Brown Trout population numbers are dropping across a wide range of southwest Montana rivers. Biologists are stumped as to the cause, and a looming summer of drought is putting on the heat. It’s all hands on deck, and the experts are out for solutions.
LINK (via: Ravilli Republic)
Heat, I’d say. Browns like life rather cooler than rainbows. Certainly been my experience during my many years of fishing for them in their original home range, Europe and Scandinavia, where, when the waters warm markedly, the browns “move on up” to find cooler tempetures or gradually (or even all-go-belly-up in a we-can’t-take-this instant), die off, leaving their former home to the more heat-tolerant rainbows (stocked fish in my own country, Britain), then, when these start finding life too difficult, in comes stuff like the much more heat- and low oxygen-tolerant carp.. Same with Atlantic salmon as many have been finding in the more southern, non-Arctic rivers of its range over the past couple of decades.