Home » A Changing Casco Bay report

Tag: A Changing Casco Bay report

Shop local food

What can you do to help the Bay this summer?

Shop local food
Buy local food at your local farmer’s market.

Hooray! It’s officially summer! We are finally getting outside—in our own backyards, on road trips, and on or near Casco Bay. We have a few easy actions you can take to protect our coastal waters while you savor summer.

  • Buy fresh food from local farmers. Buying local reduces gasoline used for the transportation of goods and services.
  • You’re doing even more for Casco Bay if you grow your own veggies.
  • Walk or bike more places. It’s good for you and for Casco Bay.
  • Check the pressure of your car tires. Cars use less gasoline when the tires are properly inflated and engines are tuned up.
  • Don’t put fertilizers on your lawn. Your lawn likely doesn’t need them—and neither does the Bay. Nitrogen-laden fertilizers lead to algae blooms in our coves and nearshore waters.
  • Pick up pet poop.

Want more ideas for ways to help the Bay? Check out our list of 60 suggestions: https://cascobay.org/you-can-make-a-difference-in-the-health-of-casco-bay. (This is a section of our report A Changing Casco Bay.)

Photo by Kevin Morris

Friends comment on Friends’ A Changing Casco Bay report


When Friends of Casco Bay released the report, A Changing Casco Bay, on April 28, we heard from the Environmental Protection Agency—and that was a good thing!

Melville P. Coté, Jr., Acting Chief, Surface Water Branch, EPA, Region 1, commented, “EPA is proud to count Friends of Casco Bay among its key partners in the fight for clean water. We rely on organizations like this to educate the public about how they can be better stewards of the environment and to engage citizen scientists to collect data that help inform better management of our coastal waters.”

Matthew Liebman, also with EPA’s New England Branch, said, “This report highlights several important issues that EPA has worked on with Friends of Casco Bay since its founding in 1989, especially nutrient pollution and coastal acidification. Staff scientists and our old friend Joe Payne have rigorously documented that nutrients, especially nitrogen, is enriched in certain small estuaries within Casco Bay.

“We are especially appreciative of the leadership that Friends of Casco Bay has taken on establishing the connection of coastal acidification to effects on shellfish populations in Casco Bay. Its work is also important nationally, since Casco Bay and the Gulf of Maine have been recognized by both NOAA and EPA as a ‘hot spot’ for effects of coastal acidification.”

Going forward, EPA plans to use the report for future collaboration. Coté said, “The findings of A Changing Casco Bay are particularly timely, as they will help inform efforts by the Casco Bay Estuary Partnership to update the 2006 Casco Bay Plan.” Liebmann added, “We are pleased that the Friends are partners in helping EPA and the Casco Bay Estuary Partnership install sensors in South Portland to help monitor coastal acidification in Casco Bay.”

You can read A Changing Casco Bay on our website at cascobay.org/a-changing-casco-bay.

If you would like to receive a print copy, email us at keeper [at] cascobay [dot] org and include your mailing address and phone number.

Did you see the news? “A new report reveals the answer to “How healthy is Casco Bay?”

Read A Changing Casco Bay online The full report is posted on this page. If you would like to receive a print copy, email us at keeper [at] cascobay [dot] org and include your mailing address.

The chemistry of the water in Casco Bay is changing more rapidly than anyone could have predicted. Nitrogen from fertilizers, sewage, and air pollution accounts for much of the acidification of our coastal waters.

Our research on clam flats has found a disturbing link between acidic mud and clam flats where it is no longer profitable for clammers to harvest shellfish.

Jennifer Fox and Rick Frantz, owners of Andy’s Old Port Pub on Portland’s waterfront and residents of Great Diamond Island, spoke at the press conference. They commented, “People from ‘away’ remark on how clear the water is in Casco Bay. But you can’t see the nitrogen.”

You can read what others said about the report at

Portland Press Herald: http://www.pressherald.com/2015/04/28/casco-bay-healthy-but-threats-loom/

The Forecaster: http://www.theforecaster.net/news/print/2015/04/28/casco-bay-study-links-ocean-acidity-shellfish-decl/230967

MPBN radio: http://news.mpbn.net/post/report-chemistry-maines-casco-bay-changing-rapidly

The Working Waterfront: http://www.islandinstitute.org/working-waterfront/casco-bay-health-good-bears-watching-says-friends-group

Anything but “Fresh” . . .

Stormwater Is Anything but Fresh . . .

