CHAPTER 1 - A Citizen's Manual for Developing Integrated Aquatic Vegetation Management Plans

INTRODUCTION

Does Your Water Body Have An Aquatic Plant Or An Algae Problem?

This manual specifically deals with controlling nuisance aquatic plants. To use this manual, it is critical to distinguish between aquatic plant problems and water quality problems associated with excess algae production (see box).

Managing aquatic plant problems should follow the integrated aquatic vegetation planning route described by this manual. More specifically, integrated aquatic vegetation management plans focus on controlling aquatic plants, which flourish (often to nuisance levels) on enriched sediments in suitable habitats.

Algae and other water quality problems should follow the lake restoration planning approach. Lake restoration plans deal with correcting water quality problems whose symptoms are seen in water chemistry and algae production.

 Aquatic Plants and Algae

Aquatic plants are large vascular plants that live in wet conditions. Aquatic plants (also called macrophytes) usually possess true roots, stems and leaves, and look like plants in your yard. They can be grouped into four types: emergent plants, rooted floating-leafed plants, submersed plants, and free-floating plants. Emergent plants have a large portion of stems and leaves growing above (emerging from) the water surface; they are found in shallow water (less than 2 feet deep) or along the shoreline. Rooted floating-leafed plants have leaves that float on or just above the surface but are connected to the bottom by long, tough stalks. Submersed plants have most of their leaves and stems below the water surface, often with flowering parts projecting above surface. They may be securely or loosely rooted in the bottom. Free-floating plants float near the water surface with root systems dangling in the water, but not connected to the sediment.

Algae are simple, primitive plants that do not have true roots, stems or leaves. Many algal species are microscopic forms that float in the water (called phytoplankton). Some appear as large, easily seen upright forms, and are called macro-algae. Certain types of green algae can form stringy colonies 3 feet or more in length. Nuisance algal growth commonly associated with nutrient problems often appears in the form of surface scums that are greenish or brownish in color.

What Is An Integrated Aquatic Vegetation Management Plan?

Designing a cost-effective and environmentally sound aquatic plant management program is a challenge. Aquatic plant communities vary greatly from one body of water to the next. Likewise, the human uses of each lake, pond or river are unique, as are the activities along its shore. Furthermore, a range of aquatic-plant control methods (physical, mechanical, chemical, biological) are available. These can vary widely in cost, effectiveness and environmental impacts. The critical issue facing those who hope to remedy an aquatic plant problem is selecting methods that are appropriate for the water body.

Mapping a course of action can be made easier by careful development of an integrated aquatic vegetation management plan (Plan). The Plan provides a means to make informed decisions for managing aquatic plants that protect human health and the environment. It also assures that aquatic plant management is consistent with other management plans affecting the water body, such as watershed management or shoreline management addressed in local or county master plans.

Development of a Plan uses an approach based on integrated management of land plants that considers such concerns as:

• How bad is the aquatic plant problem?
• At what level will plants become harmful and when should action be taken to control them?
• When is the best time of year to kill, remove, or suppress the nuisance plant species?
• What methods will best deal with the target species, and for how long?
• How will the treatment affect humans, native plants and wildlife?
• Are the costs reasonable and affordable?

When Is A Plan Required?

The State of Washington strongly encourages development of long-term, integrated aquatic plant management strategies to deal with nuisance aquatic plants in lakes, ponds, or rivers. Work spent identifying alternatives early on will save time and money later down the line.

Plans may be required before certain aquatic plant control activities may be initiated. For example, the Aquatic Weeds management Fund calls for completion of a Plan before projects can be considered for implementation grants (see Appendix E).

Also, the Environmental Impact Statement for Ecology's "Aquatic Plant Management Program" recommends that a plan be prepared before certain permits are issued for use of herbicides. More and more local governments are requiring aquatic plant management plans that are consistent with local policies and regulations.

Balancing Act: Consideration of these and other site-specific factors is necessary when choosing management methods for a specific water body. There is no magic bullet. For example, no method exists that can completely remove an exotic species infestation and at the same time be inexpensive and have no effect on the local ecology.

Thus, the planning process should carefully balance all these concerns to develop a plan that meets the needs of the community while preserving the health of the ecosystem.

Living Document: The Plan should be flexible and allow for change. Creating a living document provides for modification of the plan in response to new information of changing circumstances. Factors that could affect the Plan include changes in the aquatic plant problem, water use priorities, and land uses. Also, plant control technologies as well as government policies and regulation may evolve over time and affect the Plan.

Taking the Long View: Aquatic plant management is a long-term venture; achieving management goals for a water body can take many years. Even after main goals are attained, some form of management, if only minimal, may be necessary to maintain aquatic plant conditions.

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