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The State of the Bay: 50 years of the Clean Water Act and 30+ Years of Advocacy, A Casco Bay Matters Event

Please join us online on Wednesday, May 18, from noon to 1 p.m. for The State of the Bay: 50 years of the Clean Water Act and 30+ Years of Advocacy, A Casco Bay Matters Event.

This event kicks off our year of celebrations honoring the 50th Anniversary of the Clean Water Act and our community’s work to improve and protect the health of Casco Bay.

Our guest speaker, Curtis Bohlen, is an exemplary field scientist and data analyst, and Director of the Casco Bay Estuary Partnership. Every five years the Partnership gathers data from scientists and researchers around Casco Bay, crunches the numbers, and publishes the State of the Bay Report – a comprehensive overview of conditions in the Casco Bay watershed and how it is changing.

At the event, Curtis will share insights from the State of the Bay Report and reflect on how the Clean Water Act has helped improve the health of Casco Bay. He will be joined by Casco Baykeeper Ivy Frignoca and Staff Scientist Mike Doan to discuss current challenges the Bay is facing and how the Clean Water Act can help us address them.

You will also have the opportunity to ask questions about the health of Casco Bay, the Clean Water Act, and other issues facing our coastal waters.


Register Now


What: The State of the Bay: 50 years of the Clean Water Act and 30+ Years of Advocacy, A Casco Bay Matters Event.

When: Wednesday, May 18, Noon – 1 p.m.

This event will take place via Zoom. You must register to attend. We would love for you to join us.

Nabbing Nitrogen: A Clean Water Act Day of Action

Join us to Nab Nitrogen in Portland Harbor, on Sunday morning, August 7! You will help us collect water samples around the Harbor to create a snapshot of nitrogen conditions and we need your help.

Picture yourself with 100+ other community members collecting simultaneous water samples on the water and along the shores of greater Portland Harbor, as well as on and around Little Diamond, Cushing, and Peaks Islands. We will scoop water into jars at 9:30 am from beaches, docks, piers, and all kinds of boats, from those we paddle to those we power. The samples we collect will be analyzed for total nitrogen and used to create a map of nitrogen levels. This data helps Friends advocate to reduce nitrogen pollution. 

Email volunteer [at] cascobay [dot] org to let us know you are interested in joining our day of action.

Bay temperatures rise as oxygen levels dip

Friends of Casco Bay has been collecting water quality data on the health of the Bay for 29 years. A recent analysis of our seasonal long term dataset shows that water temperatures are on the rise in Casco Bay.


On average, water temperatures in Casco Bay are increasing at an approximate rate of 1°F every decade.*

“It’s alarming to see we’re going in the wrong direction,” said Staff Scientist Mike Doan. “There are so many ways that warmer water can impact the Bay. A primary concern is that warm water species are moving in and cold water species are moving out. Invasive green crabs, for example, thrive when the Bay is warmer. On top of species shifting, we are also looking at a system that is increasingly susceptible to nitrogen pollution. And that’s only the tip of the iceberg.”

When Mike says warmer waters make the Bay more susceptible to nitrogen pollution, he is thinking about how excess nitrogen can lead to lower levels of oxygen in the water. Nitrogen pollution comes from sources such as stormwater and wastewater treatment facilities. When excess nitrogen enters the Bay, it can spur the rapid growth of plant life and algae. When these plants inevitably decompose, they can consume so much of the oxygen in the water that aquatic animals like fish and shellfish struggle to breathe, and can even die.

On the whole, Casco Bay contains healthy levels of oxygen. However, water temperature and oxygen have an inverse relationship. Warm water holds less oxygen than cold water, and as water temperatures in the Bay rise, Mike has observed a corresponding decline in dissolved oxygen (a measure of how much oxygen is in the Bay).


On average, levels of dissolved oxygen are healthy in Casco Bay but are slowly decreasing at an approximate rate of 0.1 mg/L every decade.*

“There’s a very healthy amount of oxygen in the Bay right now, and the decline we’re observing is moving at a slow pace,” said Mike. “However, it’s important to keep our eye on this trend. As climate change causes the Bay to warm, oxygen levels will continue to decrease. With it, the impacts of nitrogen pollution and associated drops in oxygen will grow.”

Scientists up and down the New England coastline are reporting similar trends in temperature and dissolved oxygen. At Friends of Casco Bay, these trends are based on Mike’s analysis of a subset of 29 years of our seasonal sampling data. Specifically, Mike looked at data from three locations in the Bay that we access by boat near Fort Gorges, Clapboard Island, and in Broad Sound. At each of these sites we collect data at the water’s surface, and then every two meters down to the bottom of the Bay, to create a “profile” of the water column. Every one of these data points is included in Mike’s analysis, making him confident that these trends accurately reflect changing conditions in Casco Bay.


