Maine’s inland waters are in trouble as ongoing drought conditions and increasingly warmer summers create better conditions for toxic algae blooms.
The worst may be yet to come, according to a state water quality expert.
“In general this year is worse than ever before with more reports of algal blooms than in previous years,” said Laura Bacon, lake assessment section leader with the Maine Department of Environmental Protection.
All Maine lakes and ponds contain algae — small plant-like organisms. Under normal conditions, they are a beneficial part of a freshwater ecosystem. It’s when an algae population explodes in size and numbers — or blooms — that it creates problems.
As conditions in Maine become warmer, the number of lakes and ponds experiencing blooms is expected to increase and intensify. These blooms can limit recreation — coming into direct contact with an algae bloom while swimming, for example, can cause skin or eye irritation — and also pose serious health risks to those who live on or frequent affected waters. Swallowing an algae bloom can cause nausea, headaches, diarrhea, vomiting and even liver damage, while dogs have died after drinking algae-laden water.
Every year, according to Bacon, Maine is already seeing more blooms due in large part to climate change. Algae blooms occur due to a combination of warming temperatures, increased nutrients and a reduction in water movement.
“Conditions are becoming optimum in many of our lakes for algae to proliferate,” Bacon said. “These days there are high amounts of the nutrients they need plus higher temperatures.”
There are certain lakes or ponds in Maine that are expected to get blooms each year. This year, Bacon said some water bodies are seeing blooms for the first time, including Moose Pond in Mount Vernon, Little Pennesseewassee in Norway and Adams Pond in West Newfield.
Up in Aroostook County, Cross Lake is producing heavy algae blooms near the shoreline.
Bacon is even seeing a new species of algae in several lakes, which she said is an indicator of just how bad things are getting.
“A species of planktothrix showed up in Damariscotta Lake in 2020 in high concentrations,” she said. “That was the first time I had ever seen that.”
Since then, the species has shown up in five other lakes.
The appearance of more and new algae corresponds with a rise in lake surface water temperatures, according to Bacon.
“There has been a significant change in the temperatures in the top warm layers of water,” she said. “Those layers can be 12 or 15 feet deep and they are much warmer than 20 years ago.”
At that time, Bacon said, the average late summer temperature in that layer was 75 degrees. Now it’s common to see 81 degrees.
This is the time of year when Maine lakes are at their most stressed, according to Bacon.
“Now is when they are at their warmest and when they get the most nutrients accumulating at the bottom,” she said. “When you get enough of the right kind of nutrients accumulating in the sediment, you don’t get any oxygen released into the water [and] that is happening in a number of our lakes.”
Blooms can be mitigated, Bacon said, by adding aluminum to the water. They can also be controlled or even prevented by proper management. But that management has to evolve with climate change, she said.
“Rainfall can carry nutrients and sediment into the lakes that can contribute to blooms,” Bacon said. “But the rainfall patterns we use now to deal with blooms are from many years ago [and] if we continue to manage based on previous data and conditions have changed, it will manifest in the algae.”
Climate change needs to be part of the freshwater management plant, Bacon said.
“People need to know what is going on with the lakes and ponds,” she said. “There is so much attention paid to the ocean and coastal areas and not nearly as much to inland waters.”
She’d also like to see more financial resources placed on protecting inland water quality in the state.
“For years scientists have been predicting a lot more algae blooms in our latitudes as a result of climate change and I don’t doubt it is happening,” Bacon said. “Our lakes are really suffering now and I really don’t see it getting any better.”
Anyone who suspects there is a bloom in a Maine lake or pond is urged to report it to the DEP using their online form.
