Upper Midwest Environmental Sciences Center

Aquatic vegetation flourished in the 1930s immediately after the locks and dams were constructed to accommodate barge traffic on the Upper Mississippi River System (UMRS). The distribution of aquatic vegetation, however, has fluctuated drastically in the 1980s and 1990s. As the navigation system ages, the fate of this important ecosystem component is of growing concern.

The objectives of the project are to estimate the abundance of submersed aquatic vegetation at different reaches and to characterize its spatial distribution pattern (where it is located) and temporal dynamics (when it is located).

We collect quantitative data at randomly selected sites, where sample sizes vary among habitat types depending on acreage and heterogeneity of habitat strata. The location of sites is registered in a global positioning system with high spatial accuracy (+/- 10 m).

We quantify the status of aquatic vegetation with an abundance index calculated using point data of presence or absence and plant density rating. The data are structured for easy query as an ARC/VIEW project, which is popular among resource managers in the UMRS.

The project began in 1998 and was completed in September 2001.