Dead Whale Appears to Be Bay Area’s ‘Petaluma Pete’

A young whale found dead in a shallow bay appears to be “Petaluma Pete,” who charmed residents by escorting ferry boats and swimming up the Petaluma River, a biologist said Wednesday.

The whale had repeatedly stranded himself in San Francisco Bay since his initial sighting last month at the Larkspur ferry terminal, said Hilary Feldman of the Marine Mammal Center.

She said he most likely died because he became lost after detouring into the bay during the annual swim to Alaska.

“He was a young whale, and that whole migration route is a long way,” she said. “This was likely the first year he was doing it alone.”

Because of the dead whale’s condition, it was difficult for scientists to be certain that it was Petaluma Pete. But the dead whale had the same distinctive marking on the pectoral fin, prompting experts to say they are 99% sure it was the same creature.

The young whale probably entered the bay, swimming first north to Petaluma, then south as he tried to find his way out, but he missed the Golden Gate entirely, Feldman said.

“It’s an awful small opening for a big bay--even humans have trouble finding it,” Feldman said.

The whale was found dead after beaching itself on mud flats near Santa Clara on Memorial Day weekend, and its carcass was taken to the center for a necropsy.

It was first spotted off Larkspur, then Petaluma, and finally Santa Clara. Onlookers in the crowds that gathered to observe its wanderings on the Petaluma River variously dubbed it either Pete or Phyllis because they were unsure of its sex.

The dead whale was male, between 1 and 2 years old, and weighed six to eight tons.

The immediate cause of death was congestive pneumonia, which could have been caused by virus or bacteria, Feldman said.

“But one of the things that can lead to congestive pneumonia is repeated strandings,” she said. “This whale was left high and dry six or seven times as the tide went out.” That puts a crushing weight on the whale’s internal organs, she said.

The whale had not eaten for at least five days before his death, and his body fat was being used up.