NewsMontana News


Anglers advised to avoid eating Mountain Whitefish from portion of Yellowstone River

Posted at 11:56 AM, Aug 14, 2023

(Montana Fish, Wildlife and Parks Press Release)

BILLINGS - The Fish Consumption Advisory Board, consisting of representatives from Montana Department of Public Health & Human Services (DPHHS), Montana Department of Environmental Quality (DEQ), and Montana Fish, Wildlife & Parks (FWP), has issued an initial consumption advisory on all mountain whitefish caught in the Yellowstone River from Twin Bridges Road railroad bridge to Laurel. Further testing is needed to determine the contamination source and long-term guidance. The board may update the initial consumption advisory as more information is gathered.

As part of a follow-up to the train derailment that occurred on June 24, FWP staff collected five mountain whitefish and five rainbow trout of various lengths below the derailment site for contaminant testing. Results from the mountain whitefish tests showed levels of a chemical called phenanthrene high enough to warrant an advisory to avoid all consumption of mountain whitefish. It is not yet known if the impacts to mountain whitefish are a result of the train derailment. Rainbow trout collected in this area did not show any levels of contamination. No other species of fish, including brown trout, were collected for testing.

Additional fisheries testing will be conducted in the area later this week. FWP plans to target additional mountain whitefish and rainbow trout, brown trout, shorthead redhorse, longnose suckers, and white suckers as available. Fish will be collected above and below the derailment site. Those with specific concerns may want to avoid consuming any species of fish from the Yellowstone River in the area until more is known on the severity and prevalence of this contamination. The agencies will alert the public as soon as this information is available.

Phenanthrene is within a group of chemicals called polycyclic aromatic hydrocarbons, or PAHs. The specific source of this chemical present in the mountain whitefish is currently unknown, as some PAHs occur naturally in the environment, especially in the shale rock common in the Yellowstone River Basin. PAHs are also found in products such as oil, gas, plastics, and pesticides—and are produced through combustion of these products. Laboratory tests on animals have shown exposure to PAHs can cause birth defects, reproductive problems, and damages to skin, body fluids, and immune systems. These effects from eating fish with high levels of PAHs have not been recorded in humans.

The U.S. Environmental Protection Agency and the International Agency for Research on Cancer have not classified phenanthrene as a cancer-causing substance because there is not enough information on this specific chemical. However, exposure to other PAHs has been shown to cause cancer in laboratory animals and in people who work for many years around mixtures of PAHs.

For more information on PAHS and phenanthrene, visit: