How do I report an algal bloom?

Every year alga blooms occur on a few lakes in Maine. The warmer water temperatures and long sunny days are conducive for algae to grow. These blooms can be very intense, changing the entire lake to a bright green color. As the algae die, blue-green colored scum’s (floating clumps of algae) can form with odors being present. There are 54 lakes in Maine that frequently support algal blooms. If you see a very noticeable discoloration develop in the water and it’s not the common yellowish layers of pine pollen in early summer, please give the DEP a call.

Call (207) 287-3901 or (800) 452-1942 in-state. Ask to speak to the "on-call" person in the Division of Environmental Assessment.

When reporting a potential algal bloom, try to get on the lake and look around in several places, including the deeper areas. Try to answer the following questions. It is not necessary to have answers to all these questions in order to report a bloom.

  1. Name of the lake and town.
  2. Name, address, phone number of person reporting.
  3. When did this start? How long has the condition persisted?
  4. Is the bloom mixed in the water or is it attached to plants, rocks or other structures? If it is attached, describe the size and color of the growths. Are they stringy or jelly–like or like cotton candy?
  5. If mixed in the water, what were the color(s) of the water and how intense were they?
  6. Is the water turbid (cloudy) or is it full of particles you can see with the eye?
  7. Was the bloom concentrated in certain areas (especially in downwind coves) or was it throughout the lake?
  8. Is there an obvious odor? (describe)
  9. Is there a surface scum?
  10. Have you seen anything like this (or heard similar reports in this or another year?)
  11. If you are a volunteer monitor, what was your most recent Secchi reading for the lake (and the date)?

If you are interested in monitoring your lake, contact the Maine Volunteer Lake Monitoring Program at (207) 783-7733. You can also visit the Lakes of Maine website for more lakes information and data.