A new report shows that the southern population of endangered killer whales in the Pacific Northwest are the most The salmon swim in Pacific near-shore waters polluted by agriculture, industry, and regular ol' urban runoff. The researchers found that 97 percent to 99 percent of contaminants in the salmon eaten by these whales originated from the salmon's time in the sea. The contaminants include persistent PCBs, which suppress the immune systems of marine mammals. But wait a minute -- aren't we eating these salmon, too? Yes, just not at the same pace -- the whales eat more than 500 pounds per day. At this rate, the outlook is not looking great for the remaining 83 whales in the southern population.