* The exact rates: water temperatures are rising at 0.99°F per decade and dissolved oxygen levels are decreasing at 0.091mg/L per decade.

Crabs, HABs, Sharks, and More… A Casco Bay Matters Event

Great white shark image provided by Matt Davis, Maine Department of Marine Resources

Join us next Wednesday for an illuminating discussion with guest scientists who are doing cutting edge research in Casco Bay: Crabs, HABs, Sharks, and More… A Casco Bay Matters Event.

Green crabs, harmful algal blooms (HABs), and great white sharks are drawing increasing attention around Casco Bay. Have these sea creatures always been here? Is climate change influencing their presence? 

Changes in coastal chemistry are impacting shellfish populations, while rising seas and other forces are eroding salt marshes. What can we do to protect our vital resources and habitats?

Find out answers to these questions by joining Staff Scientist Mike Doan and Casco Baykeeper Ivy Frignoca as they moderate a panel of guest scientists sharing their research on each of these topics in Casco Bay. All panelists will be available to answer your questions after their presentations.


Our panel of guest scientists includes: 

Matt Davis, from Maine Department of Marine Resources, monitoring great white sharks

Sara Randall, from Downeast Institute, researching shellfish and coastal chemistry

Marissa McMahan, from Manomet, studying invasive green crabs

Bryant Lewis, from Maine Department of Marine Resources, tracking harmful algal blooms

Matt Craig, from Casco Bay Estuary Partnership, restoring salt marshes


You must register to join this event. We would love for you to join us. 

Register Now

Water Reporter tracks dune restoration

Sophia McNally knows Willard Beach in South Portland well. She grew up in the neighborhood on nearby Preble Street. In high school she worked as a lifeguard at Willard, watching over swimmers in Simonton Cove, which is part of Casco Bay. Today, Sofia is helping Friends of Casco Bay keep watch over this popular beach, which has had a rough year, to say the least.

On October 26 a section of sewer pipes that run underneath the dunes on Willard Beach broke, spewing untreated sewage up through the dunes into Casco Bay and into basements and crawl spaces of nearby homes. This event was separate from the oil spill that hit the beach in August. The City of South Portland quickly responded by closing the beach and digging up and replacing the broken sewer.

Unfortunately, these critical repairs demolished a portion of the beach’s dunes and their fragile vegetation. Sand dunes are an important part of a healthy coastal ecosystem. They are vital habitat and play an increasingly crucial role in protecting upland properties as climate change causes storms and surf to intensify.

Casco Baykeeper Ivy Frignoca and Interim Director Will Everitt visited Willard Beach shortly after the sewer break was repaired. They assessed the site and connected with local residents, some of whom were worried about the loss of the sand dunes. Ivy then called the Maine Department of Environmental Protection and the City of South Portland. She learned there was already a plan underway to replant the dunes with native vegetation to stabilize them before winter storms batter the beach. Within a few days, the lost portion of the dunes was reestablished and planted with native plants.

This is where Sofia comes in.

She has been tracking whether the restoration effort is taking root. On her walks along the beach Sofia has been photographing the replanted native grasses and vegetation, as well as the healthy, undisturbed dunes further along the beach. Over time, her photos will be invaluable for assessing the restoration effort.

Sofia says that documenting the dunes is a lot of fun. “It makes you feel good,” Sofia said. “You think: I’m going to take a walk on Willard Beach and take a picture while I’m at it. It makes the walk a little more meaningful.”

Sofia, thank you for being a Water Reporter and helping us keep an eye on the health of Willard Beach and Casco Bay!

Friends’ Volunteers Document Eelgrass Mystery

Volunteer Water Reporters and Friends of Casco Bay staff visited two Brunswick salt marshes in early September, where they shared observational insights and discussed local ecology.


Water Reporter Heather Osterfeld’s post from September 8 shows torn and uprooted eelgrass in Maquoit Bay. Water Reporters have noticed an increase of eelgrass adrift in the Bay since mid-August – from Brunswick west to Freeport, Yarmouth, Cumberland, and Falmouth.

Water Reporters up and down Casco Bay have been documenting an increase of torn and uprooted eelgrass washing ashore from mid-August through September. Falmouth Town Landing, Broad Cove, Wolfe’s Neck, and Maquoit Bay are among the locations where Water Reporters have encountered piles of this ecologically vital, ribbon-like seagrass.

Eelgrass (Zostera marina) grows underwater in the shallows of Casco Bay. Eelgrass meadows are recognized as critical nursery habitat for economically important fish and shellfish. Eelgrass helps to maintain water quality by absorbing nutrients and stabilizing sediments. These seagrass beds can also help the Bay be more resilient to climate change, serving as natural carbon sinks by absorbing carbon dioxide during photosynthesis and making our coastal waters less acidic.

