What we've seen is that with the water levels going down, the temperatures in the summer and the slight increase in temperatures is driving those warmer waters down deeper into the water column, so to speak. That collapses that narrow cold band on the bottom and makes it more shallow. In those sorts of cases in those particular years when it's very warm and that bottom layer collapses, we see lower and lower oxygen levels in the bottom of the water. The lower level of oxygen and how that's affected by temperature are certainly a concern to us.
On February 13th, 2014. See this statement in context.