Anglers of Montana that frequent the Yellowstone River should be wary of consuming their catch.

Mountain whitefish from a stretch of the Yellowstone River have been found to contain high levels of a chemical, phenanthrene. Montana Fish, Wildlife and Parks issued an advisory last week suggesting people not consume any mountain whitefish caught from Twin Bridges Road railroad bridge to Laurel.

FWP tested five mountain whitefish and five rainbow trout from the Yellowstone River after a train carrying asphalt and phosphorus derailed and collapsed a bridge into the river in June. Officials did not test any other types of fish immediately after the derailment.

What’s in the fish?

The chemical found in the fish is called phenanthrene. While it has been found to cause birth defects and reproductive problems in animals, the chemical is not known to cause these issues in humans and has not been classified as a cancer-causing substance, according to FWP’s release.

Phenanthrene actually can be found in rivers and their surrounding ecosystems, especially in the type of rock that often builds on the riverbed of the Yellowstone, FWP said.

Because of this natural occurrence, it is still unknown if the train derailment is to blame for the high levels of the chemical in the river’s whitefish.

Other chemicals in the same group as phenanthrene can be found in “oil, gas, plastics, and pesticides—and are produced through combustion of these products,” FWP’s release states.

More fish will be tested

The discovery is sparking more types of fish, including brown trout and longnose suckers, to be tested from various sites of the Yellowstone River, both above and below where the train went into the water. The tests will hopefully help FWP determine the cause of the levels and should occur this week.

“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,” FWP advises.

LOOK: Here are the states where you are most likely to hit an animal

Hitting an animal while driving is a frightening experience, and this list ranks all 50 states in order of the likelihood of such incidents happening, in addition to providing tips on how to avoid them.

More From Alt 95.7