Female Hybrid Porpoise on Beach at American Camp

Preparing for the Necropsy

Hybrid Porpoise Fetus

On May 21, the San Juan County Marine Mammal Stranding Network (SJCMMSN) received a call from the National Park Service of a dead porpoise on one of their pocket beaches at American Camp. Upon investigation, it turned out to be a female hybrid porpoise in excellent condition. The carcass was recovered, brought to the Friday Harbor Labs, and necropsied by Joe Gaydos on Monday morning. The necropsy didn’t reveal any obvious cause(s) of death, but she was carrying a third-trimester fetus.

Hybrid porpoise – crosses between Dall’s and harbor – have been documented in the Salish Sea, British Columbia, and SE Alaska for many years. They appear to be offspring of a Dall’s female and a male harbor porpoise and, therefore, are found traveling with Dall’s porpoise.

Amy Traxler, Coordinator of the SJCMMSN, says: “This was an incredible find! As far as I know, we’ve never recovered a hybrid porpoise here in San Juan County and, although we’re still searching the literature and contacting other researchers, we believe this may be the first pregnant hybrid porpoise that has ever stranded.” Further testing on this porpoise will be conducted including genetic testing on both mom and fetus , as well as skeleton comparisons to both species of porpoise.

As always, please call the SJCMMSN's toll-free number whenever you find a marine mammal shore live - dead or alive - at 800-562-8832.