PORTLAND, Maine — Two common diseases, avian flu and distemper, may be to blame for a rash of seal deaths that caused dozens of them to wash ashore in Maine, New Hampshire, and Massachusetts in the biggest die-off of seals since 2011, federal scientists said Thursday.
Preliminary tests on the first batch of samples indicate the seals tested positive for avian flu and phocine distemper, but it's too soon to determine if either of both of the viruses were the primary cause of the seal deaths, the National Oceanic and Atmospheric Administration reported.
The bulk of the deaths have been off the Maine coast, with 244 seal deaths in July and August. Another 88 deaths were reported in New Hampshire and Massachusetts.
People and pets are being urged to call a NOAA hotline and keep a safe distance, 100 yards, if they encounter a sick or dead seal.
Scientists don't think the diseases pose a threat to humans, but it's too early to be sure, said spokeswoman Jennifer Goebel.
It's the largest number of seal deaths since 2011, when 784 seals died in Maine, New Hampshire and Massachusetts due to influenza.
Volunteers and staff from Marine Mammals of Maine have been working long days, and are still responding to reports of 10 sick or dead seals each day, said Lynda Doughty, executive director.
"There are heartbreaking cases," Doughty said Thursday. "We realize this could be the way the population is regulating itself."
In Maine, the average number of seal deaths for August is about 38, but the number already has reached 179 for the month, NOAA said.
Avian flu and distemper found in the first batch of seals has been associated with past seal dieoffs.
Further evaluations will continue over the next several weeks to months as additional seals are found or new evidence determines the direction of the investigation. The investigation may take several more months to complete, officials said.