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Two of the aquatic invasive species found in Idaho are Eurasian watermilfoil and zebra mussels.

Eurasian Watermilfoil

This noxious weed forms very dense mats of vegetation on the water’s surface and is transplanted by hitchhiking on vessels and motors. It has feather-like leaves arranged in whorls of four around the stem, which may reach lengths of 10 feet of more. A pink flowering spike appears above the water from June to August.

Eurasian Watermilfoil

Zebra Mussel

This tiny D-shaped mollusk can clog water intake pipes, damage vessel engines, and alter native species populations. Zebra mussels can be transported on vessel hulls, motors, and other equipment or in bilges, bait buckets, and live wells.

Zebra Mussels
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