Whale experts are investigating what could be the death of a second North Atlantic right whale in U.S. waters this year.

On Thursday, the stranding response program at the Virginia Aquarium was alerted to a "very decomposed large whale carcass."

The remains washed ashore on Metompkin Island in Virginia, near the Maryland border.

"Whale experts have tentatively identified it as a North Atlantic right whale," the U.S. National Oceanographic and Atmospheric Administration said in a news release. "Genetic samples have been taken to verify this finding."

If confirmed, it would be the second death of an endangered whale reported in 2018. The first was reported in January off the coast of Virginia.

Since January 2017, there have been 18 deaths of North Atlantic right whales in U.S. and Canadian waters — 12 off the Canadian coast and six off the U.S. The whale found this week would be the 19th.

The remains of what appears to be a North Atlantic right whale washed ashore on Metompkin Island in Virginia, near the Maryland border (Submitted)

Canadian officials said there have been no reported deaths in Canadian waters this year.

It's suspected that many of them died after getting ensnared in fishing gear or hit by large vessels.

To date, there are only 100 breeding females remaining in a population of about 450 North Atlantic right whales.

Whales back in the gulf

Births have also been declining in recent years, and no new calves were spotted in the calving grounds off Florida this year.

Up to 75 right whales have been spotted in the southern part of the Gulf of St. Lawrence so far this year, officials said.

Since the beginning of the fishing season for lobster, snow crab and other species, the federal government has closed six fishing areas because of the presence of whales.

Fisheries officers have retrieved gear from areas closed to fishing and are investigating, said Darren Goetze of the Department of Fisheries and Oceans.

"It will be part of the investigation to determine if navigational errors might've contributed to the placement of gear," said Goetz, who is with the conservation and protection division.

"The number of traps is not significant in proportion to the total amount of gear in the water."

Fishing closures in Canada

The latest closure includes a shallow coastal area where fishermen are seeking permission to drop their traps — resulting in nearly 500 lobster fishermen who protested in Caraquet on Thursday.

A map showing where the fishing area closures are located. (CBC )

The closure was originally set for late Friday afternoon but will now begin Sunday at noon because of strong winds and concerns about safety, the Fisheries Department said.

The fishing closures are among the steps taken by the department to try to save North Atlantic right whales. The steps also include rules that ships slow down in some areas.