In recent years, some eelgrass beds in Casco Bay have been decimated by rising populations of invasive green crabs. Scuttling through an eelgrass meadow along the bottom of the Bay, adult green crabs clip and uproot eelgrass as they search through bottom sediments for prey, while juvenile crabs may feed on the base of the plant itself. A particularly extreme example of this dynamic occurred between 2012 – 2013, when a boom in the green crab population coincided with the loss of nearly fifty percent of the eelgrass in Casco Bay.

When Casco Baykeeper Ivy Frignoca and Water Reporters take a closer look at the eelgrass that is washing ashore today, they often notice fraying at the stems indicative of green crab mandibles and claws. However, not all of the eelgrass displays this fraying, and Ivy and others speculate that the quantities of dead eelgrass are too large to be caused by green crabs alone.

“We are not sure why we are seeing so much eelgrass washing ashore,” said Ivy. “We have asked state officials to look into this and they are. Continuing to have Water Reporters track where and when eelgrass is coming ashore is key to figuring out what factors may be causing the problem.”

Sometimes being stewards of the Bay means following the clues just as Sherlock Holmes might.

Identifying the difference between the frayed stems of eelgrass clipped by green crabs from eelgrass that has been uprooted by a passing boat or other activity can require a discerning eye. The same kind of observational nuance applies to assessing the potential source of an algal bloom, or hypothesizing which factors are causing a specific stretch of salt marsh to erode. Ivy and Friends’ Community Engagement Coordinator Sarah Lyman met up with Water Reporters in early September, to hone observational skills while discussing questions and sharing insights.

“Many Water Reporters have an intimate familiarity with specific parts of the Bay. When we come together to share our knowledge and perspectives, we all leave knowing more about each other and the Bay,” said Sarah. “That’s what I love about Water Reporter: these folks that care about this place are learning alongside us and teaching us at the same time.”

Sarah and Ivy will be organizing more meetups for Water Reporters around the Bay in the coming months. To stay up to date on Water Reporter events and help us keep an eye on changing conditions in Casco Bay, join us.

What did we see on the Bay this summer?

Last week over 165 Friends of the Bay joined Casco Baykeeper Ivy Frignoca and Staff Scientist Mike Doan online at our latest Casco Bay Matters Event: What Casco Bay Is Telling Us.

Here is a recording of the event for those of you who were unable to attend or would like to revisit the conversation.

Every year, Ivy and Mike traverse the Bay by land and boat from May through October, collecting water quality samples and speaking with those who live, work, and play on the water. At last week’s Casco Bay Matters event, Ivy and Mike shared their observations from this past field season, what our data are telling us about the health of the Bay, and what we all need to do moving forward to keep Casco Bay blue.

If you don’t have time to watch the whole recording, here are a few clips of key moments you may find interesting:

CLIP #1: In this 90-second clip, Staff Scientist Mike Doan breaks down what he sees in the salinity data (the saltiness of seawater) from our Continuous Monitoring Station in Yarmouth. This year the Bay was particularly salty and Mike has thoughts as to why.

CLIP #2: What does the construction project surrounding Portland’s Back Cove have to do with the health of Casco BayIn this 2 minute clip, Casco Baykeeper Ivy Frignoca explains how the big construction project that you can see from I295 reduces pollution while accounting for the impacts of climate change.

CLIP #3: In this 90-second clip, Casco Baykeeper Ivy Frignoca explains how Volunteer Water Reporters are informing our advocacy and helping us track changing conditions seen on Casco Bay.

Want to watch the full 60-minute eventHere it is!

Data from our seasonal sampling program and our three Continuous Monitoring Stations can be viewed at cascobay.org/our-work/science/.

A View from the Hill: The Bay Rests

Friends of Casco Bay Board President Sandy Marsters recently wrote an ode to the Bay in fall, for his regular column with the Portland Phoenix. “There is calm as the Bay breathes with the tides,” writes Sandy, “great inhales and exhales that roll the stones round onshore, polish the sea glass, break in long whispers along the sand.” You can read Sandy’s full column about the beauty of the Bay in autumn, here.

You’re invited: What Casco Bay is Telling Us

Casco Baykeeper boat on the water at dawn

Casco Bay is changing and changing quickly. Join Casco Baykeeper Ivy Frignoca and Staff Scientist Mike Doan for a conversation about what Casco Bay is telling us and what we, as a community, need to do moving forward. On Wednesday, October 27, grab your lunch, log on to Zoom, and join the conversation. Ivy and Mike will be sharing with us their observations and experiences from this field season, what our data are telling us, and how you can help as we work to improve and protect the health of Casco Bay.

You must register to join this event. We would love for you to join us.


