What’s green, microscopic, and makes half of the oxygen we breathe? Phytoplankton, the tiny algae at the base of the food chain, that’s what!
Measurements of chlorophyll — the green pigment that enables plants and algae to photosynthesize — provide an estimate of how much phytoplankton are in our coastal waters.
In this third edition of Mike’s Field Notes, Staff Scientist Mike Doan shares what he sees when he looks at our Continuous Monitoring Station’s most recent chlorophyll data. You can watch the three-minute video below.
In case you missed them, here are links to the first two videos of Mike’s Field Notes:
We were delighted to have more than 80 Friends of the Bay join us for our 30th Anniversary Members Annual Meeting on June 16. As Executive Director Cathy Ramsdell said during the event, we only wish we could have held it in person.
If you missed the event — or if you want to re-watch your favorite parts — we are providing you with links to the following videos:
In this 8 minute video, the Casco Bay region’s Congressional Delegation, including Senators Susan Collins and Angus King and Congresswoman Chellie Pingree, share reflections on what 30 years of Friends of Casco Bay means to them and to our community.
In this 8 minute video, Cathy describes how our work to protect the health of the Bay continues. We may be socially distant from one another right now, but we remain connected to the Bay. Hear how our work continues.
During the Annual Meeting portion of the event, Steve Bushey and Mark Green were elected to their first terms to the Board of Directors, Malcolm Poole was re-elected to his second term, and Joan Benoit Samuelson and Tollef Olson were elected to their third terms. You can find the complete list of our Board of Directors here.
Stay tuned. Soon we will announce how you can take part in our second 30th anniversary event, which will be held in late July.
Thank you for your support over the past 30 years and for joining us on our voyage toward a healthier, more protected Bay in the decades to come.
What is this Cage of Science that Friends of Casco Bay keeps talking about? We invite you to join Staff Scientist Mike Doan out on Casco Bay for a short tour of our Continuous Monitoring Station. In this 2 ½ minute video, Mike shows off the high-tech components of the station and shares why its stream of data is so important to our work.
When we look at our water quality data, we can see that some characteristics of the Bay influence other characteristics. In this example, large phytoplankton blooms have a big impact on the chemistry of Casco Bay.
Ready for some Marine Science 101?
In the graph below, we compare two types of data we collect at our Continuous Monitoring Station: chlorophyll and pH.
We measure chlorophyll to understand how much phytoplankton is in the water. Phytoplankton are microscopic plants that are the base of the food chain. Chlorophyll is the green pigment in phytoplankton (and all plants) that traps the energy of the sun for photosynthesis. Higher levels of chlorophyll indicate an abundance of phytoplankton. Graphs of chlorophyll show when populations of phytoplankton are on the rise and when they crash.
pH is a measure of acidity. The lower the pH, the more acidic the solution. The pH measurement decreases as acidity increases. That is because pH is an inverse measure of the concentration of hydrogen ions in a solution, measured on a scale of 0 to 14. The scale is logarithmic, and each number is an order of magnitude different. For example, a pH of 7 is ten times more acidic than a pH of 8, and one hundred times more acidic than a pH of 9. pH is an abbreviation for “power of hydrogen.” Any solution with a pH lower than 7 has more hydrogen ions than hydroxide ions. Data from our Continuous Monitoring Station show that pH is around 8.0 on average, but changes hourly, daily, and seasonally.
What is this graph telling us?
The graph above compares chlorophyll and pH data from our station. The two lines track the daily means of that data calculated from July 2016 through mid-March 2020.
You can see the variability in both chlorophyll and pH over time, moving from left to right.
When chlorophyll spikes, there is generally an uptick in pH, and then a decrease in pH as chlorophyll levels drop.
Why does this happen?
Whenever carbon dioxide (CO2) is added to water, the water becomes more acidic (pH goes down). The opposite is true as well. Acidity decreases (pH goes up) as CO2 is removed from the water.
When phytoplankton photosynthesize, they convert carbon dioxide (CO2) from the water to carbohydrates and oxygen. This reduces the amount of CO2 in the water, lowering the acidity. The larger the bloom of phytoplankton, and the longer the daylight hours, the lower the acidity (and the higher the pH). Other factors influence pH as well, but the amount of phytoplankton is a primary driver.
As the bloom ends, much of the phytoplankton die and decompose. The process of decomposition releases CO2 to the water and pH levels go down (more acidic water).
Compare changes in chlorophyll and changes in acidity throughout the year here.
It is lonely out on the pier where Staff Scientist Mike Doan is collecting data on the health of Casco Bay — and he is playing it safe, taking his own selfie as seen here.
We are continuing to monitor the health of Casco Bay. Our Continuous Monitoring Station is still collecting data every hour, 24 hours a day, 365 days a year. Mike services the station every two weeks, making sure the equipment is clean and well-calibrated.
