The Columbia Basin Bulletin points out an interesting study that shows just how pollution makes it through the food chain:
Seabirds nesting in Puget Sound consume fish, including Columbia River salmon, far more contaminated by long-lasting urban pollutants such as PCBs and flame retardants than seabirds feeding on the outer Washington coast, according to a new study led by researchers at the Northwest Fisheries Science Center.
Among the most contaminated fish detected in the study were chinook salmon. Three of 10 chinook salmon from Protection Island exceeded PCB thresholds for adverse health effects on fish and two of the 10 carried concentrations of PBDEs associated with increased susceptibility to disease in yearling chinook salmon.
One surprise was the elevated levels of POPs in salmon from the Destruction Island colony on the outer Washington coast. Two of the three chinook salmon from Destruction Island had PCB concentrations similar to fish from interior Puget Sound and other polluted sites. Those same fish also had the highest PBDE levels recorded in the study, far exceeding levels linked to increased susceptibility to disease.