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A call to action before Tuesday: make your voice heard

Photograph by Kevin Morris

Casco Bay needs your help! Please take a few minutes to let legislators know you are concerned about climate change and the health of Casco Bay.

On Tuesday, April 2, at 1 p.m., the Committee on Marine Resources of the Maine Legislature is holding a public hearing on a bill we strongly support: LD 1284, “An Act to Create the Science and Policy Council on the Impact of Climate Change on Maine’s Marine Species.”

The bill will establish a council made up of legislators, scientists, resource harvesters, and other stakeholders, with a mission to evaluate the impacts of climate change on Maine’s marine species and to make statewide policy recommendations.

This bill moves Maine to action on addressing and adapting to climate change, ocean acidification, sea level rise, and other threats to the health of our coastal waters. We believe Maine must act now to protect coastal habitats and marine species.

We ask you to urge the Committee on Marine Resources to vote in favor of LD 1284. Let them know you are concerned about climate change and its impacts on Casco Bay and on all of Maine’s marine resources.

Please email the committee by Tuesday morning, April 2.

Committee Members to email:

For a quick and easy way to share your support click here to email the Committee Clerk at MAR@legislature.maine.gov,.

To email the committee members directly, can copy and paste these into the “to” line of your email. This will work better on some devices and email platforms than others.

MAR@legislature.maine.govDavid.Miramant@legislature.maine.gov, Dana.Dow@Legislature.Maine.gov, Eloise.Vitelli@legislature.maine.gov, Jay.McCreight@legislature.maine.gov, Robert.Alley@legislature.maine.gov, Pinny.Beebe-Center@legislature.maine.gov, Lydia.Blume@legislature.maine.gov, William.Faulkingham@Legislature.Maine.gov, Allison.Hepler@Legislature.Maine.gov, Sherman.Hutchins@Legislature.Maine.gov, Kathy.Javner@Legislature.Maine.gov, Genevieve.McDonald@Legislature.Maine.gov, Will.Tuell@legislature.maine.gov, Michael.Russo@Legislature.Maine.gov, Deirdre.Schneider@legislature.maine.gov

Add an subject, being sure to mention that you support LD 1284.

Here are suggested talking points for your email — we strongly recommend that you put these in your own words. Links below provide more information.

Dear Senator Miramant, Representative McCreight, and Members of the Committee on Marine Resources:

I am writing to you to urge you to vote in favor of LD 1284, “An Act to Create the Science and Policy Council on the Impact of Climate Change on Maine’s Marine Species.”

Maine’s coastal waters are changing and changing quickly. Friends of Casco Bay has been tracking water temperatures for over 25 years. On average, the data show a 2.5° F increase in water temperatures since 1993.

About 30% of the carbon dioxide released into the atmosphere is being absorbed by the ocean. This is increasing the acidity of our marine waters and reducing the availability of the material (calcium carbonate) that clams, mussels, and other shellfish need to build their shells. Recent data indicate that for nearly half the year, levels of calcium carbonate in Casco Bay are not sufficient for shell-building.

Our marine heritage and economy depend upon healthy coastal waters. The Science and Policy Council that LD 1284 will create will help move Maine forward on addressing and adapting to changes that threaten our marine resources.

Thank you for your time and service to Maine.

Sincerely,

–Your name and town you live in

Once you have emailed the committee, please let us know by emailing me back at keeper@cascobay.org. I will be testifying at the hearing on Tuesday, and it would be great to know that we have your support.

Thank you for making your voice heard for Casco Bay!

 

More information:

We have a wealth of information about the impacts of climate change on Casco Bay: https://www.cascobay.org/climate-change-ocean-acidification-and-you/

LD 1284 was proposed by Representative Lydia Blume (York), who is a member of the Committee on Marine Resources. You can read the official language of the bill here.

LD 1284 has been selected by the Environmental Priorities Coalitiona group of 34 environmental organizations, as one of its five priority bills to address climate change in Maine.

