Temperatures rising in Flathead Lake

Flathead Lake is remarkably clean this year but could possibly get warmer than ever this summer, Yellow Bay Biological Station Director Jack Stanford said during his State of the Lake address at the recent annual Flathead Lakers meeting.

Stanford said the lake is in a “very delicate balance” related to nutrient loading from nitrogen and phosphorus, and it doesn’t take much for the bays or the entire lake to turn green with algae.

Stanford said he believes the lake will reach the highest temperatures ever recorded this summer, and temperature is key to creating conditions in which algae can thrive.

Yet water clarity remains good this year, he said.

Research data shows there is no trend in primary productivity, or the lake’s ability to grow algae, but nitrogen levels in the lake are increasing, which could spell problems for the future.

Stanford also discussed his concern about the potential for another “trophic cascade,” a profound change in the lake’s food web. The last occurred after mysis shrimp reached the lake in 1981, causing a dramatic increase in lake trout numbers with adverse effects on native bull trout and a kokanee fishery that no longer exists.

“The very worst thing that could happen now is to get some other alien species in the lake,” Stanford said. “I’m really worried about two mussel species, which would cause another trophic cascade.”

Quagga and zebra mussels also were a topic for another speaker at the meeting, former Glacier National Park Superintendent Chas Cartwright.

An accidental introduction of the mussels, which have caused severe damage in waters outside Montana, “would be a game-changer,” Cartwright said.

There has been a multi-agency effort to prevent that from happening through watercraft inspections and education, and Cartwright said he believes prevention is possible.

Also at the meeting, the Flathead Lakers presented its 2013 Stewardship Award to the Nature Conservancy and the Nature Conservancy of Canada for raising $10 million needed to cover the costs of withdrawing mineral rights in the Canadian North Fork.

The money allowed the British Columbia provincial government to reimburse companies that had incurred exploration expenses prior to the province banning mineral extraction in the drainage.

Richard Jeo, the conservancy’s Montana director, and Nancy Newhouse, representing the Nature Conservancy of Canada, accepted the award.