This is one tough whale.

A critically endangered North Atlantic right whale — known to researchers as No. 5192 — has survived multiple potentially deadly encounters with fishing gear, and despite being declared near death four years ago is still swimming.

The 5-year-old whale was spotted tangled in fishing gear off Barnegat Inlet, NJ, on Oct. 10, according to the National Oceanic and Atmospheric Administration (NOAA).

He’s been on a federal list of dead and dying whales for four years but apparently nobody’s told him.

“We’re aware of a sighting of North Atlantic right whale #5192 swimming off of Barnegat Inlet, New Jersey, on October 10,” NOAA spokesperson Ava DiFabritiis told The Post. “Stranding network partners and survey teams along the East Coast have been alerted and are awaiting new reports of the whale’s location.”

The amazing mammal has somehow survived despite repeated encounters with potentially deadly fishing gear that put him on NOAA’s Whale Morbidity Case list, which tracks doomed whales with life-threatening diseases or injuries.

The wandering whale’s troubles began in December 2022, when he was just 1 year old. Researchers spotted him off Southern New England with wounds consistent with a fishing gear entanglement and added him to NOAA’s morbidity records, according to the agency’s report.

But No. 5192 kept swimming – and growing.

A 5-year-old North Atlantic right whale can weigh roughly 20 tons and measure 35 feet long.

Incredibly, he popped back up on NOAA’s radar this year. On April 14, he was photographed swimming free of fishing gear in Cape Cod Bay, Mass. A week later, on April 21, he was spotted again in Massachusetts Bay, still free of gear.

But disaster was just around the corner.

On June 8, aerial observers spotted him in Canada’s Gulf of St. Lawrence, dragging fishing line along the left side of his mouth. The line extended beyond his tail and disappeared into the water.

Two days later, he was spotted near Canada’s Magdalen Islands.

The Department of Fisheries and Oceans Canada (DFO) attempted to mount a rescue and attach a satellite tag to No. 5192, but failed because of bad weather and rough ocean conditions.

NOAA scientists again put him back on the list of Unusual Mortality Events.

But No. 5192 kept on swimming.

In September, researchers spotted him off Montauk, N.Y.

All told, the mighty but purportedly dying whale swam about 700 nautical miles to get from the Gulf of St. Lawrence to the Jersey Shore.

But it has not been seen since Oct. 10 — and that has rescuers worried.

“We will continue to work with trained and authorized entanglement responders to monitor and document this case, and assess potential interventions,” said Fabritiis, who warns members of the public to call experts if they spot him and to “stay a safe distance from the whale until authorized professional responders arrive, and provide any photos and videos to NOAA Fisheries.”

No. 5192 even has a family waiting somewhere in the Atlantic. He is the great-grandson of “Wart,” No. 1140, a well-known right whale with a large family tree.

His mom Millipede (No. 3520) is alive and raising her third calf, and was spotted in Cape Cod Bay in March, according to a Center for Coastal Studies report. Just one week after No. 5192 was seen in the same spot.

NOAA’s Unusual Mortality Event began investigating right whale deaths and injuries in 2017. To date, it has counted 176 whales — 43 dead, 41 seriously injured and 92 sick or otherwise injured.

Only about 380 North Atlantic right whales remain, including roughly 70 reproductively active females. Fishing gear entanglements and ship strikes are among the greatest threats.