Eurasian Watermilfoil

Description

Eurasian watermilfoil is a submersed perennial that roots in the bottom sediments and regrows from root crowns. The stem is generally branched and can grow to 15 feet or more. The stem is round with whorls of usually four featherlike leaves, most often with 12 to 24 finely dissected segments per side. The elongated flowering spikes rise about 2 to 4 inches above the water. Dispersed fragments of this plant can spread the species rapidly. It produces viable seeds but they rarely germinate to produce mature plants.

Habitat

Eurasian watermilfoil is a non-native species introduced from Europe, Asia and northern Africa. It was introduced into the United States about 1942 and has since spread to at least 38 states and Canada. Eurasian watermilfoil occurs in dense colonies in several Tennessee Valley reservoirs. It frequently displaces native species and often restricts recreational use in shallow bays and along shoreline areas. Algae, duckweed and mosquito fern are frequently found floating on the surface of milfoil mats. Watermilfoil provides habitat and food for several fish and waterfowl species and other aquatic organisms. 

Identifying Features

What It Looks Like—Eurasian watermilfoil is easily identified by its feathery leaf appearance. Leaves, in sets of four, are whorled around the stem of the plant. Each leaf has up to 12 pairs of leaflets, giving the plant its featherlike appearance.

Where to Find It—Eurasian watermilfoil was once the Tennessee River system’s most abundant and well-known plant. In recent years, hydrilla and eelgrass have begun to dominate traditional areas of milfoil. However, milfoil can still be found throughout many reservoirs in the system.

Max Depth—0 to 15 feet

Similar Species—Eurasian watermilfoil may appear similar to cabomba and coontail; however, Eurasian watermilfoil has a whorled leaf orientation, unlike the opposing-leaf arrangement of cabomba.

Seasonal Fishing Techniques

Spring—A classic target for many anglers, Eurasian watermilfoil will be one of the first plants to sprout and grow from existing structures in the early part of spring. Find the deep-water edge where this plant often grows and work a Carolina rig or big jig around clumps of newly growing plants.

Summer—This species is often one of the first to begin topping out. Much like hydrilla, the open understory beneath is a prime place for bass seeking shelter on a sunny day. Get out your favorite creature bait and flip the holes in its canopy. Go heavy on line (braid or heavy Fluro)—you’ll need it.

Fall—Eurasian watermilfoil will begin to exhibit some browning, even in late summer. But the plants will persist well though the fall. Milfoil is the perfect opportunity for frog fishing as the canopy will easily hold up the bait, but the understory is open enough for a bass to key in on the target.

Winter—While growth may have stopped and fragmentation begun, Eurasian watermilfoil will maintain some of its leaves and stems throughout the winter months. When other grass is gone, find those clumps of milfoil in 10+ feet of water. Fish low and slow for those fish staging before the spring spawn.

Drawbacks

Eurasian watermilfoil was traditionally one of the most problematic weeds in the Tennessee Valley region. In recent years, it has been mostly replaced by hydrilla and eelgrass. However, milfoil continues to cause problems in some TVA reservoirs.