Definition

General natural community overview

Impoundments (also known as reservoirs) are artificially created standing water bodies, produced by dams on streams or rivers. Because of the diverse nature of streams, rivers, and dams, these waterbodies can vary greatly in size, configuration, flow patterns, water chemistry, and biota. Impoundments are nearly as numerous and diverse in characteristics as natural lakes, with larger and more southerly waters having the richest fish faunas. Most often the waterbodies are dominated by warmwater fishes, particularly the family Centrarchidae (sunfishes).

Rare animals

Species of Greatest Conservation Need

The following Species of Greatest Conservation Need are listed according to their level of association with the natural community type, based on the findings in the Wisconsin Wildlife Action Plan.

Please see the Wildlife Action Plan, Chapter 2.4 to learn how this information was developed.

Opportunities

Management Opportunities

The following Ecological Landscapes have the best opportunities to manage for , based on the Ecological Landscapes of Wisconsin Handbook.

Major
A major opportunity for sustaining the natural community in the Ecological Landscape exists, either because many significant occurrences of the natural community have been recorded in the landscape or major restoration activities are likely to be successful maintaining the community's composition, structure, and ecological function over a longer period of time.

Important
Although the natural community does not occur extensively or commonly in the Ecological Landscape, one to several occurrences do occur and are important in sustaining the community in the state. In some cases, important opportunities may exist because the natural community may be restricted to just one or a few Ecological Landscapes within the state and there may be a lack of opportunities elsewhere.

Present
The natural community occurs in the Ecological Landscape, but better management opportunities appear to exist in other parts of the state.

Threats / Actions

These threats and priority conservation actions were identified for the community type in Wisconsin, and they apply to all of Wisconsin's Ecological Landscapes unless otherwise indicated. Please see the Wisconsin Wildlife Action Plan, Chapter 3.3 , for more information

Threats

• Watershed and riparian land use practices and resulting non-point source pollution are leading to habitat loss and eutrophication.
• Water-level manipulations are degrading nearshore and littoral-zone habitats in some waterbodies.
• Shoreline and littoral-zone alteration and development are degrading habitat.
• Mercury bioaccumulation in fish poses a health risk to humans and other animals that eat fish, especially in waters with sediments that increase the rate of mercury methylization. Sediment characteristics appear to make impoundments more susceptible to higher rates of mercury methylization than other water body types.
• Exotic aquatic plant and animal species are degrading habitat, altering food webs, and reducing and displacing desirable native species.

Conservation actions

• Improve watershed land-use practices to reduce non-point source pollution.
• Establish water-level management regimes that more closely mimic natural water level fluctuations.
• Protect and restore shoreline and littoral-zone habitat.
• Continue to seek statewide and regional reductions in mercury emissions from key sources.
• Improve regulations and education to prevent the introduction of additional exotic species and to help control and limit the spread of existing populations.

Photos

Click to view a larger version. Please considering donating your photos to the Endangered Resources Program for educational uses. Photo use

Photos

Note: photos are provided to illustrate various examples of natural community types. A single photograph cannot represent the range of variability inherent in a given community type. Some of these photos explicitly illustrate unusual and distinctive community variants. The community photo galleries are a work in progress that we will expand and improve in the future.