I'm going to ask my question and thus take the Liberal Party's turn.
Dr. Schindler, in the data that you showed us, could you just explain to me again what it's showing? It's showing that there are more chemicals in the river than there would be naturally, especially around oil sands developments, and then of course it tapers off as we go down the river. You were saying some of that presence of chemicals, as I understand it, comes from airborne sources, from the operations of maybe the disturbance of the natural ecosystem, and that some has come through the water as well. Have you speculated as to the source of the water-borne chemicals, if you will? Would that be tailings ponds? Are you prepared to make that link, or is it up in the air?