Eurasian milfoil is an exotic plant that was introduced to the lower Great Lakes from Europe in the early 1970s (Aiken et al. 1979); it has since become a major component of the Long Point submerged plant community (Figure 5.3), particularly along the north shore (Table 5.2).
Its distribution increased substantially between 1976 and the early 1990s, followed by a decrease in distribution and abundance by 1995 (Table 5.3). It presently forms dense monotypic stands in the deepest part of the Inner Bay, while it is much less abundant in areas that are less than 0.5 m deep. Milfoil has a profound effect on native macrophytes as it forms a thick surface layer that shades out other species (Madsen et al. 1991). It is tolerant of a wide range of temperatures, and typically thrives in environments such as Long Point. For instance it grows best in turbid, eutrophic environments, that have sandy or sandy loam substrates, particularly where water is between 1 and 4 m deep. Extensive growth has resulted in displacement of submerged plants in other wetlands (Carpenter 1980) and this may well have been, and could continue to be, the case at Long Point. This should be of major concern, as Eurasian milfoil has a fairly low nutritive value for waterfowl (Martin and Uhler 1935) and it is underutilized by foraging waterfowl at Long Point, given its wide distribution (see section 5.3).
