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
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.
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?
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.
A King Tide is an astronomically high tide. A King Tide is a natural, predictable occurrence that happens a few times a year. This provides the opportunity to envision what our coastal areas may experience as sea levels continue to rise. These extra-high tides can help us spot areas that could be most vulnerable to sea level rise. King Tides are also known as perigean spring tides.
Casco Bay will experience a King Tide on Wednesday, February 20th, at 11:18 AM., which is estimated to reach 11.6 feet. A normal high tide in the Bay ranges from 8 to 10 feet.
We are mobilizing our volunteer Water Reporters to help us document the February King Tide to help our us visualize what sea level rise may mean for our region. Between 10:48 and 11:48 on February 20, our volunteers will don their rainboots and pull out their smartphones to capture this extreme tide using the Water Reporter app.
Water Reporter is an easy-to-use “Instagram-like” tool that enables our volunteers to document, catalogue, organize, and share observations of the Bay. This information is aiding our collaborations with other scientists, expand our community engagement by sharing observations on social media, and helping with our advocacy, to illustrate changes happening around the Bay to regulators, legislators, and other policy makers.
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.
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.
Friends of Casco Bay’s newest workhorse—our Continuous Monitoring Station (CMS)—has been amassing hourly data on the health of the Bay for over two years now.
Research Associate Mike Doan is excited to be able to look at the daily, weekly, and seasonal changes in the Bay in far more detail than ever before. Mike was able to make comparisons between the first two years of data, comparisons we will continue tracking year to year. For example, the graph above shows nuances we could not have documented before:
A. The period of late summer-early fall of 2016 was warmer than the same time period in 2017.
B. The winter of 2017-18 turned colder earlier, with water temperatures dropping below 0°C before the end of December. In the previous winter, water temperatures did not drop below 0°C until late January.
C. Overall, spring and summer of 2018 were warmer than the same periods the year before.
On July 20, 2018, we marked the second anniversary of when our Continuous Monitoring Station began recording data off Yarmouth near the coastal midpoint of Casco Bay. The data are providing insights into how climate change and ocean acidification may be affecting the health of our waters.
The Station consists of a modified lobster trap that houses a data sonde and a carbon dioxide sensor, instruments that collect data on many different aspects of water conditions.
Mike is the architect of our Cage of Science. “It’s been a lot of work to get to this point,” admits Mike, “and it is exciting to see the quality and quantity of data we are collecting.” Colleagues have taken notice of how he has been able to outfit an electronic station with accurate, high-tech monitoring equipment at reasonable cost. Several scientists already are using the continuous data.
We look forward to building the long-term data set that will provide a more complete picture of a changing Casco Bay, information that can help our communities assess, mitigate, and adapt to those changes.
Why is water temperature important?
Temperature influences how much oxygen and carbon dioxide the water can hold, the rate of plant growth and decay, and the movement of currents. Temperatures also impact the geographic distribution of marine life. Menhaden (pogies), typically found in the mid-Atlantic, have been showing up in large numbers in Casco Bay. Lobstermen say that lobsters are remaining farther offshore, with fewer showing up in warmer water areas around inshore eelgrass beds. We are seeing species of phytoplankton that were never before documented in Casco Bay.
Thanks to support from Casco Bay Estuary Partnership and generous donors, our Continuous Monitoring Station collects data once an hour, every hour, year round.
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.
Do you want to help keep Casco Bay clean? Volunteer to help out at our public coastal cleanup!
Trash is an unsightly blight that makes it hard for everyone to enjoy a special place like Casco Bay. Litter and marine debris on our shores come from many sources. Careless beach goers, boaters, fishing vessels, and other ships can leave trash behind. Stormwater washes trash from yards and parking lots into storm drains that empty into Casco Bay.
When you volunteer to help us with a cleanup, you are:
Collecting data on the types and size of materials removed
The data is then used locally and internationally for marine debris advocacy efforts
Making our shores cleaner and safer
Ensuring our coast is a place people can go to recreate and relax
Helping protect wildlife
Supporting the local economy as our coast is part of Maine’s brand; it as an ideal tourist attraction that creates a stream of revenue that supports our community
Every hour and every day, the Continuous Monitoring Station—a.k.a our “Cage of Science”—is building a more complete picture of the seasons beneath the Bay. Thanks to support from Casco Bay Estuary Partnership and generous donors, the Station collects measurements of temperature, salinity, pH, dissolved oxygen, carbon dioxide, and chlorophyll fluorescence year-round. Every other week, Research Associate Mike Doan cleans and calibrates the equipment, and downloads and graphs the data to track conditions in the Bay.