As we shared with you at our Casco Bay Matters event, Governor Mills has proposed an all-encompassing Climate Change Council. Her proposal, which will be considered in separate legislation, will likely incorporate the council created by LD 1284 into a subcommittee of her omnibus council. We support the Governor’s plan and want to be sure that there is adequate focus on the marine environment — which is why it is so important that you make your voice heard on this issue.

Here is the official web page for the Committee on Marine Resources: http://legislature.maine.gov/committee/#Committees/MAR.

You can listen live to the hearing on Tuesday by clicking here: http://legislature.maine.gov/Audio/#206

Climate Change, Ocean Acidification, and You

Climate Change Science and Data

  • The climate is changing faster than expected. Greenhouse gases, such as carbon dioxide and methane, are the culprits. The burning of fossil fuels for homes, industry, and transportation releases almost 10,000 million metric tons of carbon dioxide into the atmosphere every year. 1
  • Carbon dioxide is changing not only our climate, but also the chemistry of the ocean. About 30% of the carbon dioxide we release into the atmosphere is absorbed by the ocean. 2 In marine water, carbon dioxide decreases pH and increases acidity through a process known as ocean acidification.
  • Excess nitrogen from sewage treatment plants, polluted stormwater, and fertilizers, is also adding carbon dioxide into nearshore waters through a process known as coastal acidification. 3
  • Nitrogen can fertilize massive algal growth in our waters. When the algal blooms die, decomposition depletes the area of life-giving oxygen and releases carbon dioxide, acidifying the water.

The impacts of climate change are evident right here in Casco Bay

Warmer Waters

Friends of Casco Bay has been tracking water temperatures for over 25 years. On average, our data show a 2.5° F increase in water temperatures since 1993.

Sea Level Rise

As water warms, it expands, and the sea encroaches on our coastline. Coastal observers and property owners are reporting an increase in erosion.

Increasing Precipitation

Maine has seen a six-inch average increase in annual precipitation since 1895, further threatening coastal properties. 4

Threats to the Ocean Food Web

More carbon dioxide in our waters means there is less shell-building material (calcium carbonate) for clams, mussels and oysters, as well as for tiny critters at the base of the ocean food chain. The saturation state of calcium carbonate is a key measurement of shell-building material for many organisms. Shell formation becomes more difficult when the amount of available calcium carbonate falls below a 1.5 saturation state. 5 Our recent data indicate that for nearly half the year, levels of calcium carbonate in Casco Bay are not sufficient for shell-building.

What do these changes mean for Casco Bay?

  • Research Associate Mike Doan with our Continuous Monitoring Station. The Station houses a number of instruments that collect data on carbon dioxide, temperature, salinity, oxygen, chlorophyll, and pH, hourly, 365 days a year. This large quantity of data is necessary to accurately track changes in the Bay from climate change, including ocean and coastal acidification.

    As marine waters become more acidic, we can anticipate more pitting or dissolution of the shells of many commercially viable species in Casco Bay.

  • Rising water temperatures are linked with shell disease, directly impacting our lobster fishery and tourism industries.
  • Climate change is bad news for clams because green crabs — which eat juvenile shellfish — thrive in warming waters. 6
  • The distribution and populations of marine species in the Gulf of Maine are shifting. Scientists and lobstermen are documenting the shift in distribution of Maine’s iconic lobsters north and east.
  • Copepods are tiny crustaceans that are the main food source for juvenile lobsters. In laboratory experiments, copepods raised in conditions that simulate the climate changes occurring in the Gulf of Maine were less fatty. With a less healthful diet, young lobsters must divert energy from growth and resisting disease to finding enough food to survive. 7

What is Friends of Casco Bay doing?

