The State of Montana Fish Guidance Board, which includes Montana Fish, Wildlife and Parks (FWP), Department of Environmental Equality (DEQ), and Public Health and Human Services (DPHHS), has released an updated fish consumption advisory, recommending the public avoid consuming all species of fish from the Clark Fork River below Missoula. In response to new research results, all species of fish have been deemed unfit for safe consumption due to the high level of pollutants found within the tissue of fish caught in the river. “We are asking people to avoid consuming fish that have been caught from the Clark Fork River’s confluence with the Bitterroot down to the Flathead,” Trevor Selch, FWP Fisheries Pollution Biologist, said.

A press release issued by FWP on December 18 states the advisory has expanded to include all fish species, for a 148-mile stretch of the Clark Fork River’s confluence with the Bitterroot River, just west of Missoula, to the confluence of the Flathead River, near Paradise. The new data that was collected was used to assess chemical contaminants including dioxins, furans, and polychlorinated biphenyls (PCBs) found in fish tissue in a study done on the Clark Fork that extended from approximately 30 miles upstream of Missoula to 100 miles downstream. Selch also said samples have been taken up the Bitterroot. While the press release states the source of all contaminants found in the fish have not been attributed, testing in the area is underway as part of water quality monitoring around the former Smurfit-Stone site.

The current fish consumption advisory has been expanded from a 2013 warning that advised people to avoid eating pike, and to limit the consumption of rainbow trout that have been caught in the Clark Fork River downstream of the former Smurfit-Stone mill site. Previous data which was taken from a rainbow trout caught in St. Regis shows the sample, at the time, had the highest level of contaminants that had been found in the river. Upon further review of the studies, new guidance was issued based on those high levels of contaminants.

In 2013, when the initial samples were taken, the Environmental Protection Agency (EPA) listed the Smurfit-Stone mill as a future superfund site. The mill was listed as a clean-up site in 2010, when Smurfit-Stone declared bankruptcy and permanently shut down the facility. This site is currently listed as being in a Remedial Investigation and Risk Assessment phase of the superfund remedial process. “It’s expensive to run these tests,” Selch stated. "The tests that were recently run in 2018 and 2019, that was all funded by the EPA.” Selch says the EPA has no future plans to continue testing fish in the Clark Fork River belowParadise. “The EPA is more focused upstream, and those sites like Missoula,” Selch said. Selch noted that while it seems logical to test further downstream, he doesn’t know what the EPA’s plan is for the future.

As far as fish consumption in Sanders County goes, Selch says people should proceed with caution. “We’ve been pushing for years to get samples further down the stream, but it’s a tough call,” he said. “We don’t have any sampling in that area, so we have no info going further down the stream.” Selch said if people are in the sensitive consumer group (including women of child-bearing age and children under the age of 7), consumption of the pollutants at high levels can lead to neurological and developmental problems. They shouldn’t be eating any fish species caught in the tested areas of the Clark Fork River. Ultimately, Selch says if someone is concerned, it’s best to avoid consumption. “When you are at an ‘avoid’ level of consumption, even with a meal guidance plan and only eating fish from the river once a month, if you are concerned, just avoid consumption completely.”

The study only looked at contaminant concentrations found in the muscle tissues of northern pike and rainbow trout. FWP says the same “avoid” guidance is extended to all species present in the Clark Fork River near Missoula. According to FWP, brown trout, whitefish, small- and large-mouth bass, northern pikeminnow and sucker species should all be avoided as they all have similar food habits, habitat use and lifespan, which suggests they could also contain chemical concentrations at potentially dangerous levels.

The state agencies say at high levels of exposure, the contaminants found in the fish have been linked to adverse human health effects in the immune and nervous systems and may be associated with birth defects. Dioxins and PCBs are definite and probable human carcinogens, with prolonged exposure.

For more information about the human health effects of eating fish, contact DPHHS at (406) 417-9848. For information about fish advisories on the Clark Fork River and throughout Montana, contact FWP at (406) 444-5686, or visit FWP’s website at fwp.mt.gov. Click “FishMT,” then “Fish Consumption Guidelines.”