Winter Fish Kill ‘Event’ Found on Several Western Montana Lakes
Replenishing is underway in some instances, but you still hate to see this happen. Such is an example of this harsh Montana winter we just experienced.
Montana Fish, Wildlife and Parks tells us that several Blackfoot Valley lakes experienced a "winterkill event" this year, losing a portion of their fish populations. Smaller, shallow lakes are particularly vulnerable.
Montana FWP explained that fish kills occur when prolonged ice cover and snow reduce oxygen levels in the water. If oxygen falls low enough for a long enough period of time, fish can die. Biologists have been surveying the extent of the impact of this year’s long winter on fish populations. Here are some western Montana lakes they have found to be affected so far, and some of the actions being taken.
Upsata Lake: Experienced a severe winterkill event this year, losing a large portion of its fish including largemouth bass, northern pike and yellow perch. Biologists will evaluate the status of fishery in upcoming weeks before determining management actions.
Browns Lake: Biologists observed several hundred dead rainbow trout of various sizes. However, many live fish (spawners) were observed along shoreline, and anglers are already catching non-spawners in deeper water. Browns Lake will be re-stocked with fingerling rainbow trout on its normal schedule in June and September.
Harpers Lake (pictured): Approximately 80 large rainbow trout (retired brood stock) died over the winter, with limited mortality of other fish in the lake. Re-stocking of lake with catchable rainbow trout and westslope cutthroat trout has already begun and will continue this spring.
Fortunately, no unusual winter kill mortality has been observed on other area lakes and ponds, including Beavertail Pond, Frenchtown Pond and larger lakes in the Seeley Lake area. If you happen to notice any unusual fish kills on your next excursion, you are asked to contact your nearest FWP office.