Home » Science » Continuous Monitoring Station

Category: Continuous Monitoring Station

Donate to Climate Change and Casco Bay Fund

We are 91% of our way to our $1.5 million goal! Help us go over the top!
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

 

Keeping up with the Casco Baykeeper

For Casco Baykeeper Ivy Frignoca, the summer has been full of moments of concern and moments of magic.


How was your summer?

Summer means being on the Bay! Staff Scientist Mike Doan and I continued to collect our seasonal data on the health of Casco Bay by land and sea. As we collected water quality data, we had the opportunity to speak with people who rely on the Bay for their livelihoods and deepened our conversations about what we were seeing and how to use our data to shape our advocacy work.

How did the pandemic affect your Baykeeping work this summer?

We kept up with water quality monitoring by limiting crew on our Baykeeper boat, R/V Joseph E. Payne, to just two of us at any one time. We continued to collect hourly data from our Continuous Monitoring Station. We kept up with all water quality monitoring, including responding to the unexpected.

What changed and what we really missed was inviting others out on the boat with us. We love using the boat as our summer office, a way to gather people who can work together to find solutions to problems that impair the health of the Bay. It makes a big difference to view issues from the water and have people aboard with expertise and authority to address problems. We couldn’t do that this year.

What was the most concerning issue you saw this summer?

What stands out was a day in mid-July when we saw a large area of brownish water extending from the mouth of the Royal River. Mike and I thought it might be a phytoplankton bloom. But when we put our sonde in the water, it measured low salinity levels that were startling, extending out almost to Moshier Island. We had captured a stormwater plume from a recent major rainstorm.

What also stands out was how uniformly high water temperatures remained this summer. Broad Cove saw temperatures near 20°C [70°F] and the upper New Meadows River had temperatures between 25-26.5°C [nearly 80°F].

What we saw this summer reaffirmed for me the urgency of our collective work to document change, reduce the causes of climate change, and prepare for its consequences at community, regional, state and national levels.

How about some of your favorite moments of the summer?

There are always moments of astounding beauty on the Bay. Every day on Casco Bay is magical. Watching terns feeding, bald eagles soaring above the boat, leaping sturgeons in a school of bait fish, or the sunlight reflecting like a mirror on the water are moments of magic that underlie why we work to protect this amazing place.

I really enjoyed becoming more deeply connected to our volunteer Water Reporters. Their posts track important issues and give us a great view of what is happening around the Bay. Working with Community Engagement Coordinator Sarah Lyman, I spent some socially-distanced time with Water Reporters, following up with them as they tracked algae blooms, marsh conditions, reported pollution, and posted about other changes they were seeing in the Bay. It’s awesome knowing that there is a whole team of people in the community helping with our Baykeeping work.

How rainstorms affect the Bay

Today’s rain reminds us that heavy rainstorms can deliver a significant insult to the health of Casco Bay.

Rainwater runoff resulting from intense storms flows into the Bay, bringing with it a host of pollutants including nitrogen, pesticides, oil, and heavy metals. If rainfall is heavy enough, the large dose of freshwater can temporarily lower the salinity, or saltiness, of the Bay.

This year we experienced a long stretch of dry weather through May and into June, which was followed by almost three inches of rain in just two days in late June. This combination created conditions that brought a large amount of freshwater into the Bay through both runoff and increased river flow. The river flow increase can be seen in the United States Geological Survey river gauge data from the Royal River. The Royal empties into Casco Bay near our Continuous Monitoring Station.

The graph above compares the flow of water in the Royal to the salinity at our Station in Yarmouth. The increase in fresh water following the storm causes a decrease in salinity at the station. It takes significant amounts of freshwater to dilute the water in the Bay. This suggests large amounts of stormwater runoff deliver pollutants to the Bay.

The increased river flow was still visible into mid-July. While out conducting our Seasonal Water Quality Monitoring on July 15, Staff Scientist Mike Doan and Casco Baykeeper Ivy Frignoca measured salinity values of 6.4 parts per thousand (ppt) at the mouth of the river where values are typically around 29.0 or 30.0 ppt. As they moved away from the river mouth and out toward deeper water, values were still lower than usual at 12 to 15 ppt.

In the period of time following the storm, we saw a dramatic increase in blooms of nuisance algae. This is potentially the result of increased nutrients in the stormwater runoff, as well as high water temperatures.

As Casco Bay continues to get warmer and we experience more frequent and intense rain storms because of climate change, we may see more pollutants and more nuisance algal blooms in the Bay.

This is one of the many reasons why Friends of Casco Bay launched the Climate Change and Casco Bay Fund, which will help us put two more Continuous Monitoring Stations in the Bay, one near Portland and one near Harpswell, and operate all three stations for ten years. The $1.5 million Climate Change and Casco Bay Fund will be used over the next decade to understand the ways in which our waters are changing, while we engage the community in assessing and adapting to climate change. You can read more about the Fund and our 10-year plan here.

What can you do about stormwater pollution?

  • Did you know that the fertilizers and pesticides you put on your lawn may end up in Casco Bay and contribute to these problems?
  • Keep pollutants from entering the Bay by reducing or eliminating the fertilizers and pesticides you apply to your lawn.
  • Become a Water Reporter. Our volunteer observing network tracks the spread of algal blooms around Casco Bay. We use that information to alert the State to changes in our coastal waters.
  • Make a donation to support the Climate Change and Casco Bay Fund.

Casco Bay is heating up

Seem hotter than usual? Yes, indeed.

Our Continuous Monitoring Station has been collecting hourly data on the health of the Bay for more than four years.

Data from the station show that this summer has been the hottest one we have recorded since our “Cage of Science” has been in the water.

This graph compares water temperatures from 2016 to this month. The lavender-colored line represents the daily averages for this year.

Staff Scientist Mike Doan says “The data are concerning. This summer’s temperatures were on average the warmest we have seen at the station.”

You can find the most recent data for all the parameters we measure at our Cage of Science here.

In addition to collecting hourly data, for nearly 30 years, we have been spot-checking sites in the Bay. The temperature data from our three Sentinel Sites (see graph below for annual average, data collected May through October each year) show an upward trend as temperatures in Casco Bay have risen by 2.4° Fahrenheit [1.3° Celsius].

annual temperatures graph 2019

“Casco Bay is changing and changing quickly,” reports Executive Director Cathy Ramsdell. “That’s why we have launched the Climate Change and Casco Bay Fund, which will help us put two more Continuous Monitoring Stations in the water, one near Portland and one near Harpswell, and operate all three stations for ten years.”

The $1.5 million Climate Change and Casco Bay Fund will be used over the next decade to understand the ways in which our waters are changing, while we engage the community in assessing and adapting to climate change. Friends of Casco Bay has raised 87% of its goal for the Fund. You can read more about the Fund, our 10-year plan, and make a secure donation here.

What’s green, microscopic, and makes ½ our oxygen?

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:

Mike gives a tour of our Continuous Monitoring Station.

Mike discusses how warm our winter and spring have been.

30 years of success protecting the Bay

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.

Lastly, and perhaps most importantly, in this video Cathy shares our plans over the next decade and beyond to help our community address looming threats, and she announces the formation of the Climate Change and Casco Bay Fund for Technology, Science, and Community Engagement.

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.

Take a tour of our Cage of Science

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.

Boom and Bust: How phytoplankton influence pH

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.

This image of phytoplankton is courtesy of Southern Maine Community College.

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.

We’re still monitoring the health of Casco Bay, and you can too

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.