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Lake fish facts are stubborn things

by Chris Schustrom
| May 2, 2012 7:32 AM

President John Adams famously said, “Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence.”

This quote was mentioned recently in reference to the process currently underway that seeks to balance the nonnative lake trout population in Flathead Lake with declining native bull trout and westslope cutthroat populations on which lake trout prey.

In 1998, when the Flathead Lake Co-Management Plan was being drafted, through a collaborative effort, the scientific evidence, or facts if you will, were essentially the same as they are today. The main difference today, after 12 years of co-management, being that management tools in the plan have failed to increase native fish numbers. There are more than twice as many lake trout today, and native bull trout populations continue their declining trend.

The independent panel of scientists assembled in 1998 to review the plan questioned the definition of “secure” for native bull trout populations as inadequate. Scientists involved in the process today continue to question the definition of “secure” given the recent losses, and imminent losses, of distinct, genetically unique populations that help the overall population survive in the event of forest fires, floods, changing weather and unforeseen habitat loss. Facts are stubborn things.

This conversation about secure and stable populations should take place among knowledgeable scientists involved in this process to restore native fish, not as cherry-picked information being used as a means to sway public opinion.

An example would be the picking of 50,000 to 130,000 as a range for the overall bull trout population in the Flathead. Scientists who put these numbers together, explained that these numbers represent estimates of the lowest number on record (1996) and the highest number on record (1982) of bull trout smolt production in the North and Middle Forks of the Flathead.

Smolts are juvenile bull trout that begin the migration from spawning streams to Flathead Lake. The real numbers are 36,000 (1996) and 150,000 (1982) smolts. Less than 1 percent of these fish will survive to adulthood.

One can easily arrive at completely different conclusions using these same numbers. For instance, these numbers also tell us that from 1982 (pre-lake trout population explosion) to 1996 (post-bull trout population crash as a result of this lake trout explosion), bull trout smolt production fell precariously by 76 percent.

Facts are stubborn things, and no matter which parts one might like to pick out, the overall reality remains the same. Native bull trout and westslope cutthroat populations continue a downward trend in the Flathead. You can, of course, review the facts and reach different conclusions. The danger lies in ignoring the science altogether and forming conclusions based solely on speculation. Future generations of anglers only stand to lose more if nothing is done.

We are fortunate to have well-qualified independent biologists, water quality experts, aquatic scientists and economists working on this inclusive project to restore symmetry to fish populations that are badly out of balance in the Flathead.

Those who have been choosing to cherry pick information for use toward their own ends should leave the cherry picking to the producers along Flathead Lake who grow the best cherries in the world. Future generations of Montanans will be better served by it.

Chris Schustrom is an advocate for native fish restoration who lives in Whitefish.