have also followed the food -- including to busy shipping areas.

"Habitat distribution and the consistency with which you can see whales is definitely changing," Asmutis‑Silvia said. "Unfortunately, they're hanging out in places where there is lots of vessel activity and particularly, obviously, the port of New York is a very high-risk area."

Noise pollution

Underwater noise can disorient whales, several studies have found. But such disturbances can come from many sources -- including military testing, oil and gas exploration, and ocean vessels.

In 2008, the US Navy acknowledged in court that its military sonars could cause "behavioral disruptions" and short-term hearing loss in dolphins and whales. Scientists had previously accused the Navy of downplaying such noises, some of which the 1972 Marine Mammal Protection Act considers "harassment."

Noise affects marine animals and travels differently depending on factors such as water temperature. Asmutis-Silvia said it is "not easy to evaluate the impact of noise on animals that are decomposed."

That is particularly true for whales.

"They are covered in blubber," she said. "They literally heat up and the tissues break down almost immediately."

Graphic looking at how pilot whales use echolocation to navigate underwater, and listing various theories about what could go wrong to lead to strandings ( AFP Graphics)

Douglas Gillespie, a senior research fellow at the University of St Andrews in Scotland, told AFP in a March 5 email that it is "certainly true that pile driving during wind farm construction is loud enough that nearby marine mammals could suffer harm."

Such noise, he said, can cause hearing loss in extreme circumstances -- but it is "certainly wrong to associate any whale death with a technology just because it's new."

"Many whales strand on the US coast each year," said Gillespie, whose work focuses on monitoring the effects of offshore renewable energy on marine life. "Some are from unknown causes, many are from causes which we know well: namely fishing gear entanglement and ship strikes."

Yanis Souami, an underwater noise expert, agreed the construction of renewable energy structures can produce substantial noise. But "during the operating phase, no significant impact has been noticed," he said in a March 9 email.

The US Bureau of Ocean Energy Management (BOEM) monitors and manages offshore energy activities. Erica Staaterman, a bioacoustics researcher with BOEM's Center for Marine Acoustics, said in a January media teleconference that, compared to oil and gas exploration, wind surveying equipment is relatively small and produces little noise.

"Those in oil and gas are called seismic air guns, and they're specifically designed to penetrate kilometers into the sea floor," she said.

AFP has fact-checked other environmental claims here.