You will probably never catch Montana’s newest fish species, but the small fash called cisco are the secret to those big fish you hope to catch.
Fort Peck Reservoir produces some big fish -- from salmon to lake trout to walleyes. Fish biologists say the secret to these large fish are cisco.
"Looking particularly at walleye, the size structure changed after cisco were established. We started seeing more fish over 25", close to 30", and it really changed the dynamics of the fishery," said Health Headly with Montana Fish, Wildlife and Parks.
Cisco, also known as lake herring, were stocked in Fort Peck in 1984. Found only near Glasgow and in Tiber Reservoir, this non-native plankton eating fish is the equivalent of a double bacon cheeseburger to the popular game fish anglers seek.
"Definitely providing a lot of nutrients out there for those bigger fish and that’s why we see 30" walleyes on an annual basis out here on fort peck -- and big lake trout, big pike and big salmon," Headly said.
Even though the reservoir’s cisco population can be cyclical, the last six years has seen a cisco boom, according to Headly.
"These last few years we have seen good reproduction, but really, we’ve seen our pike, our walleye, lake trout, salmon, all those larger predatory species are kind of at or above long-term averages. So, they are eating them and they are utilizing them."