Move over, Orca whales: new study of Pacific White-sided Dolphin

The SeaDoc society thinks it's time for orcas to move over and share the spotlight. SeaDoc has hired marine science PhD student Erin Ashe to analyze thousands of dolphin photographs from Washington and British Columbia, identify the dolphins and determine the size and nature of the population.

Killer whales, look out: the Pacific white-sided dolphin has a lot of spunk.

They’re small, weighing in at 200 to 300 pounds, but they swim in large groups of one to two hundred.

And if 10,000-pound resident orcas get in the way while the dolphins are feeding, there will be a bit of a scuffle.

“I saw that when I was up in the Broughton Archipelago,” said SeaDoc Society director Joe Gaydos. “The dolphins were just zooming in and out and hopping over the top of the killer whales and harassing them.”

Killer whales have gotten the lion’s share of the attention in recent years; every resident pod member is now photographed, named and anxiously observed from birth to death.

The SeaDoc society thinks it’s time for orcas to move over and share the spotlight.

SeaDoc has hired marine science PhD student Erin Ashe to analyze thousands of dolphin photographs from Washington and British Columbia, identify the dolphins and determine the size and nature of the population.

In 1976 the National Marine Fisheries service initiated “Orca survey,” a long-term photo-identification study of southern resident killer whales in the San Juan Islands. The project’s goal was to determine the size of the killer whale population in the greater Puget Sound area.

“We’re using the same technique on a related species,” said Gaydos. “Because the (pacific white-sided dolphin) population’s not really listed as threatened or endangered, we don’t really have any data… We don’t even know if the population’s declining or stable right now.”

The only legislation that currently protects the dolphins is the general Marine Mammal Protection Act. The society intends to discover whether the dolphins are being adequately protected and thriving.

“All of that hinges on having a good idea of the population,” said Gaydos. “That’s the main goal.”

By analyzing the photos, Gaydos said Ashe will be able to identify the dolphins based on individual dorsal fin markings, allowing her to calculate their life spans, range of travel, reproductive habits and more. Ashe grew up on San Juan island and is now studying at Scotland’s St. Andrews University.

More photographs needed

Gaydos said Ashe still needs more photos of pacific white-sided dolphins, especially clear shots of dorsal fins. Good condition photos from any date are useful. Email your photos to Ashe at dolphins@oceansinitiative.org. Information on the location, date, size of the dolphin group, presence of babies or other data is also appreciated, but not required.

“We’re going to learn something about a really cool species,” said Gaydos.

We think the white-sided dolphins would agree.