Vegetation Monitoring and Assessment Protocol Manual

Preface

Over the past decade, a number of invasive aquatic plants have become established in New York State. Eurasian watermilfoil (Myriophyllum spicatum), Curly-leaf pondweed (Potamogeton crispus) and Waterchestnut (Trapa natans) have caused interference with water-based recreation through the State. These and several other exotic macrophytes out compete low-growing native species. If much of the macrophyte biomass is within a meter of the surface, swimming, boating and fishing can be seriously impaired along large tracts of shoreline.

At present there are many "low technologies" available to limit the spread of these nuisance plants. However, an effective management program consists of a thoughtful and integrated approach, which uses a selection of physical, chemical and biological control technologies. The program should be designed and optimized to ensure that the ranges of techniques will indeed reduce use impairment to acceptable levels, while at the same time be cost-effective and free of unintended negative environmental impacts.

Although a lay person may believe that "all aquatic plants are the same", a nuisance plant management program has to be tailored to both the target species and the environmental setting. The ecological growth requirements of the target plant will almost always determine the appropriate techniques to use. Thus, it is important to have good information on the extent and composition of the aquatic plant communities in an impaired lake, in order to adequately design a management program. This protocol manual for aquatic plant sampling and data analysis was prepared to guide the development of such a program.

Although the need for such a protocol manual has existed for some time, the catalyst for preparation of an actual manuscript was a proposal made by John Madsen and Jay Bloomfield to the Finger Lakes Association Water Resources Board (WRB). The Finger Lakes region is located in central New York State (Figure 1) and by our definition consists of the nineteen counties that are represented on the WRB. The WRB, through grants from the New York State Department of Environmental Conservation (NYSDEC) and additional funds provided by member counties, conducts a program of nuisance aquatic vegetation control on the eleven Finger Lakes and a number of smaller waterbodies with public access. The WRB provided funds to develop this protocol manual.

Figure 1

After the outline of the manual was developed, major topics on vegetation quantification were assigned to a nationally recognized expert in the fields of aquatic botany and nuisance plant management. Dr. C. Barre Hellquist of Massachusetts, who recently co-edited the new edition of the Fassett's Manual of Aquatic Botany (Crow and Hellquist, 1991), was assigned the task of describing how a lake manager should proceed in the identification of aquatic plants. Dr. John Titus of New York prepared information on how to use the line-transect method to quantify bottom coverage of selected species. Dr. John Madsen of Texas described the methods used for estimating aquatic plant biomass. Dr. David Spencer of California discussed how to conduct the statistical analysis of aquatic plant data. Mr. Alan Cibuzar of Minnesota prepared information on the use of remote sensing of aquatic plant communities. Dr. Peter Newroth described his experiences in developing an aquatic plant management program for the Province of British Columbia. Each expert presented their information at the Tenth Annual Meeting of the North American Lake Management Society, which was held in November, 1990. Subsequently, each prepared a manuscript that will be published in the Journal of Lake and Reservoir Management (see References). These six articles constitute a critical companion document to this manual.

This document is the final report to the Finger Lakes Association Water Resources Board for the project to establish guidelines for quantifying aquatic vegetation in conjunction with nuisance plant management programs throughout the Finger Lakes Region. Funding for preparation of this manual was provided by the Finger Lakes Association Water Resources Board and the New York State Department of Environmental Conservation through grants to the Natural Heritage Trust (NHT) and the Rensselaer Polytechnic Institute Fresh Water Institute (RFWI). The authors would like to thank the FLA/WRB for supporting this effort, Mr. Robert Brower, Mr. Bruce Gilman and Mr. Kevin Moss for reviewing drafts of the manuscript and the participants in the NALMS workshop for their assistance.

Introduction

Why quantify vegetation? Even if individuals have considered monitoring aquatic plants in conjunction with a management program, most of them consider that "visual inspection" is sufficient to "know what is going on." However, quantification is important for several reasons:

1. Quantification involves objective measurements of plant distribution and abundance, rather than subjective estimates or judgments. Relying on the latter can lead to opinion, rather than fact, as the basis for management decisions.

