Home » Science: We help you see what is going on beneath the surface of the Bay

Science: We help you see what is going on beneath the surface of the Bay

Before we started monitoring the water quality of Casco Bay, no one knew how healthy or polluted the Bay actually was. Thanks to the data we have been collecting at dozens of shoreside and offshore sites, we can state that the water temperature of Casco Bay has risen by 2.5°F, on average, since 1993.

Our long-term data set is enhanced by our Continuous Monitoring Station that has been monitoring the health of the Bay hourly, 365 days a year, since 2016. Anchored below a pier in Yarmouth, it provides the frequent, high-volume stream of data necessary to accurately track changes that may impact the oysters, clams, lobsters, and eelgrass within the Bay.

“Climate change is happening so rapidly, we needed to add to the way we collect data,” observed Research Associate Mike Doan. Since July 20, 2016, our Continuous Monitoring Station has been gathering data around the clock, all year long. Each month, we post information on 10 measures that document water quality at our monitoring site in Yarmouth, near the coastal midpoint of Casco Bay. 

Our Monitoring Station is fondly nicknamed the “Cage of Science” because its high-tech sensors are housed inside a converted lobster trap. These instruments measure temperature, salinity, oxygen, pH, carbon dioxide, and more.

These data help us gain new insights—and new questions–on the health of the Bay. Others are finding these data useful, too. Scientists use our data to inform their own research. Policy makers refer to our data to support legislative action on climate change. Classroom teachers have their students analyze our data to launch discussions on what humans can do to improve water quality. Recently, we discovered that young visitors to the Children’s Museum & Theatre of Maine measure the temperature and salinity of the Museum’s touch tank and compare their readings to our real-world data on Casco Bay.

We have posted our data online for all to see. Visit cascobay.org to see for yourself how Casco Bay is changing month by month.

The news media have recently reported on our plan to expand our array of Continuous Monitoring Stations to get a better understanding of the dynamics of Casco Bay:

Join us! Stormwater impacts and water sampling

August 30, 2023

Want to know how heavy rainfalls, like those we have experienced this summer, impact Casco Bay? Join Friends of Casco Bay staff in South Portland on September 8 at 10 a.m. to learn about the impacts of stormwater on our local waters using both observational and scientific data. What: Stormwater Impacts and Water… Read more

31 Years of Seasonal Sampling

June 8, 2023

Today, on World Ocean Day, we are celebrating our 31st year of collecting seasonal water quality data on the health of Casco Bay! It also happens to be Casco Baykeeper Ivy Frignoca’s birthday – Happy Birthday, Ivy! Every year, from May to October, Ivy and Staff Scientist Mike Doan take… Read more

The Maine Ocean Climate Collaborative Provides a Model to Move Maine Forward

May 11, 2023

Studying changing coastal ecosystems comes with unique challenges – Friends of Casco Bay and our partners are taking them on. Friends of Casco Bay is facilitating the newly formed Maine Ocean Climate Collaborative, a coalition of scientists and marine organizations from the University of New Hampshire to the border of… Read more

Nab Data Suggest Land-Based Sources Contribute to Nitrogen Pollution

April 27, 2023

166 volunteers collected water samples from Portland Harbor to help measure and address nitrogen pollution. Here is what we found. It was a sweltering summer morning on August 7, 2022 when 166 volunteers descended on Portland Harbor to collect water samples for nitrogen analysis. After sending the 178 samples collected… Read more

Mike’s Field Notes: Warm Winter Waters in Casco Bay

April 7, 2023

In this 4 minute video, Staff Scientist Mike Doan breaks down the data from our Continuous Monitoring Station in Yarmouth that show this past winter was unusually warm for Casco Bay. In addition to watching Mike’s video, you can read about these data and the many impacts of warming waters (such… Read more

“Staggering” loss of eelgrass habitat in Casco Bay

March 24, 2023

More than half of the critical and federally protected seagrass meadows in Casco Bay disappeared between 2018-2022. Eelgrass meadows in Casco Bay have declined in size by 54 percent over the past four years, a loss described as “staggering” in a new report from the Maine Department of Environmental Protection (DEP). This… Read more