Recent Birch Bay gray whale sightings worry wildlife experts

For about a month from mid-June to mid-July, at least one gray whale explored Birch Bay, feeding in the muddy, shallow waters. While the visit was exciting for those who spotted the whale breaching in the bay, it may be an ominous sign for the eastern North Pacific gray whale population.

The eastern North Pacific population, which migrates between Baja California and the Arctic, is going through what scientists call an unusual mortality event. As of July 18, 103 dead gray whales had washed ashore from Alaska to California this year, according to a National Oceanic and Atmospheric Administration (NOAA) fact sheet, and scientists think that’s only about 10 percent of the deceased whales.

Many of the dead gray whales studied show signs of malnutrition. The whale that appeared in Birch Bay was likely trying to find more food before continuing its migration north, said Victoria Souze, principal investigator for the Whatcom Marine Mammal Stranding Network (WWMSN).

Gray whale sightings aren’t unheard of in local waters – three gray whales stopped in at Birch Bay in early May 2017 – but July is an unusual time to see whales this far south, Souze said. Most gray whales leave their winter birthing grounds in Mexico between February and April, and by July should be much farther north, she said. Gray whales do most of their annual feeding in Arctic waters.

The whale may have left Birch Bay – as of July 23, no one had reported a sighting in three days, but Souze cautioned that whales in the Salish Sea this late in the year are stressed and should be given plenty of space.

While the whale was in Birch Bay, drones, boats, kayaks and paddleboards got far too close, violating marine life viewing guidelines established by NOAA, Souze said.

“They need to stay away because it’s harassment and it can disturb their feeding behavior,” she said. “At this point they don’t need any more stress from noise and boats.”

According to NOAA’s guidelines, one must not feed, swim with, ride, pet, touch or attempt to interact with marine mammals. When viewing whales by watercraft, one must remain at least 100 yards away – about the length of a football field. In addition, one must not chase or encircle whales with any watercraft, and must avoid excessive speed or sudden changes in direction.

When viewing whales from the air, a 1,000-foot minimum altitude must be maintained. “Avoid flying drones, or unmanned aircraft systems, near animals,” NOAA’s website states. “The noise and close proximity of drones can harass the animals and cause stress.”

Scientists don’t know why so many gray whales are dying, but they have some ideas. NOAA estimates that there are currently about 27,000 eastern North Pacific gray whales, which is a historic high. The population may just be too big for the ecosystem to support.

Scientists are also exploring the effects of warming Arctic waters on the shrimp-like amphipods and surface-dwelling small fish the whales eat.

The last unusual mortality event for gray whales was in 1999-2000. That was an El Niño year, which affected food supply, and it was also a time when the gray whale population was near historic highs. The cause of that mass die-off was never entirely determined.