Lakes
We coordinate toxic algae and invasive-plant monitoring in Washington lakes and sample fish and sediments from some lakes each year to test for toxic metals and other chemicals. We curate a large database of information on lakes and offer other resources to support efforts to monitor and improve lake health.
Lake plant problems
We assist those who need to manage invasive plants in lakes and rivers. Aquatic invasive plants are a serious threat to the health of Washington’s lakes, rivers, and streams. Our Lakes Environmental database keeps information on plants that have been found in many Washington lakes in the past.
- Washington State Toxic Algae is a partnership website that contains data and information on toxic algae in Washington lakes, including latest lab results.
- Aquatic weed control technical assistance provides advice on identifying, monitoring, and managing invasive freshwater aquatic plants.
- Aquatic invasive plant management grants fund technical assistance, public education, and grants to help control aquatic invasive plants.
- Aquatic pesticide permits are almost always needed for treatments that use chemical products in or near water.
Recent and historical lakes information
Currently, most lake water quality monitoring is conducted by counties, local health departments, lake associations, and volunteer groups. We support these groups with information and technical assistance. We participate in EPA's National Lakes Assessment every five years. The most recent survey was in 2022.
We coordinated a large lake-monitoring program in the 90's. We tested for dissolved oxygen, water clarity, temperature, and contaminants. While this program is no longer funded, we maintain the data.
Lakes Environmental Data
We store and share lake data from across the state. These data include historical monitoring and current sampling results from our scientists, as well as data compiled under local-government projects we fund. The information includes some photographs and lake-bottom maps (bathymetry).
Look up a lake here: Lakes Environmental Data.
Toxics in lakes
We test sediment cores from three lakes annually for persistent chemical trends. These chemicals include lead, mercury, and organic contaminants, such as PAHs, depending on the year of the study. We also test mercury in freshwater fish from 28 lakes across the state on a rotating schedule and resample every five years to see if mercury is going up or down in the fish. As of 2025, we test PFAS in the fish tissue, as well.
Contact information
Wes Glisson (he/him)
Aquatic plant specialist
wes.glisson@ecy.wa.gov