The Confederated Salish and Kootenai Tribes are advising all tribal members to avoid consuming all species and sizes of fish harvested from the lower Clark Fork River from the Bitterroot River near Missoula to the Flathead River near Paradise.

Recent testing has confirmed the presence of polychlorinated biphenyls (PCBs), dioxins and furans in fish at levels that are unsafe for consumption by tribal peoples, according to a press release sent Tuesday.

“This is a precaution rooted in science and our responsibility to protect tribal health and well-being. We urge our people to stay informed and make safe choices,” said Tom McDonald, CSKT Council vice-chair.

Tribal officials also advise members to avoid consuming rainbow trout and northern pike harvested from the Bitterroot River and the upper Clark Fork River above the Bitterroot River to Rock Creek, and to avoid consuming rainbow trout from the Blackfoot River.

The press release said that PCBs, dioxins, and furans build up in fish tissue over time through water, sediment and the aquatic food web. These contaminants pose a health risk to all fish consumers, and an even greater health risk to the most sensitive members of the tribal population including women of child bearing age, pregnant nursing women and young children. 

These contaminants have been linked to negative health effects in the immune, and nervous systems and may be associated with birth defects. Dietary exposure to PCBs is linked to development problems in children whose mothers were exposed to PCBs before becoming pregnant. PCBs and dioxins are classified as probable and definite human carcinogens, respectively. Dietary practices are the most important source of exposure to PCBs, dioxins and furans.

CSKT said it is aware that avoiding the consumption of fish from these waterbodies reduces opportunities for tribal members exercising off-reservation fishing rights. The tribes will continue to work to maintain the rivers and fisheries within CSKT aboriginal territory where they are healthy, and restore the rivers and fisheries where they are harmed.

This advisory is indefinite and will remain in place until further notice.