National Park Staff Work to Suffocate Trout Eggs...Hopeful to Save the Native Species

The National Park Service wants to dredge Yellowstone Lake, and dump the sediment back in the lake.

They’ve asked the state of Wyoming to allow the project to move forward. They plan to use the sediment to suffocate Lake Trout eggs, to help save the native Cutthroat Trout.

All summer long, workers gill net Lake Trout from Yellowstone Lake.

They kill the non-native trout, because the big fish eat cutthroat trout.

Yellowstone cutthroats are iconic and treasured by anglers who come from around the world to catch them.

They are food to grizzly bears, eagles, osprey, and other wild animals that live here.

When Trout Unlimited volunteers helped catch and tag Lake Trout to find their spawning beds last summer, TU project manager Dave Sweet said, “This Yellowstone Cutthroat Trout Population is in severe decline. It’s being preyed upon by the Lake Trout. The population dropped from four million in this system down to about 200,000. That’s a 95% loss in this population.”

The netting operation is working. Park biologists say they’re finding fewer big Lake Trout now, and larger cutthroats. But, they’ve asked Wyoming’s Department of Environmental Quality to give State Certification to a U.S. Army Corp of Engineers permit to help them kill Lake Trout eggs and fry.

Yellowstone Public Affairs Assistant Jonathan Shafer explained, “If we can prevent the fish from reproducing, we can hopefully reduce their population in the Lake, and encourage the growth of the native population of cutthroat.”

Eric Hargett with Wyoming’s Department of Environmental Quality said the state has legal control over the water of Yellowstone Lake.

So, the Park Service asked permission to suction dredge sediment from the bottom of the lake, and drop the sediment on top of the Lake Trout spawning beds.

Hargett said the state of Wyoming issued public notices in Cody. Since the state DEQ did not receive a single comment against the proposal, the Park may have a new tool for Lake Trout control, soon.

Hargett said he expects Wyoming’s permission to come through next week. He said Yellowstone workers can start dredging sediment, and dumping it on the spawning beds right away, if they wish.

Meanwhile, this netting operation continues with the help of Yellowstone’s non-profit partner: Yellowstone Forever.

Shafer said, “And they’re contributing about a million dollars a year to the operation.”

By 2014, more than a million Lake Trout had been caught and killed.

Shafer said the netting operation killed more than 330,000 Lake Trout this year alone.