2. Quantification allows rigorous statistical and mathematical evaluation of plant community trends or assessments of the effectiveness of management tactics.

3. Quantification as part of a monitoring program may save money through eliminating costly but unproductive tactics or reductions in the amount of costly chemicals or techniques.

4. Quantification allows individuals other than the observer to establish trends in plant abundance or distribution.

5. Quantification as part of a monitoring and assessment program is being required by many granting or permitting agencies as part of or a prelude to issuing grants or permits.

This report attempts to provide concrete recommendations on aquatic vegetation quantification as part of an overall plant management program. The report is divided into an overview of methods, development of an Integrated Management Plan, and recommendations for minimal and best monitoring practices. The purpose of this report is to provide guidelines for developing a quantitatively based monitoring and assessment program as part of an overall aquatic plant management program, rather than prescribing what should be done.

The amount and coverage of aquatic plants can have a significant effect on the recreational access, quality of fisheries and overall aesthetic appeal of a lake. Fishermen, swimmers, boaters and lake shore dwellers are concerned about aquatic vegetation when the plants become dense enough to interfere with human usage of the lake surface. To the average person, all plants are alike and are often referred to as "weeds, seaweeds or waterweeds". However, since each species of aquatic plant has different growth requirements, an understanding of the composition of the aquatic plant community is critical to the preparation of a nuisance vegetation control program. Extensive vegetation surveys are expensive and require the expertise of an aquatic botanist. It is thus important to design such surveys in a judicious manner, such that the information needed to manage the aquatic plant problem is neither inadequate, inappropriate nor excessive.

The process of surveillance consists of the following steps:

1. Consultation with and retention of a qualified aquatic botanist. A practical knowledge of aquatic plant magagement techniques is helpful but not a requirement.

2. Find out what types of plants are present. The first step is to determine what species of aquatic plants are in the lake. Individual voucher specimens of each species should be collected, identified and saved for later reference. This step is quite inexpensive, but requires careful attention to detail. The results should be summarized in table-form listing the Latin and common names of each species, where they were located, whether they were rare, common or abundant and whether the plants were submerged, floating or emergent. Other information on general location, plant height and presence of flowers and fruits may also be noted.

3. Prepare a vegetation map of the lake. The second step is to prepare a qualitative map of the predominant and/or nuisance species of aquatic plants (Figure 2), from Kishbaugh, Bloomfield and Saltman, 1990). If aquatic plant problems are not that widespread, maps of individual bays and coves may suffice. The map should be based on an accurate base map, either the bathymetric map of the lake, or an outline map traced from a United States Geological Survey (USGS) 7½° topographic map. The actual densities or biomass of the individual species need not be shown on this map. The map can be base on a field survey of transects observed by SCUBA divers. The complexity of the field survey can be reduced by the parallel use of aerial photography. Computerized remote sensing, such as described by Cibuzar (1992), could be used as a substitute technique. The use of remote sensing will be quite costly for a small lake macrophyte survey.

4. Establish permanent bottom coverage transects and biomass sampling locations. In order to judge the effectiveness of future control techniques, baseline sampling stations for percent bottom cover and biomass should be established. The exact methods are described by Titus (1992) and Madsen (1992).

5. Conduct an effective and thorough analysis of all data. All information should be tabulated, checked for errors and entered into a computer. Mapping and statistical software should be used to analyze patterns and trends in the data. Spencer (1992) gives an account of some of the simple statistical techniques that can be applied to aquatic plant survey data.

6. Continue sampling plant populations over time to establish the presence or absence of trends. Aquatic plant communities are highly influenced by both human activities and long-term weather conditions. A well designed sampling program will detect such trends, usually before they become apparent to the casual observer. The long-term monitoring program will conclusively establish the effectiveness of the vegetation management program. Newroth (1992) gives an excellent account of the monitoring effort associated with the British Columbia vegetation control experience.

