The Submerged Aquatics of University Bay: A Study in Eutrophication

Marked changes in quantitative composition have occurred since 1922, with the most marked difference being the great increase in Myriophyllum exalbescens and the complete disappearance of several species that were formerly major components of the vegetation.

Abstract

The submerged aquatic plants of University Bay, Lake Mendota, Dane Co., Wisconsin, were sampled using the line intercept method. Twenty-one lines, perpendicular to the shoreline and extending into the bay to the depth at which growth of submerged aquatic plants ceased were sampled. All plants intercepting the line were recorded within consecutive half-meter segments of the line. The data were used to construct a contour map of the vegetated portions of the bay and to delimit the plant communities. Six plant communities were found. Data on plant height and standing crop were obtained from quadrat samples taken at biweekly intervals from four regions within the bay. The data were compared with studies made in 1922. Marked changes in quantitative composition have occurred since 1922, with the most marked difference being the great increase in Myriophyllum exalbescens and the complete disappearance of several species that were formerly major components of the vegetation.