Clear As a Lake: a Resource Guide to Invasive Aquatic Plants and Non
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Clear As A Lake A Resource Guide to Invasive Aquatic Plants and Non-Toxic Treatment Alternatives 1 Acknowledgements Toxics Action Center would like to thank all our members for their generous support of our work to cleanup and prevent pollution in New England and especially for supporting the publication of this resource guide. This project is funded in part by the Massachusetts Environmental Trust. We would also like to thank the citizen activists who advocate tirelessly every day to make their communities safe and healthy places to live. Our special thanks go to Anna Stressenger, Kelsey Robertson, and Meghan Moda, Toxics Action Center summer interns who helped research and compile this report. At Toxics Action Center, we believe that everyone has the right to breathe clean air, drink clean water and live in a healthy community. For 21 years, Toxics Action Center has assisted residents and community groups across New England to address toxic pollution issues. For more information about Toxics Action Center, please contact our offices at the number below or online at www.toxicsaction.org. Eastern Massachusetts Office New Hampshire Office 44 Winter Street, 4th floor 30 S. Main Street, Suite 301-B Boston, MA 02108 Concord, NH 03301 Phone: (617) 292-4821 Phone: (603) 229-1331 Fax: (617) 292-8057 Fax: (603) 229-3221 Western Massachusetts Office Rhode Island Office 233 N. Pleasant Street, Suite 32 9 South Angell Street, 2nd Floor Amherst, MA 01002 Providence, RI 02906 Phone: (413) 253-4458 Phone: (401) 421-0007 Fax: (413) 256-6435 Fax: (401) 331-5266 Maine Office Vermont Office 39 Exchange Street, Suite 301 141 Main St., Suite 6 Portland, Maine 04101 Montpelier, VT 05602 Phone: (207) 871-1810 Phone: (802) 223-4099 Fax: (207) 253-1966 Fax: (802) 223-6855 Connecticut Office 198 Park Road, 2nd floor West Hartford, CT 06119 Phone: (860) 233-7623 Fax: (860) 223-7574 Meredith Small & Sylvia Broude, Authors Toxics Action Center June 2008 For additional copies of this report, send $10 to the Boston, Massachusetts office listed above. © Copyright 2008 1 Table of Contents Executive Summary……………………………………………………………….. 4 Recommendations………………………………………………………………… 5 Chapter I: Introduction to the Problem of Invasives……………………………… 6 Chapter II: Commonly Found Invasive Species…………………………………… 8 Eurasian Watermilfoil………………………………………………………. 8 Curly-Leaf Pondweed……………………………………………………… 8 Fanwort…………………………………………………………………….. 9 Hydrilla……………………………………………………………………...9 Phragmites………………………………………………………………... 10 Purple Loosestrife………………………………………………………… 10 South American Waterweed………………………………………………. 11 Water Chestnuts…………………………………………………………... 12 Chapter III: Commonly Used Aquatic Herbicides………………………………... 13 Notable Moments in Pesticide History……………………………………. 14 2,4-D……………………………………………………………………… 15 Copper……………………………………………………………………. 15 Diquat Bromide……………………………………………………………16 Endothall………………………………………………………………….. 17 Fluridone………………………………………………………………….. 17 Glyphosate………………………………………………………………... 18 Chapter IV: Alternatives to Aquatic Herbicides………………………………….. 20 Artificial Aeration / Circulation…………………………………………… 21 Barley Straw………………………………………………………………. 21 Benthic Barriers…………………………………………………………… 22 Draw-downs………………………………………………………………. 23 Dredging………………………………………………………………….. 24 Dyes………………………………………………………………………. 24 A Case Study: Lake Cochituate in Natick, Massachusetts……………………….. 26 Hand Harvesting………………………………………………………….. 28 Herbivorous Fish………………………………………………………….. 28 Herbivorous Insects………………………………………………………. 29 Hydroraking………………………………………………………………. 30 Management of Nutrient Input…………………………………………… 31 2 Mechanical Harvesting……………………………………………………. 32 Rotovation…………………………………………………………………32 Selective Plantings………………………………………………………… 33 Surface Covers…………………………………………………………….. 34 Appendix A: Further Resources for Management of Aquatic Invasive Species…... 35 Appendix B: Lake Cochituate Case Study Materials……………………………… 36 Year 1 Budget Estimates for Integrated Vegetation Management Plan at Lake Cochituate…………………………………………….. 36 Letter from the Natick Board of Health to the Natick Conservation Commission………………………………………………………... 37 Letter from the Natick Selectboard to the Natick Conservation Commission………………………………………………………... 39 Testimony from a plant biologist regarding the proposal to use aquatic herbicides………………………………………………. 41 Letter from the Conservation Law Foundation to the Massachusetts Department of Conservation and Recreation’s Stewardship Council……………………………………………………………... 43 Letter from a University of Massachusetts Professor of Geosciences to the Natick Board of Health and the Natick Conservation Commission………………………………………………………... 44 Appendix C: Rutland Herald news article regarding aquatic herbicides…………... 