PROVINCETOWN (CBS/AP) — Surveyors say a North Atlantic right whale mother and calf have been spotted in Cape Cod Bay for the first time this season.

The whales are the focus of conservation efforts because of their declining population. There are only about 411 of the marine mammals, and they’ve suffered high mortality and poor reproduction in recent years.

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The Center for Coastal Studies in Provincetown says the mother and calf were seen Saturday by surveyors from the Northeast Fisheries Science Center. Surveyors in an airplane saw them again Sunday.

Right whale #1204 with her 2019 calf in Cape Cod Bay on April 7 (Photo credit: Center for Coastal Studies)

The Cape Cod Times reports the calf was first seen Jan. 17 off the southeastern U.S.

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It’s the third of seven calves documented this season.

In another weekend whale sighting, the drone video seen above showed a whale splashing and rolling in the waters off Cape Cod.

The whales arrive in late winter and early spring in New England waters to feed and socialize.

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(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)