  • We helped form the Maine Ocean and Coastal Acidification Partnership (MOCA) to coordinate climate change research and policy change work. MOCA is a diverse coalition of researchers, policy experts, lawmakers, aquaculturalists, and seafood harvesters. We are working to create an action plan for Maine to protect the health of our coastal waters.
  • LD 1284 has been selected by the Environmental Priorities Coalition, a group of 34 environmental organizations, as one of its five priority bills to address climate change in Maine.
  • Our Water Reporter volunteers are recording observations of how the Bay is changing. These observations strengthen our advocacy efforts as these reports are shared with regulators, legislators, and other decision makers, alerting them to conditions in the Bay.

What can you do?

  • Tell your legislators to support LD 1284 to create a science and policy advisory council to address the impacts of climate change on Maine’s marine species.
  • Join Water Reporter. Your observations combined with those of other volunteers around the Bay will provide a better understanding of changing conditions.  

References

  1. T.A. Boden, R.J. Andres, G. Marland, Global, Regional, and National Fossil-Fuel CO2 Emissions, Research Institute for Environment, Energy, and Economics, Appalachian State University, 2017. https://cdiac.ess-dive.lbl.gov/trends/emis/overview_2014.html
  2. N. Gruber, D. Clement, R. Feely, et al., The oceanic sink for anthropogenic CO2 from 1994 to 2007, Science, 2019. http://science.sciencemag.org/content/363/6432/1193
  3. J. Weiss, Marine Pollution: What Everyone Needs to Know, Oxford University Press, 2015.
  4. I. Fernandez, C. Schmitt, E. Stancioff, et al., Maine’s Climate Future: 2015 Update, The University of Maine, 2015. https://mco.umaine.edu/pubs/pdf/mcf-2015.pdf
  5. J. Ekstrom, L. Suatoni, S. Cooley, et al., Vulnerability and adaptation of US shellfisheries to ocean acidification, Nature, 2015. http://pacshell.org/pdf/Ekstrom_etal2015.pdf
  6. E. Tan, B, Beal, Interactions between the invasive European green crab, Carcinus maenas, and juveniles of the soft-shell clam, Mya arenaria, in eastern Maine, USA, Journal of Experimental Marine Biology and Ecology, 2015. https://downeastinstitute.org/wp-content/uploads/2018/08/tan-beal-2015.pdf
  7. Copepods cope with acidification, Bigelow Laboratory for Ocean Sciences, 2018. https://www.bigelow.org/news/articles/2018-04-10.html

Ocean Acidification, Climate Change, and You: A Casco Bay Matters Event

Climate change is affecting the health of Casco Bay faster than anyone could have predicted. Warming temperatures and increasing acidity threaten the ocean and the livelihoods of those who depend on the sea. Research is showing that changes in our coastal waters from climate change are putting lobstering, clamming, and aquaculture at risk.

Friends of Casco Bay invites you to attend Ocean Acidification, Climate Change, and You, a free event, open to all.

Staff scientist Mike Doan will talk about the warning signs we see in our monitoring data. Casco Baykeeper Ivy Frignoca will share some of the impacts to our marine species and how Mainers are working together to respond to these threats. They look forward to your questions following the presentation.

Healthy marine waters are vital to Maine’s economy and quality of life.This is such an important issue that we are hosting this presentation at three locations in the coming weeks: Portland, South Portland, and Brunswick.

Ocean Acidification, Climate Change, and You

Come to the event nearest to you, or all three!

Weather cancellations will be posted here on this page on our website, and our Facebook event page.

All events are free and open to the public.

Portland Event

Monday, March 18, 2019
5:30 – 6:30 pm
Portland Public Library,
5 Monument Way, Portland, ME 04101

Add to Calendar

Please note: this date was listed incorrectly in the Forecaster. March 18 is the correct date.

South Portland Event

Monday, March 25, 2019
5:30 – 6:30 pm
Southern Maine Community College,
Jewett Hall, 77 Fort Rd, South Portland, ME 04106

Add to Calendar

Brunswick Event

Tuesday, April 9, 2019
5:30 – 6:30 pm
Curtis Memorial Library,
23 Pleasant St, Brunswick, ME 04011

Add to Calendar

You can see our Bay Paper on these topics here.

