Which invasive milfoil type can significantly disturb recreational activities such as boating?

The invasive milfoil type that can significantly disturb recreational activities such as boating is Variable milfoil. This species, scientifically known as Myriophyllum heterophyllum, has a growth pattern that can lead to dense mats forming on the water's surface. These dense mats create significant obstacles for boating, swimming, and other water activities, as they can hinder access, reduce water quality, and impact fish populations. The growth of variable milfoil can also lead to increased sedimentation and changes in water chemistry, further affecting the ecosystem and recreational use of the waterbody.

While other types of milfoil, such as Eurasian and hybrid, also cause ecological concerns and can affect recreational activities, variable milfoil is particularly noted for its vigorous growth and ability to thrive in various water conditions, making it a formidable obstacle for lake users.