Friends of Casco Bay has been collecting data on the environmental health of Casco Bay for over 25 years. Volunteers have been a vital part of our work through our Citizen Stewards Program. Below we discuss the details of the Citizen Stewards Program that started in 1992 and continued through the 2017 sampling season. You can read more about the history of our entire Water Quality Monitoring Program or our current science work.
Our Water Quality Monitoring initially was designed to address: How healthy is the Bay? Where are the problem areas?
Spatial, episodic monitoring by volunteers provided a “snapshot” of the environmental health of the Bay. Volunteers measured dissolved oxygen, temperature, salinity, water clarity, and pH (the level of acidity of the water).
Volunteer Citizen Stewards sampled surface waters from shore from April through October
The data were collected by volunteer citizen scientists, whom we trained to rigorous specifications (using a Quality Assurance Project Plan). These stewards used Secchi disks and water quality test kits specifically designed by us as “Casco Bay kits” with the help of LaMotte Company.
After pulling up buckets of seawater at their shoreside sites, volunteers carefully mixed chemicals, titrated, and flocculated, to get measurements for dissolved oxygen, salinity, pH, temperature, and water clarity. They would devote more than an hour at a time to monitor their assigned stations, at appointed times in both the morning and afternoon, on ten Saturdays from April through October.
Their data enabled us to identify when and where we were most likely to find water quality variations throughout the sampling season. These data, along with other staff collected data, helped us address our early questions, “How healthy is the Bay?” and “Where are the most challenged regions of the Bay?”
These data have:
- Provided critically important baseline data; we continue to build on this data set at key sites around the Bay
- Buttressed our advocacy and community outreach to tighten environmental protections for Casco Bay
- Enabled us to create an annual Health Index of the Bay using Citizen Stewards data
- Identified areas where further study is needed
- Showed that the water quality of certain areas of the Bay have consistently remained healthy or challenged:
- Portland Harbor, the New Meadows embayment, and Harraseeket River mouth showed the poorest water quality
How the data have been used
Because the program follows an EPA-approved quality assurance plan and the data is scientifically sound, it is sought-after by other researchers, state officials, and policy makers. For example, our oxygen data has been used to determine the Clean Water Act “grade” that the State assigns to a water body and the amount of pollution that is allowed to be dumped into the state’s coastal waters. Our data convinced the State Legislature to upgrade the water body classifications for parts of Portland Harbor from the lowest grade, SC, to a healthier SB. Our data also helped to increase protection for The Basin, a popular anchorage in Phippsburg, raising its classification from SB to SA, the highest level of water quality protection.
Once an area has been upgraded, state law prohibits anyone from discharging pollutants that would degrade the water quality of that water body. What does that mean for those who swim, fish, and play in the Bay? A pledge to limit pollution from sewage treatment plants, industrial facilities, and other dischargers.
The data collected by our citizen scientists helps provide an appraisal of the overall health of the Bay, summarized in the Casco Bay Health Index. We created the Casco Bay Health Index as a reliable, easy to visualize overview of the health of the Bay that enables us to identify where problems exist. The Health Index allows us to rank the water quality of each site we sample as Good, Fair, or Poor. In problem areas, low oxygen levels, murky water that prevents sunlight from penetrating deep into the water, and rising acidity levels are recipes for troubled waters. We may not be able to identify the causes of these changes, but our monitoring efforts do show where problems lurk.
Why sample twice a day?
Citizen Stewards sampled at 7 a.m. and again at 3 p.m. Sampling twice a day throughout spring, summer, and fall provides a unique opportunity to assess daily fluctuations. Water quality typically changes from a “worst case” to a “best case” scenario as the day progresses. Knowing that helps us better understand the rhythm of the Bay. The water quality tends to be lower in the morning and higher in the afternoon as oxygen levels in the water increase, pH rises.
Throughout the day, microscopic plants called phytoplankton absorb sunlight and photosynthesize, releasing oxygen into the water. At night, the process is reversed; phytoplankton absorb oxygen from the water. Our data shows that water chemistry is clearly impacted by this cycle of photosynthesis and respiration, and the decomposition of phytoplankton.
Some areas of the Bay experience dramatic daily swings in oxygen, and pH. Often these regions, such as narrow embayments in eastern Casco Bay, are where we find substantial crops of phytoplankton thriving in the water column. When these phytoplankton die and decay, the bacteria that break them down consume oxygen from the water, which other marine life needs. At times, the oxygen levels may get so low that it stresses marine organisms and has even led to fish kills.
Decomposition of these marine plants can also release more carbon dioxide, raising the acidity of the sea water. This makes it harder for baby clams and other shellfish to build their protective shells.
Cover photo: Photograph by Kevin Morris
Thank you to all of our Citizen Steward Water Quality Monitoring Program Volunteers!
We’ve had so many wonderful and dedicated Citizen Stewards over the years. If you were ever a Citizen Steward Water Quality Monitoring Program Volunteer with us and you are not listed below, we apologize and ask that you please let us know by calling the office at (207) 799-8574 or emailing keeper [at] cascobay [dot] org.
Carol Lynn Davis
Larry L. Dearborn
Stephen L. Flannery
Eric L. Horne
Peter J. Horne
Mary Ann Leavitt
Timothy V. Payeur
Jasselle K. Payeur
Anne Michalec Payson
Jordi Saint John
Katrina Saint John
Kari Schank Moore
Mary Beth Teas
Anna Marie Thron
Veronica (Nica) Todd
Amy Grant Trefethen
Ellen Van Fleet
John Van Orden
Lisa Willey Critchfield
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… Read more
Pop quiz: Can you figure out which of these photos is of Casco Bay? The correct answer is B—but on any given day or part of the Bay, Casco Bay could look like any of these three pictures. Why does it matter? Water color can be an important indicator of the environmental health… Read more
As you may know, Friends of Casco Bay has joined a worldwide effort to better understand how our waters may be changing—by observing water color. Since we launched our Color by Numbers pilot project three months ago, 178 of you have signed up to measure the color of Casco Bay. The map of Casco Bay… Read more
What signs tell you that spring has arrived? Grass turning green? A robin in your yard? Ospreys returning to their nests? What about huge blooms of phytoplankton in Casco Bay? The chlorophyll fluorescence measurements in the graph above were recorded by our Continuous Monitoring Station, which has been in place… Read more
It may be hard to believe if you have spent any time outside this chilly winter, but spring likely has sprung in the waters of Casco Bay. By January, the lengthening daylight has jumpstarted the growth of phytoplankton, the single-celled plants that are the foundation of the ocean food… Read more
More than 125 volunteers and supporters of Friends of Casco Bay came to the Volunteer Appreciation Celebration on January 23, to recognize those who give their time to monitor the water quality of the Bay, clean up shorelines, stencil storm drains, participate in community outreach events, and serve on its Board.… Read more