An endangered North Atlantic right whale first spotted in 1989 was found dead off the Virginia coast, the National Oceanic and Atmospheric Administration reported Tuesday, with her most recent offspring missing.

HDR, Inc., a company conducting Mid-Atlantic whale surveys for the Navy, notified the NOAA of the mother's carcass on Saturday about 50 miles off shore, east of Back Bay National Wildlife Refuge in Virginia, NOAA officials announced in a news release.

The administration identified the female whale as #1950 − a mother from this year’s calving season.

"She was first seen in 1989 and gave birth to her sixth calf this winter. Her calf was not seen in the vicinity of the carcass," Lauren Gaches, a NOAA spokesperson told USA TODAY on Wednesday.

Whale carcass towed to shore, necropsy scheduled

After its discovery, the administration's fisheries and partners towed the whale to shore for a necropsy.

"The whale carcass was scavenged by sharks; wind, weather, and distance from shore presented additional logistical challenges for the tow," NOAA reported, adding the agency will provide additional updates as more information becomes available. 

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Death of #1950 marks 40th known mortality of North Atlantic right whales in UME

The siting marked the 40th death in the ongoing Unusual Mortality Event (UME) impacting North Atlantic right whales, according to NOAA.

"Her calf is also considered a seriously injured dependent calf in the UME due to the death of its mother," NOAA wrote in the release.

The UME started in 2017 and, so far, has documented 125 whales, including the mother and her calf: 40 dead, 34 seriously injured, and 51 otherwise sick or injured whales. 

The population of North Atlantic right whales has plummeted 35% over the last 13 years, USA TODAY reported earlier this year.

Nearly wiped out before hunting was banned in 1935, the whales' numbers rebounded in 2011 to 481, but dropped from 2013 through 2020 and stood at an estimated 356, as of February. 

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#1950 last spotted in 2021

The dead whale's age was not known, but according to the The New England Aquarium, #1950 was last spotted by researchers in 2021.

How to report a dead or alive injured or stranded whale:

People who come in contact with the massive creatures are asked to maintain a 1,500-foot distance from the animals.

Whether dead or alive, NOAA asks people to report any sightings of injured or stranded whales.

The Greater Atlantic Marine Mammal Stranding Hotline is (866) 755-6622 and the Southeast Marine Mammal Stranding Hotline is (877) WHALE-HELP (877) 942-5343). 

Contributing: Dinah Voyles Pulver, USA TODAY

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at [email protected] and follow her on X @nataliealund.