Cover photograph by Kevin Morris

See what is going on beneath the surface. Check out our data!

Photograph by Kevin Morris • Aerial support provided by LightHawk

On July 20, 2016, our Continuous Monitoring Station began recording data hourly, 365 days a year. We are excited to share the first two and half years of data, collected at our water quality monitoring site in Yarmouth, near the coastal midpoint of Casco Bay. We will update these graphs monthly, so come back often and see for yourself how Casco Bay is changing.

See the data

See sea critters and our Cage of Science

Watch this short video about the Cage of Science!

You may know that Friends of Casco Bay’s Continuous Monitoring Station—AKA our “Cage of Science”—gives us vital data about the health of the Bay. But did you also know that observations of what sea life is growing on and hanging out in the station also give us important information about conditions of our waters? In this video, Research Associate Mike Doan shows us some of the sea critters that visited the Cage of Science in August.

Thanks to support from Casco Bay Estuary Partnership and generous donors, our Continuous Monitoring Station collects data once an hour, every hour, year round.

The looming question for the future— How is Casco Bay changing?

Photograph by Kevin Morris • Aerial support provided by LightHawk

We see water itself as fundamental habitat. When water quality deteriorates, eelgrass, plankton, clams, and other marine creatures suffer. Thanks to our 25-year data set on water quality in Casco Bay, we now have a better overall understanding of the health of the Bay. We understand when and which areas of the Bay are likely to exhibit challenged water quality conditions.

Armed with this baseline data, we can now begin to address the question How is the Bay changing?—thus, the establishment last year of our first automated Continuous Monitoring Station. We will also continue to monitor selected sites at the surface, to supplement the historical data set compiled by our Citizen Stewards Program. And, we will look more intensively, using surface-to-bottom transects, at those regions of the Bay which present challenged conditions. New data and observations may help us begin to understand how climate change, excess nitrogen, and the changing chemistry of Casco Bay may be impacting the ocean food web.

Our Nabbing Nitrogen event in 2016 signaled to us that there is a huge reservoir of goodwill from people who want to help protect the health of the Bay and are willing to do that in short bursts of data collection efforts. We foresee new volunteer opportunities in this type of data collection, as well as in expanding other community service projects, such as coastal clean-ups, storm drain stenciling efforts, and issue-education events to inspire Champions for the Bay.

Citizen Steward volunteers will continue to be key to our organization as they help us move into this next phase of work to improve and protect the environmental health of Casco Bay. Casco Bay belongs to all of us, and this Bay is fortunate to have so many Friends.

Cathy L Ramsdell, CPA, CGMA
Executive Director

Cathy Ramsdell Interview

MOCA Partners

Working With . . . MOCA Partners

MOCA Partners
The Maine Ocean and Coastal Acidification Partnership (MOCA) is asking – and answering – the hard questions: “Why is ocean acidification happening?” and “What can we do about it?”

Climate researchers have found that the ocean absorbs about 25% to 30% of the carbon dioxide released into the atmosphere from smokestacks and tailpipes. When this excess carbon dioxide mixes with water, it can make the water more acidic. This is called ocean acidification.

More excess carbon dioxide can end up in coastal waters as a result of nitrogen pollution from fertilizers, stormwater runoff, and sewage. This nitrogen overdose stimulates a population explosion of tiny plants called phytoplankton. When these plants die and decay, bacteria consume oxygen and release carbon dioxide in bays and coves. This creates even more acidic conditions for coastal critters. This is called coastal acidification.

Coastal acidification is one more stressor for shellfish species already challenged by other impacts, such as predation by milky ribbon worms and gluttonous green crabs that flourish in warming waters. Red tides and other harmful algal blooms, exacerbated by nitrogen runoff, may close clam flats to shellfish harvesting for weeks or months.

In 2014, Friends of Casco Bay participated in the Maine Ocean Acidification Study Commission, which issued a report to the Legislature in January 2015, recommending many actions to confront this threat to our fisheries, including establishing an ocean and coastal acidification council. Efforts in 2015 to pass a law creating the council failed to garner government support.

Rather than letting a worthwhile idea die, Friends of Casco Bay, the Island Institute, and University of Maine/Maine Sea Grant formed the Maine Ocean and Coastal Acidification Partnership (MOCA) to coordinate the efforts of government agencies, private organizations, and citizens. Since its first meeting in March 2016, MOCA has held two symposia, organized working groups, and met with coastal legislators.

Outreach events and coordinated water monitoring are planned for 2017.

What can you do about coastal acidification?

  • Eliminate the use of fertilizers on your property
  • Make sure your septic system is doing its job
  • Reduce carbon emissions by driving less
  • Support clean energy policies
  • Opt for meatless Mondays – or more. Eating vegan reduces greenhouse gases significantly
  • Find out more actions you can take at here.
MOCA Partners

MOCA is on the Move

With increasing research showing that coastal acidification is a threat to Casco Bay, here’s what we’re doing about it.

The all-volunteer Maine Ocean and Coastal Acidification Partnership (MOCA) has held two symposia, organized working groups, and met with coastal legislators, all in its first year.

Why do scientists and sea farmers worry about acidifying seawater? Studies by researcher Dr. Mark Green and oyster grower Bill Mook have found that increasing the acidity of seawater can stress sea creatures such as clams, oysters, and mussels. Some shellfish farmers in Maine have already begun storing seawater to use during times when stormwater runoff makes the water unsafe for developing oysters.

Climate researchers have found that the ocean absorbs over 25% of the carbon dioxide released into the atmosphere by smokestacks and tailpipes. This is called ocean acidification. In addition, carbon dioxide ends up in coastal waters from nitrogen pollution from fertilizers, pet wastes, stormwater runoff, and sewage discharges. This nitrogen overdose stimulates a population explosion of tiny phytoplankton. When these plants die and decay in bays and coves, bacteria consume oxygen and release carbon dioxide. This creates even more acidic conditions for coastal critters. This is called coastal acidification.

Dr. Mark Green of St. Joseph’s College in Standish, Maine, is a leading researcher on the impact of coastal acidification on clams. He has been testing how baby clams respond to mud from clam flats along our coast, including Casco Bay. He calls clams the “canaries in the coal mine.” Nitrogen runoff, he asserts, is hampering the ability of clams and oysters to build and maintain their shells. Dr. Green found that clam spat and baby clams simply dissolve at levels of acidity found in some parts of Casco Bay today. He calls this unfortunate condition “death by dissolution.”

Dr. Green’s experiments in the lab inspired us to investigate conditions in Casco Bay. In 2011, we sampled the pH (acidity) of the mud on about 30 clam flats around Casco Bay. In 2012 and 3013, we returned to one of those clam flats to monitor conditions every two weeks across three seasons and varied tide cycles to get a better understanding of how natural fluctuations impacted pH. We also put baby clams (spat) into “clam condos” into a clam flat in Freeport, protected from green clams by screens. After one week and two weeks in the mud, we found significant pitting in their shells, indicating that the shells were dissolving.

Coastal Acidification is one more stressor for shellfish species that already are challenged by other climate change impacts, such as predation by gluttonous milky ribbon worms and green crabs which flourish in warming waters. Red tides or other harmful algal blooms may close clam flats to shellfish harvesting for weeks or months each year. The density and duration of these harmful bloom events may be exacerbated by nitrogen runoff, which provides the nutrients to nourish the red tide organisms.

 

What are we doing about coastal acidification?

 

The good news is that we can do something to fight back against coastal acidification caused by nitrogen pollution. Says Casco Baykeeper Ivy Frignoca, “It’s wonderful to work with so many scientists, harvesters, and policy makers who understand this issue and are working on it before coastal acidification becomes insurmountable.”

 

One way is to find out what we know and what we need to know about coastal and ocean acidification. Friends of Casco Bay and others realized we need a concerted effort to fight the effects of ocean and coastal acidification. In 2014, we participated in the Maine Ocean Acidification Study Commission, which issued a report to the Legislature in January 2015, recommending many actions to confront this threat to our fisheries and marine ecology in general, including establishing an on-going ocean and coastal acidification council.

 

Friends of Casco Bay worked with the Island Institute and University of Maine/Maine Sea Grant to create the Maine Ocean and Coastal Acidification Partnership (MOCA). MOCA volunteers partnership seek to:

  1. Implement recommendations of the Ocean Acidification Study Commission; and
  2. Coordinate the work of governmental agencies, private organizations, and citizens who are studying and implementing means to reduce the impacts of or help adapt to ocean and coastal acidification.

Here are some highlights of MOCA:

March 14, 2016

MOCA held its first meeting, attended by more than 30 scientists, policy makers, and harvesters.

 

June 29, 2016

MOCA hosted a day-long Ocean Acidification Symposium, attended by 110 people, including some of the state’s top researchers and policy makers. Scientists shared their field experiment data and compared notes.

 

November 16, 2016

MOCA hosted a second symposium focused on remediation and policy. More than 50 people gathered at the State House in Augusta to discuss the possibility of developing state/ federal water quality criteria related to coastal acidification. Ivy discussed how we might use existing regulatory tools to reduce nitrogen pollution that exacerbates coastal acidification. The participants formed subcommittees to create an action plan on next steps for confronting ocean acidification through research and legislation.

 

What’s next?

  • Education Casco Baykeeper Ivy Frignoca is working with the MOCA Policy Subcommittee to help organize two MOCA symposia in 2017. They will educate interested citizens and decision makers on cutting-edge science and local and state policies that may be implemented to combat acidification
  • Uniform data collection is the goal of Friends of Casco Bay Research Associate Mike Doan and more than a dozen other scientists on the MOCA Monitoring Subcommittee. They will work together to coordinate and standardize monitoring equipment and procedures on data collection on acidification. This uniformity will provide better understanding of nitrogen inputs into coastal waters.

 

What can you do about coastal acidification?

  • Cut down or eliminate fertilizers on lawns, gardens, and farms.
  • Lobby for and support a town ordinance to limit the use of nitrogen-rich fertilizers.
  • Reduce rainwater runoff and improve sewage treatment.
  • Make sure septic systems are doing their job.
  • Join and/or volunteer with organizations to monitor coastal waters and educate the public.
  • Reduce carbon emissions by driving less or driving a less polluting vehicle
  • Support clean energy production such as solar and wind power
  • Support clean energy policies such as RGGI and the Clean Power Plan
Seastars on Continuos Monitoring Station

Keeping an eye on the Bay 24/7

Seastars on Continuos Monitoring StationImagine working 8,760 hours a year. Friends of Casco Bay has two water quality monitors that do just that: a datasonde, an instrument that can measure several properties of water at once, and a specialized device that only measures carbon dioxide. They are anchored together on the ocean floor in Yarmouth to collect data once an hour, every hour, year round. Appropriately, these high tech tools comprise our new Continuous Monitoring Station. These hard workers have been in place since July 2016.

 

Why is this hourly data vital?

 

The steady flow of data our Continuous Monitoring Station collects will help us detect and document how climate change and other emerging coastal stressors may (or may not) be affecting the Bay. Hourly data will help us identify daily, seasonal, and annual trends and better understand the extent to which ocean acidification may be impacting the water chemistry of Casco Bay. The station may also help us assess sea level rise. The station collects data on oxygen levels, carbon dioxide (CO2), pH (the level of acidity of the water), salinity, temperature, chlorophyll, and water depth.