What: What Casco Bay Is Telling Us: A Casco Bay Matters Event

When: Wednesday, October 27, Noon to 1 p.m. 

This event will take place via Zoom. We will send you instructions for joining the event after you register.

Looking back and looking ahead: leadership at Friends

Dear Friends,

It has already been three weeks since we gathered with 200 Friends of the Bay to celebrate the career, contributions, and retirement of our longtime Executive Director, Cathy Ramdsell. Cathy’s send-off party, held outdoors at Portland Yacht Services’ boatyard, marked our first in-person event since the onset of the pandemic. It was heartwarming and rejuvenating to see so many supporters, partners, and colleagues after so much time apart. Cathy shared it meant the world to her that we could all be together for this watershed moment. You can view photos and revisit that special evening here.

So what’s next?

Friends of Casco Bay’s Board of Directors will officially launch the search for our next Executive Director soon. As Board President Sandy Marsters has said, “We are grateful that Cathy waited for our organization to reach its current state of maturity and stability before moving on to the next phase of her life. Organizationally, we are stronger than ever: our finances are sound, we have a team of interdisciplinary staff producing incredible work, and our visibility is at an all-time high.”

In the meantime, the board has appointed me to serve as Interim Director. Having worked with our exceptional staff, board members, and community since 2006, and knowing our collective passion for Casco Bay, I am honored to serve our organization during this transition.

Here are some examples of the incredible efforts our staff and volunteers have pursued over the past few weeks.

While we were organizing Cathy’s retirement party, we were also responding to an oil spill at Willard Beach in South Portland. The beach was closed for three days as state, local, and private cleanup teams removed 2,000 pounds of contaminated material. Casco Baykeeper Ivy Frignoca toured the beach soon after the spill was reported. You can read about Ivy’s experience at the cleanup here.

The spill was a stark reminder that protecting the health of the Bay requires vigilance.

This is why we are delighted to have more than 375 volunteer Water Reporters helping us keep watch over Casco Bay. Some Water Reporters recently took a field trip with Ivy and Community Engagement Coordinator Sarah Lyman to the Mere Point Boat Launch to share how they all could be better stewards. If you volunteer your time as a Water Reporter, thank you. If you want to join this observing network, we would love to have you aboard. You can learn more here.

As autumn begins, we are concluding our first summer with three Continuous Monitoring Stations in the water, gathering data every hour on a changing Casco Bay. These data have already begun to offer new insights about our waters. The data is used in our efforts to reduce pollution and help our communities be more resilient to the effects of climate change. To learn about these insights and what else Ivy and Staff Scientist Mike Doan observed this field season, keep an eye out for our next Casco Bay Matters event.

September is coastal cleanup month. Our community members are taking to our coast to pick up trash and litter. In the process they are helping to protect wildlife, collect data for marine debris research and advocacy efforts, and keeping our shores cleaner and safer. Click here for ways you can join them.

Your support means more to us than ever. We look forward to keeping you updated about our search for new leadership and about our work ahead. Thank you for caring about the health of Casco Bay.

With appreciation,

Will Everitt
Interim Director
Friends of Casco Bay

Photos by: Kevin Morris, Ivy Frignoca, and Glenn Michaels

Water Reporter Post of the Month: Linda Stimpson

Horseshoe crabs: ancient animals in Casco Bay

Linda Stimpson has lived in Maine for much of her adult life, but it wasn’t until recently that she first spotted this prehistoric creature – with nine eyes and ten legs – scuttling along the shore of Casco Bay.

In her Water Reporter post from July 12, Linda photographed a horseshoe crab on the stretch of beach between Wolfe’s Neck State Park and Googins Island.

“They’re ancient creatures,” said Linda, referring to the fact that these invertebrates have been on earth for over 300 million years (that is even older than dinosaurs). Despite the threatening impression that may come from their spike covered shell and long pointy tail, “they’re really quite docile,” shared Linda.

Adult horseshoe crabs live deep in the ocean, but they search out sandy shores in the spring and summer to spawn. Once on shore, females dig nests in the sand where they deposit their eggs to be fertilized by males. In Casco Bay, horseshoe crabs are known to spawn in Middle Bay and Thomas Point Beach in Brunswick, though Linda’s photo clearly shows that they also make their way further west. Linda also shared that she recently saw a horseshoe crab on the shores of Mackworth Island.

Horseshoe crabs play an important role in coastal food webs, as their eggs are a nutritious food source for fish, turtles, and migratory shore birds. In addition to their ecological importance, horseshoe crabs play a critical role in modern medicine. Their blood is used to test for the presence of bacterial endotoxins in sterile pharmaceuticals, like artificial joints, intravenous drugs, and even COVID-19 vaccines!

Linda, thank you for keeping an eye out for these ancient animals in Casco Bay, and for being a Water Reporter.