45-foot humpback whale carcass washes ashore in Sandwich

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SANDWICH, Mass. — Onlookers watched as wildlife officials surrounded a dead humpback whale with caution tape on a Sandwich beach on Tuesday morning.

The massive, 45-foot mammal, listed as an endangered species, was first spotted on Stellwagen Bank on Saturday afternoon, but its carcass only washed ashore days later.

Identified by researchers as "Vector," a mature female humpback first cataloged in 1984, the whale had been seen regularly, at least once a year for the past 15 years.

The International Fund for Animal Welfare (IFAW) says Vector's necropsy to determine the cause of death is planned for Wednesday.

Vector has birthed five calves and has been observed in many areas of the Gulf of Maine, from Massachusetts to Nova Scotia.

Humpback whales have been classified as an endangered species under the Endangered Species Conservation Act since 1970 and then under the Endangered Species Act in 1973.