Boat Exhaust Fumes Harming West Coast Killer Whales
Friday, March 11 2011 @ 12:40 AM EST
Contributed by: karenbills
Just 87 orcas remain in the southern gulf between Seattle and Vancouver
Engine exhaust from boats may be having significant adverse health effects on endangered killer whales off the West Coast, a Canadian zoologist has found.
A two-and-a-half year study by Cara Lachmuth suggests that the orcas may be struggling with carbon monoxide emissions five times higher than those found 100 meters (328 feet) from Los Angeles freeways.
Lachmuth used computer modeling and mathematical equations to recreate various scenarios of exposure to pollutants. She then proportionately compared acceptable levels of toxins on humans to whale populations.
“There are different concentrations of pollutants under a wide variety of scenarios that I was able to recreate, and then I used those concentrations to figure out health-wise what that means to a killer whale,” said Lachmuth, of the University of British Columbia’s Department of Zoology.
She found that when cold ocean surface temperatures meet warm air, an inversion layer is created that prevents vertical airflow. This means the air can only move horizontally and keeps the pollutants close to the surface, accumulating right where the whales are breathing.
Read the rest of the story here including quotes by David Hancock: