Bear Lake may be suffering from invasive, harmful plants

Garden City, Utah – It’s one of Utah’s most well-known and purest lakes, yet invasive plants are threatening its purity.

A Utah State University cannabis expert is accompanying the Utah Department of Natural Resources to Bear Lake. Their target is Eurasian watermilfoil, which has been present in Bear Lake for almost four years but does not emerge to bloom.

“That means that the plant is not happy, it’s not thriving, and we don’t understand why,” said Mirella Ortiz, a weed scientist at USU.

What about the unhappy invading plant?

“A plant that’s stressed cannot absorb the herbicide and be controlled by it,” Ortiz said.

Thus, they are in the water inspecting instruments that gauge temperature and sunlight at different depths. In small marinas, they are also dragging the bottom in search of curly-leaf pondweed.

“It produces a lot of these turions, and each of these turions will sprout about 3-4 times and start new plants,” Ortiz explained.

Fish no longer have access to food or hiding places because of these invasive plants.

“They can also change the nutrient cycle of the water, and by that, they can cause harmful algal blooms at Bear Lake,” Ortiz said.

They also endanger the lives and property of people.

“If your boat prop gets stuck in these invasive plants, it gets all tangled up and then it can’t move,” explained Jessie Danninger, the DNR Bear Lake program manager. “And obviously worst-case scenario, in some of these marinas, if a kid were to fall in, they could get tangled up and they could drown.”

A tiny marina’s motorized craft was shut down by the DNR because of pondweed with curling leaves.

“Because the props will stir up all that vegetation, chop it up, and those fragments can establish new populations across the lake,” Danninger said.

Ortiz and Danninger are aware that this closure during the off-season is bad for business, but scheduling is dictated by the weeds’ growth cycle and the need to hire someone to spray.
While Utah has a plan to stop invasive mussels, according to Ortiz, with boats being examined for them, the same isn’t true for plants. Ortiz speculates that the weeds were likely introduced to the lake by a visiting boat.

“There are studies showing that plants that [stay] in the moist areas of boats during transportation, they can stay alive for up to 90 days,” Ortiz said.

“It’s a big, beautiful lake, and we want to make sure we preserve that blue, clear color,” Danninger said.