If these steps are followed, there will be sufficient information to design, implement, optimize and measure the success of a comprehensive aquatic plant management program. If these steps are not followed, the program may be poorly designed, ineffective and unnecessarily expensive. Worse, though, if the program flounders and private citizens complain that the lake is "still full of weeds", there will be no defensible information as to why the management program failed. Often a poorly contrived and unsuccessful program is worse than no action at all.


Appendix--Organizations and Contact Persons

North American Lake Management Society, Inc.
One Progress Boulevard
Box 27
Alachua, FL 32615-9536
(904) 462-2554
ATTN: Ms. Lorraine Duncan

New York State Department of Environmental Conservation
Lake Services Section
Bureau of Technical Services and Research
50 Wolf Road - Room 301
Albany, NY 12233-3502
(518) 457-7470
ATTN: Dr. Jay Bloomfield

New York State Department of Environmental Conservation
Citizen Statewide Lake Assessment Program
Lake Services Section

Bureau of Technical Services and Research
50 Wolf Road - Room 301
Albany, NY 12233-3502
(518) 457-7470
ATTN: Mr. Scott Kishbaugh

Rensselaer Fresh Water Institute
MRC 203
Rensselaer Polytechnic Institute
Troy, NY 12180-3590
(518) 276-6757
ATTN: Dr. Charles Boylen, Director

Aquatic Nuisance Control Program
State of Vermont
Agency of Natural Resources
Vermont Department of Environmental Conservation
103 S. Main Street, BLD. 10 North
Waterbury, VT 05676

(802) 244-5638
ATTN: Ms. Holly Crosson

U.S. Army Engineers
Waterways Experiment Station
Environmental Laboratory
Environmental Assessment Division
3909 Halls Ferry Road
Vicksburg, MS 39180-6199
(601) 634-2606
ATTN: R. Michael Stewart
CEWES-EN-A

Upstate Freshwater Institute
110 Hillsborough Parkway
Box 506
Syracuse, NY 13214
(315) 446-7301
ATTN: Dr. Steven Effler

New York Federation of Lake Associations, Inc.
Waterworks
2175 Ten Eyck Avenue
Cazenovia, NY 13035
(315) 655-4760
ATTN: Ms. Anne Saltman

References

Anderson, M.R. and J. Kalff. 1986. Regulation of submerged aquatic plant distribution in a uniform area of weedbed. Journal of Ecology 74:953-961.

Boyd, W.A. and R.M. Stewart. 1990. Preliminary simulation results of triploid white amur stocking rates for Guntersville Reservoir using AMUR/STOCK (Version 1.5). pp. 247-260. In: Proceedings, 24th Annual Meeting, Aquatic Plant Control Research Program, Miscellaneous Paper A-90-3, US Army Engineer Waterways Experiment Station, Vicksburg, MS.

Cibuzar, A. 1992. Remote Sensing. In: Madsen, J.D. and J.A. Bloomfield (Eds.). Aquatic Vegetation Quantification for Lake Management. Lake and Reservoir Management, In press.

Clesceri, L.S., A.E. Greenberg, and R.R. Trussell, eds. 1989. Standard methods for the examination of water and wastewater, 17th Edition. American Public Health Association, Washington, DC.

Clifford, P.A., J.H. Rodgers, Jr. and R.M. Stewart. 1990. Comparison of HERBICIDE simulation results with field measurements. pp. 261-270. In: Proceedings, 24th Annual Meeting, Aquatic Plant Control Research Program, Miscellaneous Paper A-90-3, US Army Engineer Waterways Experiment Station, Vicksburg, MS.

Cooke, G.D, E.B. Welch, S.A. Peterson and P.R. Newroth. 1986. Lake and Reservoir Restoration. Butterworth Publishers, Stoneham, MA. 392 pp.

Crow G.E. and C.B. Hellquist. 1991. Fassett's Manual of Aquatic Plants, Third Edition. University of Wisconsin Press., Madison, WI.

Eichler, L.W. 1990. Assessment of Brant Lake. Rensselaer Fresh Water Institute Report #90-17, Rensselaer Polytechnic Institute, Troy, NY.

