Glacier National Park Officials Want to Put Rat Poison in Lake: Here’s Why

by Emily Morgan
Photo by: HaizhanZheng

There’s no doubt that Glacier National Park is a fisherman’s paradise. Every year, millions visit the national park to fish the lakes. The lakes are home to over 20 species of fish, including six kinds of trout. In addition, since it’s on federal land, no license is required for anglers.

Now, the NPS hopes to transform one of Glacier National Park’s lakes into a trout refuge. In addition, park officials are taking a different approach by using rat poison as a tool.

To create a safe environment for these fish, the agency first needs to eliminate the non-native trout in the lake.

The park’s plan, if approved, would start in September of next year. It recommends using a long-used pesticide and rat poison called rotenone.

Although it’s a naturally derived compound, it has been banned from using on rodents since 2005. However, it’s still a widely used fish toxin or piscicide.

Like many lakes in the Western part of the country, Gunsight Lake was historically fishless. However, in the early 1900s, this lake was artificially stocked with rainbow trout to create recreational fishing opportunities.

Since then, the rainbow trout created a self-sustaining population in the lake. Via hybridization, the fish now threaten the existence of native cutthroat trout within the same Saint Mary’s waterways.

Officials in Glacier National Park now hope to implement the fish toxicant via an inflatable boat and backpack sprayers with helicopters to help establish their population.

To limit contamination of the Saint Mary River, officials will also use a neutralizing agent, potassium permanganate, downstream. When the non-native fish are removed, the park stocks the river with cutthroat trout.

Glacier National Park officials get pushback over plan for poisoning non-native fish

While this method may seem uncommon, it’s definitely not. For instance, in the Grand Canyon, the park service plans to use similar techniques to save native fish species.

While many support the tactic at the Grand Canyon, some argue the NPS should consider an alternative in Glacier National Park.

Margaret Townsend, an attorney for the Center for Biological Diversity, wants the park to consider alternatives.

“Because poison is indiscriminate. It’d just kill everything in the lake. We’d prefer other options be explored in a situation like this one,” she said.

Townsend suggested the idea of electrofishing, a method that uses electricity to harvest unwanted fish. Another option, according to Townsend, is hosting a fishing derby.

This would be a contest that lets anglers to catch as many fish as possible. She also suggested a hybrid model, perhaps one which utilizes electrofishing, then tracking to ensure all fish are caught.