|Some of Our Most INFAMOUS Aquatic Invasive Plants Zebra Mussel: A menace in the Great Lakes, river systems and some large lakes. First discovered in 1988, the shelled menaces filter and eat phytoplankton (microscopic plants), small zooplankton (microscopic animals), and detritus (pieces of organic debris) that are important to native food webs. Quagga Mussel: The smaller Quagga Mussel is equally as harmful to freshwater environments. It, too, disrupts food webs by foraging on phytoplankton, zooplankton, detritus. They were first found in 1989 and native to Ukraine.Purple Loosestrife: Although the blooms are attractive, they’re destroyers down below. Purple Loosestrife displaces native shoreline plants like cattails. Their invasion dates to the early 1800’s when the destructive plant was brought to North America for its ornamental appeal.Eurasian Milfoil: One of the most pervasive invasives in North America, Eurasian Milfoil is common in Europe and Asia. But in our waters, it quickly smothers native plants and clogs surfaces with a sometimes-impenetrable canopy. Eurasian Milfoil has been here for decades.Water Hyacinth: The floating plant and its flowers are attractive in koi ponds, but let loose, Water Hyacinth spread like wildfire, quickly overtaking surfaces, and snuffing sunlight for native plants. The dastardly Asian plant has been in North America since the late 1800’s.Giant Salvinia: Yet another aggressively growing surface plant that blocks sunlight, crowds out native species, and reduces oxygen levels. Discovered in the 1990’s, the harmful plant is presently making its way across Texas.