LIVINGSTON — If you’ve been to Sacajawea Park in Livingston recently, you may have noticed an alarming sight—dozens of dead fish lining the lagoon's edge. But according to Montana Fish, Wildlife and Parks (FWP), it’s actually quite common.

"This was an environmental issue that occurs in many bodies of water across the state," says Morgan Jacobsen, information and education manager for FWP Region 3.

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He tells me that FWP believes the large fish kill to be a result of dissolved oxygen in the lagoon.

"So, what happens when a small water body like this freezes over in the winter, that ice essentially caps the oxygen that’s in the water body until the ice melts off," Jacobsen says.

He says small water bodies like the Sacajawea Lagoon have a limited oxygen level already—causing reduced oxygen during winter to become deadly for the fish.

"Especially when you have organic matter or vegetation in the water already—they use up oxygen as well," he says.

Jacobsen explains that most of the fish that winter in the lagoon occur there naturally, like carp and brown trout, that make their way in from Fleshman Creek nearby.

"But the pond is usually stocked in June with rainbow trout for the most part," he says.

As for the dozens of fish killed by the lagoon's low winter oxygen level, Jacobsen says they will simply return to the ecosystem.

"Wildlife live and die naturally in lots of places, so they don’t necessarily pose a significant environmental concern there," he says.

So, despite the concerning sight, the dead fish don’t represent any sort of issue with the health of local hatcheries.

"This is a phenomenon that we see almost every year in various water bodies throughout the state, but especially if they’re smaller water bodies like this," says Jacobsen.