After a rainstorm, millions of gallons of polluted stormwater pour into Casco Bay.
After a rainstorm, millions of gallons of polluted stormwater pour into Casco Bay.


The same scene from the Eastern Prom on a dry, sunny day paints a healthier picture.

In recent years, long dry periods have been followed by heavy rains that dump inches of water in a few hours or days, sending plumes of polluted stormwater into Casco Bay. Millions of gallons of raw sewage, industrial wastes, fertilizers and pet wastes from yards, oil slicks from city streets, and toxins from tailpipes and smokestacks are flushed into Casco Bay.

As he gazes out over a brown bay after yet another torrential rain, Casco Baykeeper Joe Payne knows the coffee-colored stain spreading across the water’s surface is anything but fresh water. “This toxic soup can sicken swimmers, make seafood unsafe to eat, and harm marine life,” Joe says. Rainstorms in and of themselves are not bad, but the polluted runoff they flush into Casco Bay reminds us that we all need to do more to protect the waters that define our community. It takes a community to address the problems and ensure a cleaner, healthier Casco Bay for future generations.

You can help. Support Friends of Casco Bay by donating or volunteering.

Thank You to Our Volunteer Citizen Scientists

It Takes a Community to Protect the Bay

Friends of Casco Bay’s most valuable asset is a committed corps of volunteers. Together, they have donated more than 150,000 hours of service over the past 25 years. Our neighbors around the Bay help us tackle issues and projects in ways that significantly enhance the work of our staff of ten.

We piloted our Water Quality Monitoring Program in 1992 to prove that volunteers could collect reliable data. The U.S. Environmental Protection Agency has repeatedly given our monitoring methods its scientific “seal of approval.” Our communities and governments could not afford to pay professional scientists and contractors for the work our volunteer citizen scientists do for free. Our volunteers sample on 10 selected Saturdays, at 7 a.m. and 3 p.m., from April through October.

Our volunteers and staff collect data sets that:

  • Ground our advocacy with credible, scientifically accurate facts
  • Are legally defensible and are incorporated into Maine’s biennial report to Congress under the Clean Water Act
  • Create a portrait of Casco Bay that documents baseline conditions and environmental changes
  • Inspire stewardship by encouraging community service and volunteerism
  • Stimulate and support research by government agencies, universities, and scientific institutions

Read the next section of the report How Healthy Is Casco Bay?

Lawns Are to Blame for Much of the Nitrogen and Toxic Chemicals in the Bay

Joe’s footprints in green slime at a cove in Falmouth

Casco Baykeeper Joe Payne received a panicked call from a member of Friends of Casco Bay who lived on a cove in Falmouth. He asked Joe to discover the polluter whose actions had turned his scenic inlet bright green. When Joe walked out onto the flat to investigate, his boots sank four inches into green slime. He observed that the member had recently installed a culvert under the driveway that channelled rainwater runoff directly into the cove. He turned to his worried friend and said, “You did this.” The culvert was collecting runoff from fertilized yards in the neighborhood, stimulating a lush growth of green algae across the entire cove.

Friends of Casco Bay’s stormwater monitoring reveals that this neighborhood is not the only one over-fertilizing the Bay. We have found nitrogen and lawn care pesticides in waters around Casco Bay.

Because our advocacy is grounded in science, we worked in conjunction with the Maine Board of Pesticides Control to collected water samples around Casco Bay. Chemicals we found are shown on this map.

When Friends of Casco Bay tested stormwater for pesticides in a South Portland waterfront neighborhood, we found Diazinon and 2,4D, a component of weed and feed products. This prompted further testing at every coastal community around Casco Bay. We detected more pesticides flowing into the Bay in stormwater. Our findings inspired our BayScaping program, which teaches residents how to reduce their use of lawn chemicals.

Pesticides and fertilizers can harm marine life, as well as children and pets. But the good news is there are simple ways you can grow a green lawn that keeps Casco Bay blue.

BayScaping will save you time, save you money, save your lawn, and save the Bay! Join your neighbors, and learn more at cascobay.org/bayscaping.

Read the next section of the report What Is Our Coastal Future?

Nitrogen—Can’t Live Without It, Can’t Live With Too Much of It

Click the Nitrogen Concentrations Map to see a larger version.

All living things need nitrogen to grow. Nitrogen stimulates the growth of plants—both on land and in the ocean. In the marine environment, nitrogen jumpstarts blooms of algae—seaweed and phytoplankton, the tiny plants that form the base of the ocean food chain and provide half the oxygen we breathe. But an overdose of nitrogen triggers excessive growth of nuisance, and even harmful, algae. As these plants decay, bacteria take oxygen out of the water and release carbon dioxide into our coastal waters.

