Hot weather is killing fish
August 6, 2012
The heat wave and drought have been unpleasant for most people, hugely damaging to crops, and deadly for fish in many Midwestern streams and rivers
. The less precipitation that falls, the more river levels drop. The Platte River in Nebraska is virtually bone-dry at Grand Island. Even in places where water still flows, high temperatures are placing stress on fish and killing many. Believe it or not, the problem often is that fish suffocate
in warm waters, because the solubility of oxygen in the water declines as temperatures rise. And, just like mammals breathe (or pant) more in the heat, many aquatic species need more oxygen as their bodies heat up as well, which only depletes oxygen levels in the water even further.
One of the key steps taken in municipal wastewater treatment
is aeration -- the mechanical addition of oxygen to the water, often by diffusers
, but also sometimes through other means like rotating biological contactors
. Accurate measurement of dissolved oxygen
is important for managing the treatment of wastewater and the protection of the streams that receive the treated water.