Introduction

Lake Washington in Washington State is where many people call home. It surrounds the city of Mercer Island and is bordered by several others including Seattle, Bellevue, Renton, and Kirkland:

Map view of Lake Washington and surrounding area

Ground view of Lake Washington

For over 100 years people have lived along its shores. The lake is a source of beauty, fun, and relaxation for many residents of the greater Seattle area. In the 1950's the lake was heavily polluted, concerned citizens were able to divert the pollution and restore Lake Washington back to health by 1975. Whether we like it or not, Seattle residents are stuck with the lake and maintaining its health is beneficial to all of us. (kingcounty.gov)





While we have gotten pollution under control in the past, Lake Washington still has a pest known as Myriophyllum spicatum or Eurasian Water Milfoil. An invasive aquatic plant that spread across the world, it has become an inhabitant of over 100 lakes and rivers in Washington.

Eurasian Water Milfoil

 It can adversely affect biotic factors by creating dense mats that are unsuitable for fish and invertebrates by changing the chemistry of the water, interfering with water circulation, out-competing native plants, and increasing the rate of lake sedimentation. Eurasian watermilfoil can also interfere with human activities by clogging boat's engines, tangling up fishing lines, and getting caught on swimmers. (invasivespeciesinfo.gov)