The map below shows concentrations of nitrogen around the Bay. There is a very clear trend of decreasing nitrogen away from shore. This indicates that land-based sources are contributing excess nitrogen to our waters. The farther offshore, the better the water quality!


Read the next section of the report Where Does All This Nitrogen Pollution Come From?

The Report: A Changing Casco Bay

A Changing Casco Bay: The Bay Where You Work and Play Is at Risk

Learn How You Can Help Protect the Health of Casco Bay

For a full version of the report A Changing Casco Bay in PDF, please use this link: https://drive.google.com/file/d/0B_dTKz-k7OLmQzRlWGxFaXhwNGM/view?usp=sharing

Valued for its rich diversity of marine life, Casco Bay was designated an Estuary of National Significance by the federal government in 1990. A technical report from the National Oceanic and Atmospheric Administration on environmental benchmarks found that Casco Bay had twice as many marine organisms as other temperate bays. Since 1989, Friends of Casco Bay has been working to improve and protect the environmental health of Casco Bay.

The dots indicate work that Friends of Casco Bay volunteers and staff have done around the Bay over the past 25 years. Click on the image to see a larger version.


Report Sections

Click on any topic below to jump to that section.

What’s Beneath the Beautiful View?

It Takes a Community to Protect the Bay

How Healthy Is Casco Bay?

Trends in Water Quality

The Double Whammy—Climate Change and Nitrogen Pollution

Nitrogen—Can’t Live Without It, Can’t Live With Too Much of It

Where Does All This Nitrogen Pollution Come From?

It Shucks to Be a Clam

What Starts on Our Lawns Ends Up in Our Bay

What Is Our Coastal Future?

YOU Can Make a Difference

Anything but “Fresh”. . .


Casco Bay by the Numbers

236,483 = Number of residents living in the Casco Bay watershed, from Bethel to the Bay (2010)

1 in 5 = Number of Mainers living in the Casco Bay watershed

578 = Miles of shoreline around the Bay

200 = Approximate area of water in the Bay in square miles

785 = Islands and exposed ledges in the Bay

$628,143,000 = Value of ocean related activities on and around Casco Bay (2011)


Working Waterfront and Scenic Postcard

Casco Bay extends from Two Lights in Cape Elizabeth to Cape Small in Phippsburg, encompassing 13 coastal communities, including two of Maine’s largest cities, Portland and South Portland, and two of Maine’s newest towns, Long Island and Chebeague Island. The Casco Bay watershed collects water across a landscape of nearly 1,000 square miles, from 42 communities between Bethel and the coast.

Casco Bay is an estuary, where rivers and tides converge. Rivers add nutrients, tides deliver cold, oxygen-rich seawater, and relatively shallow depths provide protected habitat. These factors make our estuary the feeding, breeding, and nursery grounds for 850 species of marine life in Casco Bay, from microscopic plants to migrating pilot whales, and for 150 kinds of waterbirds that nest here.

The circulation of water around Casco Bay is affected by runoff from rivers and streams, tidal action, currents, winds, and geography. Many small rivers, including the Fore, Presumpscot, Harraseeket, Royal, and Cousins, empty directly into Casco Bay, but their collective volume cannot match the influence of the Kennebec River. Even though it is not in the Casco Bay watershed, we have detected runoff from the Kennebec at Halfway Rock, nearly nine nautical miles from where the river enters the ocean.

Casco Bay is both a working waterfront—a port of call for cruise ships, oil tankers, and bulk cargo transports—and a scenic postcard of historic forts, stalwart lighthouses, and secluded anchorages.

In the mid-1800s, tanneries, foundries, slaughterhouses, and shipyards crowded the Casco Bay waterfront. Later, power plants, filling stations, tank farms, and discharge pipes from industry and sewage treatment plants were added to the shoreline. Though many of these pollution sources have been removed, polluted runoff, overflows from sewage pipes en route to sewage treatment plants, boater sewage, the threat of oil spills, and the effects of climate change jeopardize the health of the Bay.

For over 23 years, staff and volunteers have been collecting data for Friends of Casco Bay, to give us a better understanding of the health of our coastal waters. This report focuses on nitrogen, oxygen, water clarity, pH, and pesticides, to create a comprehensive overview of the water quality of the Bay.

Read next section of the report What’s Beneath the Beautiful View?

Thank You to Our Volunteer Citizen Scientists