Mike has seen some unusual readings over the past few months — a large phytoplankton bloom in December, a smaller one in February, and warmer-than-usual water temperatures in January and February. He is anxious to compare data from March.
“This has been an unusual winter, and I’m curious to see how conditions change as we move into spring,” Mike reflects.
You can take a look at the data on our website. We also encourage you to get out along the Bay — while maintaining social distancing — and record your own observations on your smartphone. You can find out how on our Water Reporter page.
Friends of Casco Bay is creating a $1.5 million fund to be used over the next ten years to understand how Casco Bay is being affected by climate change. We will launch and maintain three oceanographic Continuous Monitoring Stations at three coastal sites around the Bay to collect data on water quality conditions. Communicating those changing conditions to our community is paramount for advocating for policies and actions needed to adapt to and mitigate the effects of climate change. You can read all about this work and the fund to support it here.
What are the signs of spring for you? Chirping chickadees? Street sweeping? Longer daylight? Changing the clocks? (March 8th is the start of Daylight Savings Time!)
The lengthening daylight jumpstarts the growth of phytoplankton, the single-celled plants that are the foundation of the ocean food web. Like plants on land, they respond to increasing sunlight by bursting into bloom.
How can we know what is happening in the ocean? Our Continuous Monitoring Station indicates the abundance of phytoplankton in Casco Bay by measuring chlorophyll fluorescence. Chlorophyll is the green pigment in plants that traps the energy of the sun for photosynthesis.
Our long-term monitoring station, anchored just above the sea floor off Cousins Island in Yarmouth, collects measurements of temperature, salinity, pH, dissolved oxygen, carbon dioxide, and chlorophyll fluorescence, every hour, year-round.
Staff Scientist Mike Doan observes, “Our Continuous Monitoring Station is going into its fifth year of data collection. During the first two springs [2017 and 2018], the chlorophyll levels peaked, as expected, around March, which would be consistent with seasonal phytoplankton bloom cycles. Last year, we experienced a winter bloom that peaked in January, much earlier than we would have expected. So far this winter we have experienced a similar situation, with a moderate bloom over the winter. We are very interested in seeing what the February and March data tell us.”
We update our website each month, so come back often to see if these early blooms continue to occur in Casco Bay, yet another signal that things may be changing in the Bay.
If you are thinking this past January was unusually warm, you would not be wrong. January 2020 was Earth’s warmest January in 141 years of temperature records, according to NOAA’s National Centers for Environmental Information. According to WCSH6 meteorologist Keith Carson, Portland’s average temperature from December 1, 2019, to February 12, 2020, was 30.2 degrees Fahrenheit. So far, 2020 ranks as the 3rd warmest winter on record in Portland and the 6th warmest in Bangor.
Friends of Casco Bay’s Continuous Monitoring Station in Yarmouth confirms that water temperatures in Casco Bay were also especially warm. Our station has been amassing hourly data on the health of the Bay for nearly four years. This graph compares water temperatures from 2016 to date. Staff Scientist Mike Doan says “It is too soon to claim a trend, but the data are concerning. January 2020 water temperatures were on average the warmest we have seen at the station.”
Amid the delights and demands of the Holidays, we pause here to thank you and all our volunteers, donors, and supporters. You play a crucial role in our ability to monitor the environmental health of Casco Bay, engage community members to be good stewards, and protect our coastal waters from pollution. May the serenity of the season find its way into your heart—along with our gratitude!
We look forward to meeting the challenges ahead in the New Year, confident that with the support of Friends like you, we will forge ahead toward a healthier Casco Bay.
Cathy L. Ramsdell, CPA
Did you see our top 10 stories of 2019?
Let’s walk down Memory Lane together to recall our most popular stories of the year, based on your visits to our website and our social media interactions:
You answered the call when Casco Bay needed your voice. We asked our supporters to urge the Maine Legislature’s Committee on Marine Resources to pass a bill to create a Climate Change and Ocean Acidification Commission. Ultimately, our bill was incorporated into the Governor’s comprehensive climate change bill, which passed with strong bipartisan support.
Casco Bay Temperature Extremes Whenever Research Associate Mike Doan is asked, “What were the highest and the lowest water temperatures this year?” he directs folks to our Continuous Monitoring Station data, which document water conditions in the Bay on a daily, monthly, and yearly basis.
Keep pet waste out of the Bay! While we were examining a pollution incident in Cumberland, we came across a pile of dog poop bags at the outfall of a storm drain. When pet lovers toss poop bags into a storm drain, they are not doing the Bay any favors.
We look forward to keeping you updated in the New Year. Our emails will help you stay on top of news about Casco Bay in 2020, including our 30th anniversary celebration on April 29, 2020, at Ocean Gateway in Portland. Mark your calendar and save the date!