 

In order to ensure continuous data, we have two datasondes which are swapped and refreshed every two weeks. When he arrives at the dock in Yarmouth, Research Associate Mike Doan has less than an hour to reposition the alternate datasonde so that we don’t miss any of those 8,760 hours of information.

 

Mike hauls up the anchored devices, uploads data from the CO2 sensor to his laptop, and scrapes off marine hitchhikers such as sea stars, tunicates, and algae. “It’s amazing how fast sea creatures occupy any available surface, including our instruments!” says Mike. Before he leaves, he replaces the datasonde with one freshly calibrated and lowers the entire Continuous Monitoring Station back onto the ocean floor. Such attention to detail provides quality assurance that the data is accurate.

 

While this station is busy year around, we continue to enlist volunteers to help us understand the overall health of our marine waters and to identify troubled areas of the Bay. From April to October each year, more than 90 volunteer Citizen Stewards monitor scores of shoreside sites where they measure five parameters of the surface water: pH, salinity, water temperature, water clarity, and oxygen level. If you are interested in becoming a water quality monitoring volunteer, you can learn more about the program here.

 

Our volunteers, staff scientists, and now our automated partners, all play a role in helping us to better understand what is going on in Casco Bay.

 

 

Thank you to funders of this project, including Casco Bay Estuary Partnership, Davis Conservation Foundation, Horizon Foundation, Schwartz Family Fund of the New Hampshire Charitable Foundation, and WEX. We also thank our Members and the many donors, local businesses, and foundations that give us operational support to do our work each year.

 

 

Althea McGirr at LIttle Diamond Island

Althea Bennett McGirr says, “It shucks to be a clam!”

Althea McGirr at LIttle Diamond Island
Althea Bennett McGirr, a Board member since 2011, doesn’t need Friends of Casco Bay to tell her that the chemistry of Casco Bay is changing. She has seen the effects of Coastal Acidification firsthand.

At the annual Labor Day clambake on Little Diamond Island, Althea and her sister Priscilla help out at the end-of-the-season event that draws the community together for a farewell to summer. While the lobsters, sweet potatoes, sausages, and corn are roasting in a fire pit outside the hundred year-old Casino, their job is to wash and de-sand freshly harvested Casco Bay clams.

Althea recalls scooping huge handfuls of clams into 8 heavy kettles to steam them for the feast. Nowadays, they have to place the clams into the pot delicately, or else the shells may end up chipped or even shattered. Althea says that the clams they buy now are smaller and more fragile than the ones she
recalls from years back.

Althea’s observations seem to correspond to observations Friends of Casco Bay has been making over the years. We are studying Coastal Acidification, the problem of increasing acidity from the ocean absorbing carbon dioxide released by the burning of fossil fuels, and, we believe, from excess nitrogen washing into coastal waters by stormwater runoff. Fertilizers, sewage discharges, and pet wastes trigger algae blooms that add excess carbon dioxide to coastal waters.

Pitted Clam
The pitted shell shows that life can be tough for a clam spat in acidic mud.

Our data shows that the acidity of Casco Bay has increased since we began our water quality monitoring program nearly 25 years ago. In 2011, we began sampling the pH (acidity) of mudflat sediments, where soft-shell clams live. We found that the mud nearest to shore was more acidic (had lower pH) than sediments further away from sources of land-based pollution. Higher acidity makes it harder for shellfish to extract calcium carbonate from their environment, the material that clams, mussels, and other mollusks need to build and strengthen their shells.

In the summer of 2014, Friends of Casco Bay installed several clam “condos” in the intertidal mudflats of Recompense Bay in Freeport. Our goal was to see what would happen when we exposed juvenile clams to acidic mud. Research Associate Mike Doan caged baby clams inside PVC tubes and left them in the mud for several days. Microscope photographs of the tiny clam spat showed that after just one week, their shells had become pitted, showing signs of dissolving.