Little research has been done on how marine mammals are affected by prolonged exposure to the smoke and chemicals released during wildfires, but if the aftermath of the Deepwater Horizon oil rig explosion in the Gulf of Mexico is any indicator, they could face serious health effects in the years to come.
Ten years ago, as a first responder in New Orleans, veterinarian Cara Field saw for herself how the worst oil spill in U.S. history affected the region’s wildlife. The spill released 200 million gallons of oil into the ocean, much of which rose to the surface. As part of the cleanup, crews burned it off into the atmosphere. But research just five years later showed bottlenose dolphins that breathed the chemical-laden smoke developed severe lung diseases, were more prone to infections, and their offspring died at higher rates.
Field, now the medical director at the Marine Mammal Center, a conservation nonprofit in Sausalito, California, fears that marine mammals along the western coast of North America could be facing a similar fate, during a season of disastrous wildfires that have destroyed more than seven million acres.
Wildfire smoke is made up of a range of gases, including carbon monoxide; nitrogen dioxide; polycyclic aromatic hydrocarbons, or PAHs; and hazardous particulate matter, which has been shown to increase risks of respiratory and cardiovascular illnesses in humans.
Because whales, dolphins, porpoises, and other marine mammals are adapted to life at sea, where there are fewer air pollutants than on land, they “would be expected to be more susceptible to injury from inhaled particulates,” Field says. That could have grave consequences for species such as sea otters and orcas, or killer whales, which are already in decline in the region. (Read how the Exxon Valdez spill devastated orcas.)
Because the effects of wildfire smoke on marine mammals aren’t well understood and the potential threat is high, Field is urging scientists along the West Coast to begin collecting data now on marine mammal health in areas affected by wildfires. Though there have not been reports of stranded marine mammals suffering from smoke inhalation this fire season, it’s still possible, Field says.