Dead right whale's mother escaped injury

BOSTON — North Atlantic right whale researchers are breathing a little easier with recent sightings in Canadian waters of the female named Punctuation, the mother of the male calf that was killed by ship propeller cuts in early May east of Cape Cod.

“That was sort of a quiet concern, whether the ship that killed her calf might have injured her,” New England Aquarium Research Scientist Phil Hamilton said. “Traveling together, close together, you never know.”

Earlier this year, the aerial survey team at the Center for Coastal Studies in Provincetown had kept watch over a group of mother-calf pairs in Cape Cod Bay including Punctuation and the male calf that was killed in May. "I was kind of thrilled that Punctuation was OK," center right whale habitat expert Charles "Stormy" Mayo said. "That was such a brutal ship strike. The calf never knew what happened, never knew what hit it. I was really fearful that she would have been struck too."

The center's aerial survey team had last seen the 30-foot calf alive on April 28, swimming in Cape Cod Bay. The calf was Punctuation's eighth one, National Oceanic and Atmospheric Administration records stated. The calf’s body, with nine ship-propeller cuts and fractured bones, was found floating May 5 off Morris Island in Chatham, and a NOAA investigation determined that the calf died from being struck by a vessel.

The strike of the calf was most likely from a big ship east of Cape Cod, and of a magnitude that it could have killed Punctuation as well, Mayo said.  

"It was a big relief," Mayo said. "It’s a Center for Coastal Studies whale since we saw so much of her. Hopefully she’ll have other calves."

Researchers in Canada saw Punctuation on July 30 and Aug. 1 in the northern part of the Gulf of St. Lawrence, and on Saturday in the St. Lawrence River estuary near Rimouski, Quebec, Hamilton said.

“This is a critical time for breeding females,” Hamilton said. “Females who have been nursing for eight months. They are seriously depleted. They’ve lost a third of their body weight, calving and nursing. They produce a lot of milk for that calf. You can see how thin they’ve become.”

The Bay of Fundy and increasingly the Gulf of St. Lawrence are areas where ribght whales appear to be feeding, Hamilton said. “It seems to be a habitat of growing importance.”

The calf that was killed in May was one of 14 born over the winter off the southeastern U.S. coastline, Lisa Conger, a biologist with a NOAA large whale team in Woods Hole, said. Another calf is missing as well, based on comparisons of mother-calf pairs in the southeastern calving grounds versus the pairs seen in the feeding grounds in Cape Cod Bay, Conger said.

A criminal investigation into the death of Punctuation's calf was closed in July due to a lack of evidence, a NOAA Fisheries Office Law Enforcement spokeswoman said.

North Atlantic right whales are considered critically endangered, with about 500 left in the world. The whales are protected under the U.S. Marine Mammal Protection Act and the U.S. Endangered Species Act.

— Follow Mary Ann Bragg on Twitter: @maryannbraggCCT.