Thursday, June 18, 2009

Big Hole Grayling Continue to Decline

The population of Big Hole River Grayling, the last self-sustaining native population of fluvial Arctic grayling in the contiguous 48 states, have declined by about half since 1990.

In 1990, Montana Fish, Wildlife & Parks electro-shocking efforts turned up 532 fish. In 2008, just 253 grayling could be found. Furthermore, the fish that are found tend to be larger and older, meaning that recruitment (successful spawning and young-of-the year survival) is declining. While a goodly portion of the 2008 fish were young-of-the-year, one swallow does not make a summer. Or, in this case, one good water year does not make up for the consistent, year-to-year dewatering of the river by irrigators.

While I applaud Montana FWP and the US Fish & Wildlife Service efforts to restore grayling habitat, it is all a matter of "Too Little, Too Late." For example, the small Steele Creek (named for homesteader Mike Steele) restoration project is the "showcase" restoration project. In 2008, 13.5 grayling per mile (GPM) were found in the Steele Creek. But in 2007 there were 23.0 GPM, and in 2006 36.1 GPM. In 2003, before restoration even began, there were 27.4 GPM.

The lesson: until Montana's fluvial Arctic grayling is listed under the US Endangered Species Act and greater restortion efforts are brought to bear (especially when it comes to keeping more water in the river), Big Hole River grayling will continue to decline.

For the future of Montana grayling, we can look to Michigan (image from


Source: Jim Magee, "Big Hole Arctic Grayling Conservation Efforts 2008," Montana Fish, Wildlife & Parks.