DIVIDE — The drought throughout Montana is affecting many of the fish living southwest Montana’s rivers.
The StoneFly fly shop co-owner Chris Bradley has been following the impact of the drought on the fish and rivers throughout Southwest Montana.
Bradley says he’s seen business trending downward earlier than normal—but his biggest concerns are dying fish and the low flowing rivers.
"We’ve been encouraging folks to adjust their fishing hours to go early, early in the morning, and be done early in the afternoon regardless of whether or not the river has actual hoot owl restrictions on them and it’s also been a great time to check out some of the high mountain and smaller creeks and things like that," said Bradley.
Montana Fish, Wildlife, and Parks (FWP) is looking into what’s happening in these rivers.
The Big Hole River Fisheries biologist Jim Olsen says that many of the new river closures are due to low flow triggers being hit. "So, not only is not very much water in the river, that water is really warm for cold-water fish."
Olsen says that the flow at the lowest part of the Big Hole river is 100 CFS or cubic feet per second. A normal flow would be 550 CFS.
According to the study “Effects of human-driven water stress on river ecosystems: a meta-analysis', low water flow is natural and many of the organisms in freshwater rivers can adapt to it for a temporary amount of time. But due to a mixture of drought, little rainfall, and heat, human demand water stress has a strong impact on river ecosystems- irrigation especially.
This stress is unnatural and affects water chemistry, algal biomass, the abundance, density, and richness of invertebrates, as well as ecosystem functioning.
"Normally, there’s plenty of water to meet both the agricultural needs and for the fish habitat. It's just this is a really dry, dry year so far," said Olsen.
Many fishing shop owners say that keeping the trout safe is their number one priority.