Boat strike is cause of death of right whale female found off Virginia. What to know.

In yet another setback for North Atlantic right whales, a female that recently gave birth was found dead about 50 miles off the coast of Virginia at the end of March, according to NOAA Fisheries. The cause of death was a boat strike, the agency announced Thursday afternoon.

It's the fourth confirmed death of a right whale along the East Coast this year. The tally doesn't take into account three newborn calves that have not been seen with their mothers, including the newly dead whale's baby.

A Cape Cod contingency — a four-person team from the International Fund for Animal Welfare led by animal rescue veterinarian Sarah Sharp — assisted with the necropsy.

"The vessel’s impact caused catastrophic injuries to the whale’s back, fracturing its spine, and leading to a death that was likely agonizing but relatively quick," Sharp said in an email.

NOAA Fisheries noted the whale's spine was dislocated and fractures were found in all vertebrae in the lower back, injuries "consistent with blunt force trauma from a vessel strike prior to death."

Researchers in Massachusetts, which annually sees one of the highest densities of right whales in Cape Cod Bay of anywhere along the East Coast as the animals migrate north for summer, are discouraged by the latest loss.

“The situation so far in 2024 for right whales highlights the fact that much more needs to be done to prevent the extinction of this species,” said Amy Knowlton, a senior scientist with the Anderson Cabot Center for Ocean Life at the New England Aquarium. “It is frustrating that solutions that could address these threats are not being implemented more immediately.”

Knowlton was among the team who helped identify the newly deceased whale, listed as #1950 in the North Atlantic right whale catalog that's maintained by aquarium researchers. The whale was at least 35 years old and had only recently given birth to her sixth known calf. The pair was last seen, both in good health, on Feb. 16 off Amelia Island in northern Florida, according to the aquarium.

The calf has not been seen since the mother was found, and aquarium researchers say the baby, if alive, is not expected to survive without its mother. Right whale calves typically nurse for about a year.

Where was the whale carcass found?

NOAA Fisheries on Tuesday reported that the mother whale's carcass was found on March 30 by a team from HDR, Inc. that was undertaking mid-Atlantic whale surveys for the U.S. Navy. The shark-scavenged remains were found in the ocean east of Virginia's Back Bay National Wildlife Refuge and were towed ashore for a necropsy to determine the cause of death.

The leading causes of death for right whales are vessel strikes and entanglement in traditional fishing gear. This latest death follows three others since the start of the year.

What other deaths have occurred?

On March 3, two months after fishermen spotted it offshore from Edisto, South Carolina, with its head, mouth and lips cut open by a boat propeller, a calf was reported dead on Cumberland Island National Seashore in Georgia, according to NOAA. The baby was the firstborn of the current calving season, initially spotted with its mother, Juno— listed as No. 1612 in the North Atlantic Right Whale Catalog — on Nov. 28. It was Juno's eighth known calf since 1986.

A female yearling was found dead offshore of Savannah, Georgia, on Feb. 13, the first known offspring of Pilgrim (#4340) — a local favorite thought to have been born in 2013 in the warm waters of Cape Cod Bay near the Pilgrim Nuclear Power Station.

A 3-year-old female (#5120) washed up dead on Martha's Vineyard on Jan. 28. That individual suffered a chronic entanglement with traditional fishing rope consistent with rope used in Maine state waters for trap/pot buoy lines, according to NOAA Fisheries.

Unusual Mortality Event designation

The agency said the latest death is the 40th in the ongoing Unusual Mortality Event impacting North Atlantic right whales, which began tallying deaths and injuries in 2017. Since then, the effort has counted 34 seriously injured, and 51 otherwise sick or injured whales.

Survival of this species depends on no more than one whale death per year, according to NOAA Fisheries. For the critically endangered species, every loss takes them closer to extinction, but female deaths are especially devastating because there are so few reproductively mature females left.

The latest population study released last fall placed the number of remaining right whales at 356, plus or minus seven, though the recent deaths and disappearances put the number around 349. The Center for Coastal Studies retiring director of right whale ecology, Stormy Mayo, has said only about 70 of the remaining whales are females old enough to reproduce.

Philip Hamilton, senior scientist with the aquarium’s Anderson Cabot Center, said if a female can avoid "the double threats of vessel strikes and entanglements," she may produce 10 or more calves during her lifetime.

"With the loss of Catalog #1950, her female lineage now rests with her three daughters, none of which have calved yet,” he said.

The population in recent years has also seen lower birth rates, and births at longer intervals.

Slowing ships down: Ships speeding off Cape Cod now get texts to slow down, protect right whales

Changing speed regulations

As part of an effort to protect right whales, NOAA is proposing modifications to existing vessel speed regulations, including expanding the size and timing of seasonal speed zones along the East Coast. The proposed changes also call for including most vessels between 35 and 65 feet in the restricted speed zones, and calling for mandatory adherence to speed limits within so-called dynamic speed zones in areas where right whales are seen and likely to linger.

The proposed changes, now under interagency regulatory review, include both an expansion in time and space of seasonal speed zones; extending restrictions to include most vessels measuring 35 feet to 65 feet in length; and implementation of mandatory, instead of voluntary, speed restrictions in dynamic speed zones, which are established when​ and where​ right whales are observed and are likely to remain.

The proposed changes were first released 18 months ago. Scientists and conservationists are upset about the delay.

“As we watch this species go extinct one by one, the solution sits idle in the hands of the (Biden) Administration," said Kathleen Collins, IFAW senior marine campaign manager. "The science is clear, reducing vessel speeds saves whales. The amended right whale vessel speed rule needs to be finalized, enacted, and enforced before we lose this critically endangered species.”

Sharp agrees.

"The choice is simple: vessels either slow down or the North Atlantic right whale goes extinct," she said. "How many more right whales are going to be sacrificed before something changes?”

NOAA Fisheries noted in its announcement about the cause of death that additional histological and diagnostic testing of samples from #1950 is pending. NOAA’s Office of Law Enforcement is investigating the incident.

Heather McCarron writes about climate change, environment, energy, science and the natural world. Reach her at hmccarron@capecodonline.com, or follow her on X @HMcCarron_CCT

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This article originally appeared on Cape Cod Times: North Atlantic right whale found dead off Virginia, the fourth in 2024