CHAPTER 9 - A Citizen's Manual for Developing Integrated Aquatic Vegetation Management Plans

CHARACTERIZE AQUATIC PLANTS (STEP G) 

Once you have mapped the aquatic plants in your water body, the next step is to use that information to write a description of beneficial and problem plant zones. Characterizing the aquatic plant zones allows you to determine where special control actions are required. Step G consists of the following tasks:

1. Describe Plant Types
2. Determine Problem Areas and Beneficial Plant Zones
3. Determine Need for Special Action

1. Describe general plant types: The purpose of this task is to write a description of the main types of aquatic plants occurring in the water body. Give the general locations of plant beds and the maximum depth of growth. Also estimate how much of the surface area is occupied by plants.

Problem plant areas: Identify what parts of the water body are affected by the following problems:

• The presence of invasive exotic species
• Excessive native plant growth that interferes with such important water body uses as swimming or boating.

Beneficial plant zones: Identify conservation areas, fish rearing habitat or native vegetation considered beneficial to fish, waterfowl, and other wildlife currently utilizing the water body. In addition, locate endangered, rare or sensitive plant zones. The highest priority is given to preserving these plant communities. Their presence may also limit use of certain aquatic plant control methods in and near the water body.

3. Determine special need for action in water body The presence of any non-native, invasive aquatic plant species signals an urgent situation. Because of the nuisance potential posed by these invaders, immediate action is necessary. Special funding is available for new infestations of non-native species through Ecology's Aquatic Weeds Management Fund.

 Example Of Written Description Characterizing Aquatic Plants

A description of the aquatic plants in Lake Tranquil might read like this: "Aquatic plant growth in this lake is confined to a narrow band around most of the shoreline, extending out to 12 feet in depth. The total area of the lake occupied by aquatic plants is estimated to be about 40 acres (or 40% of the entire lake area). Some isolated patches of emergent, plants such as iris, cattails, and other reeds and rushes occur along the shoreline. A large water lily bed occupies the end of the lake where the swim beach is located. The submersed plant community is composed of sparse stands of naiad, common elodea and small-leaf pondweed in the shallows, and moderately-dense beds of big-leaf pondweed occurring throughout the deeper water areas. A large, surfacing stand of milfoil also occurs near the boat launch. In addition, a few scattered stands of milfoil plants are present at the opposite end of the lake (near the swim beach), intermingled with the other submersed plants.

The entire bay with the boat launch as well as the near-shore region at the opposite end of the lake are highest priority problem zones because of the presence of the exotic weed milfoil. These milfoil areas require special control action. Another problem zone is the swim beach area which is heavily populated with water lilies; these surfacing beds make shoreline access as well as actual swimming most difficult and dangerous.

Lake Tranquil supports a planted trout fishery and nesting blue herons, and the native beds of pondweed, elodea, and naiad form an important source of food and refuge for these and other aquatic wildlife. Also, the wetland stands near the swim beach are classified as a conservation area, and are recognized as beneficial zones and protected as part of the overall aquatic-plant management plan."

In completing the planning steps to this point, you may have uncovered new and critical information on the nature and type of aquatic weed problems in your water body. This new information may affect some of your initial objectives. For instance, you may have discovered the existence of exotic plants or sensitive plants in your water body. These conditions will affect your choice of management goals and control options. If this information wasn't available to you as you started the planning process, it may be necessary to revisit STEP A and STEP B and refine the Problem Statement and Management Goals. Once the necessary revisions are made, they should be presented to the larger community for approval through the public process. Now it is time to look at available control options.

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Questions about this page?
Contact Kathy Hamel by e-mail at kham461@ecy.wa.gov