Aquatic HerbicidesExamples of usage for control of aquatic weeds

in other bodies of water around the west

Sierra Ecosystem Associateswww.sierraecos.com

Tahoe Keys Property Owners Association is developing a comprehensive management plan to control invasive aquatic weeds in the Keys lagoons, and is studying herbicides as one of several control methods.

The following slides show the safe, successful use of herbicides in other water bodies in the western U.S. Combined with the isolation of the Tahoe Keys lagoons from Lake Tahoe, CA and Federal EPA approved herbicides could effectively be used in the Keys.

The following examples also demonstrate the safety of herbicide use for both people and native species.

For further information on the locations of previous herbicide use, contact Sierra Ecosystem Associates.

Introduction

Sacramento-San Joaquin Delta + Discovery Bay

Weeds: Water hyacinth, egeria densa, curlyleaf pond weed, spongeplant

Control methods: herbicides, herding, mechanical harvesting

Results: Program started in 2014-15 to gain control over 3,000 acres of weeds

Impact: Proven safe for public water systems and multiple ESA-listed threatened and endangered fish and wildlife

California Division of Boating & Waterways

Big Bear Lake, California

Weeds: Eurasian watermilfoil and curlyleaf pond weed

Control methods: herbicides, mechanical harvesting

Results: Weeds reduced from 1,000 acres to 94 acres since 2000

Big Bear Municipal Water District

Clear Lake, California

Weeds: Hydrilla, Eurasian watermilfoil

Control methods: Herbicides, mechanical harvesting, dredging and grass carp

The presence and vigor of hydrilla decreased in 2009, and infestation increase was halted in 2012

California Department of Food & Agriculture

Loomis Lake, Washington

Weeds: Eurasian watermilfoil, egeria densa

Control methods: Herbicides, SCUBA diver hand pulling

Results: egeria decreased from 59 percent to 8 percent, Eurasian watermilfoil reduced from 82 percent to 13 percent

Washington Department of Fish & Wildlife