HISTORY OF MACROPHYTES IN BUFFALO LAKE

From 1983 through 1991 Eurasian milfoil Myriophyllum spicatum L. was the dominant taxon from two to slightly more than four meter depths within the littoral zone of Buffalo Lake. Eurasian milfoil was occured around the perimeter of the entire lake during that period. In shallow zones the Eurasian milfoil formed an almost impenetrable mass of vegetative matter from the lake bottom, where it was rooted, to the surface.

The zone extending out from the Eurasian milfoil zone to the deepest extent of rooted plant growth was generally dominated by Elodea canadensis and Eleocharis acicularis with isolated stands of Potamogeton robbinsii Oakes, Potamogeton praelongus, and in shallower waters Chara sp.

However, since 1991 a reduction in Eurasian milfoil was observed. This led to a new study of the macrophyte population in 1995.

RESULTS OF THE 1995 STUDY OF EURASIAN MILFOIL IN BUFFALO LAKE

In July of 1995 a detailed study of the extent of both quantitative and qualitative changes in the macrophyte community of Buffalo Lake was completed. Analysis of data is still underway. However, at this point it is clear that there have been some remarkable changes in the macrophyte distribution of Buffalo lake. Eurasian milfoil, Myriophyllum spicatum, was not found in the lake. However the native milfoil, Myrioplyllum sibiricum, occurred in increased numbers from that found in earlier studies. The zone formerly occupied by Eurasian milfoil, the two to five meter zone was devoid of aquatic plants. In addition the five meter to seven meter zone formerly occupied by Elodea canadensis was devoid of plants. In other words the macrophyte zone in Buffalo lake formerly extended down to seven meters was now reduced to a zone extending slightly below two meters.

Recent studies of some Eurasian milfoil infested lakes suggest a a period of abundance lasting for about a decade, followed by a sustained decline. The Eurasian watermilfoil population in Buffalo lake appears to have declined drastically. An unusual aspect revealed by the 1995 study is that all other species below two meters have also declined. Further data analysis may provide some understanding of these changes in Buffalo Lake. These are very significant changes in the lake. However it appears that further changes in the littoral zone of Buffalo Lake will occur.

The reduction of Eurasian milfoil in Buffalo Lake could potentially enhance the lakes fishery and improve both the lakes water quality and its recreational potential. In addition it will reduce the threat of Eurasian watermilfoil infestation of other lakes in the area.

The impact of this change on the lakes biology, its recreational potential, and on the fishery needs to be examined. However further data on both the limnology and the lake fishery is needed.