The future of
BLUE SUCKERS By Erin Madison
NorthWestern Energy and our partner agencies are studying why juvenile blue suckers seem to be missing from the population. Photo by Z. Shattuck, Montana FWP
It’s likely that some of the blue sucker fish found in Montana’s Missouri River could be nearly 70 years old. However, young blue suckers seem to be missing. “In the last 23 years, we have not observed any young blue suckers,” said Grant Grisak, Biologist with NorthWestern Energy. Blue suckers are considered a species of special concern in Mon-
netting, seining and trawling. We’ve also surgically implanted radio transmitters in adult fish to follow their movements throughout the year. “We look at their behavior and try to make some determinations about what those fish are responding to during the winter time, during the summer or during their spawning season,” Grant said. “We’re building a picture of what their behavior is like.”
tana and are specifically listed in our fisheries monitoring plan, part of
However, through all of those monitoring techniques, biologists are
the federal license that allows us to operate dams on the Missouri and
not finding any juvenile blue suckers. That could be because the pop-
Madison rivers. Blue suckers are found in the Missouri River, downstream
ulation is so low that there aren’t enough adult fish to get together and
of Morony Dam, our most-downstream dam on the Missouri.
spawn, Grant said, or the conditions in the river aren’t allowing young
For more than 20 years, biologists with NorthWestern Energy, Montana Fish, Wildlife & Parks, and other agencies have been monitoring these fish through a variety of techniques designed to sample a broad
fish to survive. “We don’t know where this bottleneck might be,” Grant said. “That’s the question we’re trying to answer.”
range of habitats and sizes from newly hatched fish to adults. We’ve
NorthWestern Energy and Fish, Wildlife & Parks are now using a fish
surveyed the blue sucker population through electrofishing, trammel
aging technique that was used to determine the age of several bigmouth
22 | BRIGHT MAGAZINE Vol. 3