45 Endnotes………………………………………………………………………… 48 3 Executive Summary Lakes and ponds are complex systems that provide a home for many species of plants and animals. They also provide humans with a place to relax, play, and enjoy nature. When invasive plants are introduced to lakes and ponds, they can drastically change the characteristics of these complex aquatic systems. Invasive aquatic plants are a serious problem and can take over an entire lake and make it unusable, not only by other plants and animals, but also by humans. Control of invasive aquatic plants is most common via waterborne pesticides or herbicides. In Massachusetts alone approximately 230 water bodies are commercially treated with herbicides each year in an attempt to reduce or control invasive plants or other aquatic weeds. We now know that these toxic chemicals can be linked to a wide range of public health and environmental concerns. They can be dangerous to other plants, animals, and most importantly human health. Potentially more troubling is the vast amount that we still do not know about pesticides and their impact on people - especially children - and our environment. This resource guide provides a basic explanation of the aquatic invasive plant problem currently facing many lakes and ponds across the United States. Included are eight profiles of invasive aquatic plants commonly found in the Northeastern United States. This guide also provides information about the environmental and human health risks connected with the chemical treatment of invasive plants. Included is information on the six chemicals that serve as the main active ingredients in aquatic herbicides and 15 alternative treatment techniques that can be used to reduce or control invasive aquatic weed problems. The guide also contains a case study on Lake Cochituate in Natick, MA where state and town officials have launched a pilot project to manage invasive aquatic weeds using non-toxic techniques. Finally, the manual provides a list of resources available to concerned citizens interested in learning more about managing invasive plants in lakes and ponds across the region. 4 Recommendations Protect your Lake or Pond using Preventative Measures The best way to control invasive aquatic plants is to stop the invasion before it starts. In order to prevent invasive aquatic plants, the plant must first be identified at the source of infiltration, such as along the bottom of a boat, and then stopped from entering the lake or other water body. This strategy involves public education, constant monitoring and rapid action. If you are a boat owner, be sure to thoroughly clean your boat, trailer, fishing gear and any other items that travel from water body to water body. If you have an aquarium, never dump its contents into lakes, ponds, drainage ditches or down street drains – some aquarium plants are invasive species. Dispose of all invasive or exotic plant species properly – in a dry area, away from water bodies and in an appropriate receptacle such as a compost bin. Manage Invasive Species by Using Non-Toxic Methods of Control Once a body of water is infested with an invasive plant, a combination of eradication and suppression techniques can be employed. Communities can implement invasive plant control strategies that consider the area to be managed and select the correct mix of tools to reduce the population of invasive weed and maintain it at the lowest level possible. Eradication of aquatic invasive plants is difficult if not impossible. Communities should instead seek to manage invasive plant growth using methods that minimize adverse impacts on native species, water quality, and public health. Recent lack of federal leadership to strengthen pesticide-use laws and regulations means that much of the work to reduce toxic pesticide exposures falls on states and local communities. An effective way for communities to keep their environment and their population healthy is to learn from and engage other towns that have had success, or are considering using non-toxic methods of invasive aquatic species control. The decision for lake management begins at the local level, at town Conservation Commissions. Phasing Out Persistent Toxic Chemicals Every year, the United States Environmental Protection Agency (EPA) reviews an average of 1,700 new chemical compounds. The 1976 Toxic Substances Control Act requires that these compounds be tested for any ill effects before approval only if evidence of potential harm exists. Frequently, this evidence is not yet available for new chemicals, which leads to the approval of about 90 percent of new chemicals without restriction. Only a quarter of the approximately more than 82,000 chemicals used in the U.S. have been tested for toxicity.1 We are seeing chemicals take their toll on our health, as illnesses continue