Combating Nitrogen Pollution

The Problem with Nitrogen

As every gardener knows, nitrogen is essential for the growth of living things. But an overdose of nitrogen in coastal waters can prompt harmful algae blooms that degrade coastal water quality.

Nitrogen pollution has wreaked havoc in coastal waters around the world, causing fish kills, outbreaks of shellfish poisoning, marine mammal deaths, and dead zones.

Parts of Casco Bay are now showing signs of this problem – green algae smothering mud flats, prolonged red tides, and murky waters choking out eelgrass beds. Deteriorating coastal water quality threatens our marine resources, our quality of life, and our economy.

Nitrogen Pollution in Casco Bay from Garret McAlpine on Vimeo.

Learn more: “Seeing Green?”

Stopping the Rise of Slime

Friends of Casco Bay is working to reduce the emerging threat of nitrogen pollution in Maine’s coastal waters. We are:

  • Collecting water quality data throughout Casco Bay.
  • Keeping pressure on municipalities to remove combined sewer overflows (CSOs), which mix stormwater with raw sewage. Both stormwater and sewage contain nitrogen, which can lead to nitrogen pollution.
  • Making sure large passenger ships comply with Casco Bay’s No Discharge Zone, which prohibits discharging treated and non-treated sewage into the Bay.
  • Supporting the implementation of legislation to establish nutrient standards for Maine’s coastal waters.
  • Educating our community about the spread of nitrogen pollution and what all of us can do to slow it down.


Nitrogen Resources

Learn more about the problem of nitrogen pollution – and some potential solutions – in the following articles:

Beyond Carbon: Scientists Worry about Nitrogen’s Effects, The New York Times

Reactive Nitrogen: The Next Big Pollution Problem, Wired Science

How is China Like the Coast of Maine?, excerpted from The Casco Bay Bulletin


You Can Help Stop the Rise of Slime!

Download the above “wanted” poster by clicking on the image. We are always looking for slime watchers.

In addition to making everyday decisions like driving less and avoiding the use of lawn fertilizers, you can help us fight nitrogen pollution by becoming a Slime Watcher!

Slime Watchers help Friends of Casco Bay document the extent of nitrogen pollution around Casco Bay and along Maine’s coast. Our “slime database” helps us target our efforts to stem pollution and strengthens our advocacy work.


To be a Slime Watcher:

When you’re on the Bay, keep an eye out for coves and mudflats covered in green slime. If you spot green algae, let us know at slimewatchers [at] cascobay [dot] org (tell us the location, with coordinates & landmarks, and take a photo if you can!)


Help Fund our Work to Combat Nitrogen Pollution

Support Friends of Casco Bay’s work to stop the rise of slime caused by nitrogen pollution. To donate, click here and write “nitrogen” in the designation box. Thank you for your support.