Understanding Maine's Lakes

Water Quality

Overview of Lake Water Quality - How is lake water quality measured in Maine? (VLMP)

Secchi Disk Transparency -A Secchi Disk measures water transparency (how clear the water is). This simple test can characterize lake water quality and identify changes over time. (VLMP)

Dissolved Oxygen & Temperature - An adequate supply of dissolved oxygen (DO) in lake water is essential to fish and other aquatic life forms. DO is a sensitive indicator of lake water quality (VLMP).

Phosphorus - Phosphorus is the nutrient that most influences the growth of algae in lakes. (VLMP)

Chlorophyll a - Chlorophyll a, a pigment found in algae and other plants, can be used to estimate the population of algae in a lake. (VLMP)

Color - Natural water color is important to consider when assessing water quality. (VLMP)

Specific Conductance - Monitoring conductivity can help determine if pollutants are entering a lake. (VLMP)

pH (Acidity) - Among other effects, pH helps determine which plant and animal species can live in a lake. (VLMP)

Alkalinity - Alkalinity of the lake determines the capacity of the water to buffer from changes in pH. (VLMP)

Monitoring of Water Quality

Secret Life of Data - How lake data is used. By Roy Bouchard & Linda Bacon, biologists with Maine DEP

Lake Life

Living Communities - Water on the Web

Lake Food Webs - Water on the Web


Fishing in Maine - Maine Inland Fisheries and Wildlife

Fish Species Identification - Maine Inland Fisheries and Wildlife


Maine Loon Project - Maine Audubon

Invasive Species


Maine Courtesy Boat Inspections - Overview of CBI as well as training video. (DEP)

CBI Handbook - Developed by Maine DEP, Lakes Environmental Association and Maine Congress of Lake Associations

CBI Training & Grants - Lakes Environmental Association


What to do if you find a suspicious plant? - Instructions for collecting and shipping plants to the VLMP for identification.

Invasive Plant Patrol Handbook - Training manual for volunteer Invasive Plant Patrollers, including background about invasives, plant identification techniques, screening survey procedures, documentation field sheets and more. (VLMP)

Maine DEP Invasives Program - Includes laws, reports, signs, publications, and information about the Preserve Maine Waters boat sickers. (DEP)

Maine Natural Areas Program Invasive and rare plant monitoring.

Maine's Interactive Field Guide to Aquatic Invaders - An online resource for Maine's common native and invasive aquatic plants & animals. (VLMP)

Links within the Interactive Field Guide:
Glossary of aquatic plant terms
Plant ID Key

Invasive Fish - Maine Department of Inland Fisheries & Wildlife

Other Invasives - Including fish, algae, crayfish, snails, wetland plants, and other flora and fauna. (VLMP)

What You Should Know About Maine's Invasive Plant Patrol - Presentation for use by Maine’s lake and watershed associations to spread awareness of invasive aquatic plants and volunteer opportunities to join in the effort to protect our lakes and ponds. (VLMP)


Battling the Invaders - Summary of control methods, networking for control groups and case studies (VLMP)


Lake & Watershed Connections - By Scott Williams, Maine VLMP

Watershed Overview - Water on the Web

Watershed Academy - Training and resources for watershed management.

Conservation Practices

Camp Roads Comprehensive information about camp roads and resources for maintenance (Maine DEP)

Camp Roads An introduction by Maine DEP Biologist and Lake Education Coordinator Barb Welch (VLMP)


Maine Volunteer Lake Monitoring Program