Danged salmon. Salmon as vectors. Whooda thunk? Seems they may be ferrying industrial pollutants northward to people and wildlife in Alaska's interior lakes, according to research published in Nature's September 18 issue and reported by Anahad O'Connor. It's just a small quantity of PCBs we're talking here, O'Connor assures. But when the fish die together in the thousands, their decaying carcasses produce a seven-fold increase in the PCB concentrations of the spawning lakes, the study found. Study author Jules Blais, assistant professor of biology at the University of Ottawa: They die in such huge numbers that it almost looks like you can walk across the lakes. O'Connor's article: The salmon act as biological pumps, Dr. Blais said, carrying pollutants upstream where they can reach bears, eagles and people whose diets consist mainly of fish, seals and whales.