Do long-term macrophyte management efforts in inland lakes effect system wide biotic richness and diversity?

Lake Moraine (42 50’ 47” N, 75 31’ 39” W), in Madison County in east-central New York State, is an artificially raised impoundment originally formed by the damming of a valley by the deposition of glacial moraine. This 106 ha (261acre) water body comprises two distinct basins separated by Madison County Rt. 87 traversing a causeway between them. A submerged culvert under the highway joins the north and south basins. The northern basin occupies 32 ha (79 acres), has a maximum depth of about 3.7 m (12 feet) and a mean depth of 1.l m (3.7 feet). This study, and most human activity, focuses upon the southern basin which occupies 74 ha (182 acres), has a maximum depth of 13.7 m (45 feet) and a mean depth of 5.4 m (17.7 feet) (Harman et al. 2003). The lake is dimictic and eutrophic, as reflected by low transparency, high productivity of algae and vascular plants and hypolimnetic oxygen depletion during summer stratification. Phosphorus appears to be limiting (Harman 1978; Oglesby 1975). Agricultural activities and residential development are believed to be primarily responsible for the bulk of the phosphorus loading (Hohenstein et al. 1997). Excessive algal and submergent macrophyte growth, primarily Eurasian water milfoil, has chronically impaired recreational activities (Anon 1991; Harman et al. 1997).