Hellquist, C.B. 1992. Taxonomic considerations in aquatic vegetation assessments. In: Madsen, J.D. and J.A. Bloomfield (Eds.). Aquatic Vegetation Quantification for Lake Management. Lake and Reservoir Management, In press.

Kishbaugh, S.A., J.A. Bloomfield and A. Saltman. 1990. Diet for a Small Lake, A New Yorker's Guide to Lake Management. New York State Department of Environmental Conservation and Federation of Lake Associations, Cazenovia, NY. 189 pp. + App..

Lawrence, L.R. and H. Lemmon. 1990. Feasibility of using expert systems in aquatic plant control. Technical Report A-90-8, US Army Engineer Waterways Experiment Station, Vicksburg, MS.

Madsen, J.D. 1992. Biomass techniques for monitoring and assessing control of aquatic vegetation. In: Madsen, J.D. and J.A. Bloomfield (Eds.). Aquatic Vegetation Quantification for Lake Management. Lake and Reservoir Management, In press.

Madsen, J.D., M.S. Adams and P. Ruffier. 1988a. Harvest as a control for Potamogeton pectinatus in Badfish Creek, Wisconsin: Frequency, efficiency, and its impact on the stream community oxygen metabolism. Journal of Aquatic Plant Management 26:20-25.

Madsen, J.D. and J.A. Bloomfield (Eds.). 1992. Aquatic Vegetation Quantification for Lake Management. Lake and Reservoir Management, In press.

Madsen, J.D., L.W. Eichler and C.W. Boylen. 1988b. Vegetative spread of Eurasian watermilfoil in Lake George, New York. Journal of Aquatic Plant Management 26:47-50.

Madsen, J.D., J.W. Sutherland, J.A. Bloomfield, L.W. Eichler and C.W. Boylen. 1991. The decline of native vegetation under dense Eurasian watermilfoil canopies. Journal of Aquatic Plant Management, 29:94-99.

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Nichols, S.A. 1974. Mechanical and habitat manipulation for aquatic plant management. Wisconsin Department of Natural Resources Technical Bulletin 77, Madison, WI. 34 pp.

Stewart, R.M. 1990. Simulation technology development: An overview. pp. 237-239. In: Proceedings, 24th Annual Meeting, Aquatic Plant Control Research Program, Miscellaneous Paper A-90-3, US Army Engineer Waterways Experiment Station, Vicksburg, MS.

Spencer, D.F. 1992. Using the experimental approach to answer questions relating to the quantification of aquatic vegetation. In: Madsen, J.D. and J.A. Bloomfield (Eds.). Aquatic Vegetation Quantification for Lake Management. Lake and Reservoir Management , In press.

Titus, J.E. 1992. Distribution of aquatic plants within lakes: Line transect methods. In: Madsen, J.D. and J.A. Bloomfield (Eds.). Aquatic Vegetation Quantification for Lake Management. Lake and Reservoir Management, In press.

Titus, J., R.A. Goldstein, M.S. Adams, J.B. Mankin, R.V. O'Neill, P.R. Weiler, Jr., H.H. Shugart, and R.S. Booth. 1975. A production model for Myriophyllum spicatum L. Ecology 56:1129-1138.

United States Environmental Protection Agency. 1990. The Lake and Reservoir Restoration Guidance Manual, Second Edition. North American Lake Management Society, Washington, DC. 326 pp.

Westerdahl, H.E. and K.D. Getsinger, eds. 1988. Aquatic plant identification and herbicide use guide; Vol. II: Aquatic Plants and susceptibility to herbicides, Technical Report A 88-9, US Army Engineer Waterways Experiment Station, Vicksburg, MS.

Westlake, D.F. and F.H. Dawson. 1982. Thirty years of weed cutting on a chalk stream. Proceedings EWRS 6th Symposium on Aquatic Weeds 6:132-140.

Wooten, J.W. 1990. Plant growth simulation models for Hydrilla and Eurasian watermilfoil. pp. 240-246. In: Proceedings, 24th Annual Meeting, Aquatic Plant Control Research Program, Miscellaneous Paper A-90-3, US Army Engineer Waterways Experiment Station, Vicksburg, MS.