From Hakai Magazine
by Starre Vartan
When a wildfire rages, some animals fly, hop, or run to safety. But fish can’t.
During a fire, the temperature of a stream or river will sometimes rise to a lethal degree. If a fish survives without being cooked, short-term changes to its environment might finish it off. Denuded stream banks erode quickly, with topsoil and ash clouding streams and making it difficult for fish to breathe or find food. Even firefighting efforts are a threat: foam fire suppressants can suffocate fish, while fire retardants can be toxic.
Following those immediate threats, wildfires can also change a fish’s habitat for months and even years. If trees that once provided shade burned down, that stream’s water could heat up enough to make it unsuitable for cold-water fish, such as trout. Heat is particularly dire for eggs and fry.
Not surprisingly then, in the weeks and months after a wildfire, “fish populations will decline, sometimes dramatically,” says Rebecca Flitcroft, a fish biologist at the US Forest Service. Flitcroft points out that as populations, many animals, including fish, have evolved to survive severe, shorter events such as fires even if their numbers temporarily decline. continue reading here