While celebrating their 50th year of advancing fish science, members of the American Fisheries Society Montana Chapter gathered in Missoula worried that their public was wriggling off the hook.

“We tend to deliver a lot of wha-wha-wha, and then a blast of data,” AFS President Joe Magraf told about 400 biologists, fisheries managers and policy makers gathered at the group’s annual conference on Tuesday.

“We don’t express things well when talking to decisionmakers. The Clark Fork River was not a place you wanted to dip your toes into 50 years ago. Now it’s a great place to fish. That’s what fisheries biology is all about — creating places like Missoula.”

Looking back on that half-century of fisheries science, University of Montana Regents Professor Emeritus Fred Allendorf recalled how DNA analysis went from almost nonexistent to become a driving tool for biology.

It explains what happens, for example, when artificially stocked rainbow trout interbreed with native cutthroats in Montana streams. The first generation of mutts lose the cutthroats’ preference for sticking to the streams of their birth and instead spread to any water with good spawning habitat.

Subsequent generations produce babies that have even less cutthroat genetics, which contain the adaptive tricks cutthroats spent millennia developing to survive in mountain waters. Five generations down the line, the hybrids have lost 50 percent or more of their reproductive fitness. In other worlds, the unfit fish populations start to crash.

Allendorf said that scientific process nevertheless becomes controversial when it gets displayed as evolution. He cited public opinion surveys showing Americans ranked 33rd out of 34 developed nations for general acceptance of evolution theory, just above Turkey.

“We’re in a time when opinions have more effect on policy than facts,” Allendorf said. “This is really depressing as a science educator.”

The division doesn’t simply affect people’s social circles or politics, Allendorf argued. Trying to manage the rise in antibiotic-resistant tuberculosis requires an understanding of evolutionary principles. The practice doesn’t only explain the past, he said, but predicts the future.

Former Interior Department Deputy Secretary Lynn Scarlett added that the public often insists on including science as part of the problem, rather than a way of solving problems.

“No longer is our footprint just local or even regional,” Scarlett said. “Sometimes we are seeing changes to the whole planet.”

But that runs into the tension between science and decisionmaking, which often drags in old tug-of-wars decades removed from the problem at hand.

People will split on whether decisions should be local or federal, public or private, carrot or stick. It gets rocky when scientists describe a challenge like managing multi-state river systems to an audience suspicious of large-scale action.

Scarlett recalled her process in getting the polar bear declared threatened under the Endangered Species Act. The decision entangled local and national opinions on the bear’s importance, unsettled questions about what the bear needed to persist or thrive, and vested economic interests who benefited or suffered from the bear’s presence. The U.S. Fish and Wildlife Service eventually decided to list the polar bear.

“The decision survived five lawsuits,” Scarlett recalled. “And that was only because we made decisions on what science we used and were completely transparent.”