Study reveals pesticides in Glacier lakes

By CHRIS PETERSON - Hungry Horse News

In the summer of 2005, a group of scientists took a camping trip of sorts in Glacier National Park. They visited two well-known Park lakes. Old Man Lake, on the east side, and Snyder Lake on the west side.

But this was no ordinary camping trip. They also brought along tons of scientific gear to study the water, fish, sediment, lichen and pine needles around those lakes as well.

By all rights, you couldn't put a group of smart men and women in a more pristine place. Unfortunately, what they found in the fish and the snow and the sediment and the lichen and the pine needles wasn't pristine at all.

It was a litany of chemicals and pesticides, some of which were at such high levels that they could potentially be toxic to the critters that ate them.

Such were the preliminary results of the Western Airborne Contaminants Assessment Project as presented by Dixon Landers, the Environmental Protection Agency Scientist that headed up the effort.

The project sampled eight western parks, including Glacier. In Glacier, Snyder and Old Man Lakes were chosen because they were high mountain lakes that weren't fed by glaciers.

The study team didn't want glacier-fed lakes because glaciers, by their very design, can store and hold chemical contaminants in their ice for decades.

In this case, scientists wanted to see what they would find in the here and now, so to speak.

What they found was that pesticides — in particular — seem to be pervasive in the lakes. Some pesticides are still in use, but others have been banned for decades.

Yet they still show up in Glacier's watersheds and fish.

"We found significant correlation's of agricultural land near Parks and (pesticide) compounds in Parks," Landers noted.

Glacier, of all the parks in the west, actually has the most agricultural land surrounding it in a 150-kilometer radius — about 23 percent, according to figures provided by Landers. It also showed the highest pesticide levels.

Even banned pesticides are still showing up in the Park, decades later. For example, Chlordane, a popular pesticide for ants and termites, among other bugs, was banned in the U.S. in 1988.

Yet Glacier, of all the Parks, had the highest concentrations. Pesticides and other semi volatile organic compounds, like PCBs, can be released when a farmer simply plows his field. PCBs, for example, were widely used as a coolant and lubricant before they were discovered to cause cancer. Yet they persist in the environment because they simply don't break down very easily.

So even Glacier's harsh, cold winters and hot, dry summers have no effects.

In addition, some pesticides, while they are banned in the states are still perfectly legal in Canada.

The compounds also tend to "bioaccumulate" in animals like fish. They might be in tiny, tiny amounts in say, a freshwater shrimp, but then a cutthroat trout, in even its short life, will eat thousands of shrimp.

Compounds like PCBs then accumulate in the fish's liver, forming abnormal growths. It also can mess up the reproductive system of the fish. For example, about 10 percent of the male cutthroat trout in Glacier that were caught in the study had a pre-vitellogenic oocyte. In short, they were beginning to grow egg cells — a decidedly female trait.

Some fish had compound concentrations that were so high that animals that normally eat fish, like belted kingfisher, mink and otters, could be potentially harmed by the compounds.

Which begs the question: Should humans eat the fish?

Landers said that wasn't his call to make. He's fielded similar questions at other parks, including a park where backcountry rangers ate the fish all summer long.

But the data is what it is, he noted.

And in Glacier's case, the lakes aren't proving to be as pristine as one could have possibly imagined.