Other Aquatic Invaders
Aquatic invasive species found in Flathead Lake:
Flowering rush
Flowering rush is a non-native aquatic plant that looks like a large sedge, and grows along lake shores and slow moving water bodies. It out-competes natives aquatic plants for space, and changes the ecosystem for fish and wildlife.
In Montana, it was recorded in Flathead Lake in 1964, and has spread. Prolific growth in irrigation ditches reduces water availability, and dense stands can impede water flow and recreational activities, such as boating, fishing and swimming.
Curlyleaf pondweed
Curlyleaf pondweed is an aquatic invasive plant that out-competes native plants for resources, like light and space, early in the growing season.
Curlyleaf pondweed commonly grows in ponds and slow moving waters. Large infestations inhibit recreation, and midsummer decay of mats can alter oxygen levels in the water.
It was first reported in Montana in Lake County in 1973. Curlyleaf pondweed is listed as abundant in Montana and widespread in many counties.
Just a few potential (of many) AIS threats to Flathead Lake:
Eurasian milfoil
Eurasian watermilfoil is a submersed aquatic plant that spreads easily on boating and fishing equipment. It grows into dense mats that prohibit swimming, boating, and fishing. Eurasian milfoil also changes the ecosystem by pushing out native plants and animals and changing water flow.
This aquatic weed is highly invasive and competes aggressively with native aquatic plant species. It is present in Montana in Noxon Reservoir, and across the state line in Idaho. Help keep it out of Flathead Lake with these simple actions.
Spiny water flea
Spiny waterfleas cause fishing rods and equipment to be clogged, preventing fish from being landed. They prey on native zooplankton, which are an important food source for native fishes. Spiny waterfleas are also not a good food source for native fishes, because their long tail and spines make them difficult to eat.
Spiny waterfleas are spread through the movement of water-related equipment. The adults and eggs can survive difficult conditions in minimal water, and the eggs can withstand freezing and drying.