Bull trout on the brink of extinction in the Flathead?

Recently, in opinion pieces published in many area newspapers and on numerous Web sites and blogs, Montana Trout Unlimited once again declared loudly and publicly that bull trout are on the brink of “extirpation” and that gill netting (killing) hundreds of thousands of lake trout will be the only thing that can save them. As I have said in the past, many of these published pieces are long on emotion and short on facts.

The Flathead system changed dramatically in the mid-1980s when mysis shrimp were discovered in the lake, forever and radically changing the food web complex (”State of the lake 2009,” Jack Stanford, Flathead Lake Biological Station). In this analysis, Dr. Stanford also states that the increasing temperature of the lake is “too warm for cutthroat to grow.”

Any ideas and notions that native bull trout populations will ever again return to the pre-mysis populations have been forever dismissed by the majority of scientists who have ever studied the system, and the warm upper layers of the lake make it impossible for cutthroats to survive.

Fish, Wildlife and Parks and U.S. Fish and Wildlife Service biologists have established that the current adult bull trout population in the system is approximately 3,000, about half of the average before mysis shrimp was introduced. However, that is now more than double their lowest levels when every biologist was predicting they would be gone forever. They are also 50 percent above the “secure” level of 2,000 spawning adults.

It is also important to note that, when the Hungry Horse Dam was built, approximately 40 percent of the Flathead system’s historic bull trout populations and habitat were forever retained in the upper South Fork reaches, or forever protected from predation by introduced, non-native species.

The bottom line? The bull trout are recovering, they have stabilized, and the sky is not falling. The Confederated Salish and Kootenai Tribes and Trout Unlimited argument that bull trout face extinction in the Flathead system just does not currently have a biological or scientific basis — unless you feel that FWP’s 30-plus years of bull trout study is invalid.

The other part of the CSKT/TU argument says killing lake trout will help native fish. Locally, a three-year gill netting “experiment” on Swan Lake has shown, without a doubt, that you can kill lake trout. Conversely, in Swan Lake over the three-year course of gill netting, the bull trout redd counts have dropped drastically. Is that due to by-catch mortality? Leaders of this study have said that they are very concerned over this result, so pointing to Swan Lake as a success, for anything other than killing lake trout, again has no current scientific basis.

In 2011 alone, more than 230,000 lake trout were removed from Yellowstone lake (netting began in 1994), yet the best they can say is that number could be approaching the level needed to bring back populations of Yellowstone cutthroat trout. (After 17 years, netting has not increased the native fish populations, and in fact, the lake trout population has increased.)

The emotionally charged yet scientifically lacking arguments that are being presented only stand to serve the people who will receive the dollars to conduct this netting experiment. There are reasons we have environmental impact statements and NEPA and MEPA processes, and support of this action without them is premature.

Mike Howe lives in Kalispell and is the host of Flathead Outdoors Radio.