CLARK FORK BASIN – STATE OF THE FISHERIES

Chris Clancy

Montana Fish, Wildlife and Parks

The condition of the Clark Fork Basin fishery is best described as mixed. While some areas are improving, others are in considerable trouble and likely getting worse. But positive actions are increasing, including community and landowner-supported stream restoration efforts and use of conservation easements to protect and enhance native fish populations. These positive actions struggle to reverse the negative effects of historic land uses and management while protecting the fishery from growing new threats. In particular, urbanization impacts increasingly demand action by FWP biologists.

Although the mainstem’s recreational fishery is dominated by introduced rainbow and brown trout, the importance of native species to the river’s health is increasingly recognized by the fisheries profession and the public. Overall, populations of some native species are increasing--most likely due to more restrictive fishing regulations in several areas. In the past decade, angler use of most of the basin’s rivers has increased dramatically--a development that has both positive and negative impacts.

A short summary of MFWP’s fishery restoration and protection efforts in the subbasins illustrates the variety of issues we face:

Upper Clark Fork (above Milltown Reservoir)

The mainstem fishery is well below its potential. It’s overriding problem is the multiple impacts of mining—everything from instream contamination to streambanks destabilized by their inability to support adequate riparian vegetation. The impacts of metals pollution are exacerbated by dewatering, streambank grazing, channelization, and excess nutrient loading. While some of the tributaries support good populations of westslope cutthroat and bull trout, the mainstem population is almost entirely metal-tolerant brown trout. Unfortunately, settlement of the upper basin’s complex Superfund issues requires far more time than area fisheries biologists are able to give, for their time is absorbed in stream project permitting, recreational angling issues and other routine MFWP responsibilities. Hopefully with NRD funding, MFWP will be able to put more resources into stream restoration. Presently, MFWP is focusing on restoration projects in Rock Creek and in the area of Warm Springs and Lost Creeks near Anaconda. (see our poster for info on these projects).

Rock Creek is the bright spot in the Upper Clark Fork. It still supports good populations of migratory bull and cutthroat trout as well as rainbow and brown trout. Our efforts in Rock Creek are focussed on developing restoration opportunities and supporting Forest Service efforts to do the same. We manage this splendid recreational fishery but would like to have the resources to give it more attention.

Milltown Dam

With support from Montana Power and agency funds, we have focused on the fishery impacts of Milltown Dam. It is a barrier to upstream movement of migratory fish and has become a core area for illegally introduced northern pike that likely migrated down from the Clearwater chain of lakes.

Due to Milltown Dam’s impacts and limited benefits, MFWP supports eventual removal following other necessary actions to reduce impacts of removal.

Blackfoot River (including Clearwater chain of lakes)

This is the shining star of restoration efforts by MFWP, the US Fish and Wildlife Service, private partners and other government agencies. MFWP has clear goals and objectives focused on stream restoration. Much effort has gone into naturalizing streams in the past 10 years, and that effort will continue. Funds from multiple sources have made it possible to undertake stream restoration work while other FWP biologists have assumed responsibility for permitting and lake management in the drainage.

Observed increases in native fish populations in the Blackfoot mainstem are likely due to tighter fishing regulations, while increases in Blackfoot tributaries are mainly due to restoration efforts.

A new threat--whirling disease--is increasing within the range of rainbow trout in the drainage even as recreational fishing pressure continues to rise. Historic mining impacts are still causing water quality and fisheries problems as are other historic land use practices.

Recently, the largest fisheries impact on the Clearwater chain of lakes is the introduction of northern pike. Since their introduction, pike have selectively removed native salmonids from many area lakes. They continue to impact local populations, but their condition appears to be declining possibly due to limited food supply.

Bitterroot River

Native trout populations are increasing in the Bitterroot drainage, most likely due to tighter fishing regulations. However, habitat quality continues to suffer from dewatering, introduced species and historic land use and is increasingly threatened by floodplain development, streambank stabilization and fish ponds. Most of our efforts here involve reacting to these issues, leaving little time for a focused restoration effort.

The Bitterroot fishery remains very popular and supports the highest fishing pressure per mile in western Montana.

Middle and Lower Clark Fork

Downstream of Milltown Dam, the middle Clark Fork River fishery Is dominated by rainbows and is most impacted by dams. Mainstem dams and culverts on tributaries form migration barriers that restrict spawning and recruitment. Most of the tributaries still support good populations of genetically pure resident native salmonids though they are impacted by land use activities such as mining, logging, roadbuilding and intensive agriculture. In the lower river, dam mitigation funds will be used to reduce land use and dam management impacts.

MFWP looks forward to the challenge of working with NRDP, AVISTA, the tribes, conservation districts, NRCS, landowners and community groups to assist the Clark Fork in recovering its fisheries.