Category: Continuous Monitoring Station

November 13, 2018

Water Temperatures Are Changing in Casco Bay

Our CMS allows us to identify nuances in how the Bay is changing year-to-year in far more detail than we ever could before.

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.

August 24, 2018

See sea critters and our Cage of Science

Watch this short video about the Cage of Science!

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.

Thanks to support from Casco Bay Estuary Partnership and generous donors, our Continuous Monitoring Station collects data once an hour, every hour, year round.

June 26, 2018

Spring Blooms in Casco Bay

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 for almost two years.

Chlorophyll fluorescence is a measure that provides an estimate of phytoplankton abundance. Chlorophyll is the green pigment in plants that traps the energy of the sun for photosynthesis.

The graph tells us that this year’s spring bloom of phytoplankton started around the same time as last year, but was bigger in magnitude this year than in 2017.

Why do we care about chlorophyll levels? Phytoplankton are the single-celled plants that make up the foundation of the ocean food web. Phytoplankton also provide half of all the oxygen we breath—so thank phytoplankton for every other breathe you take. You can read more about phytoplankton and chlorophyll in our recent post.

Photography by Kevin Morris

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.

February 15, 2018

Spring starts early in Casco Bay!

Our Continuous Monitoring Station chronicles the rise and fall of microscopic blooms in Casco Bay. This graph of chlorophyll fluorescence tells us that the spring bloom of phytoplankton beneath the ocean happens well before plants on land emerge from beneath the snow.

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 web. Like plants on land, they respond to increasing sunlight by bursting into bloom. By mid-February, daylight has increased by over an hour since December 21st, and the phytoplankton are flourishing.

Last January, 2017, there was an early bloom of phytoplankton in Casco Bay. How do we know? Friends of Casco Bay maintains an underwater sentinel that collects information about the water of the Bay every hour, 24 hours a day, 365 days a year. It is our Continuous Monitoring Station.

We will soon be crunching the January-February 2018 data, looking for confirmation of this year’s phytoplankton bloom.

A modified lobster trap houses a carbon dioxide sensor and a data sonde, electronic devices that continually take the pulse of the Bay. Together, they provide evidence of how our coastal waters may be changing over time. This long-term monitoring station, fondly known as “the Cage of Science,” is anchored just above the sea floor off Cousins Island in Yarmouth.

We now have over a year of hourly data on oxygen levels, carbon dioxide, pH (the level of acidity of the water), salinity, temperature, water clarity, water depth, and chlorophyll fluorescence, a measure that provides an estimate of phytoplankton abundance. Chlorophyll is the green pigment in plants that traps the energy of the sun for photosynthesis.

Phytoplankton provide food for the smallest zooplankton. These tiny floating animals are eaten by larger zooplankton, such as copepods, shrimplike creatures. Both phytoplankton and zooplankton are at the mercy of the currents, winds, and tides.

The data from the Continuous Monitoring Station documents the changes in the water’s chemistry as a result of these blooms. The net positive effect in Casco Bay over the course of the spring season is more oxygen and less acidic water, thanks to those early-blooming phytoplankton.

Beyond Casco Bay, in the Gulf of Maine, a circular current called a gyre distributes marine life around the Gulf. The gyre transports phytoplankton to where zooplankton are hatching, just in time to feed emerging copepods, which in turn feed baby fish, clams, and other sea creatures.

Success in the ocean food web, like in much of life, depends on being in the right place at the right time.

Our Continuous Monitoring Station has been in place for about a year and a half, too soon perhaps to provide data that might indicate whether or not Casco Bay’s food web is changing. Still, every hour and every day, our cage of science is building a more complete picture of the seasons beneath the Bay, giving us insight into how climate change may alter the food web of our coastal water in years to come.

Thank you to funders of this project, including Casco Bay Estuary Partnership, Davis Conservation Foundation, Horizon Foundation, Schwartz Family Fund of the New Hampshire Charitable Foundation, and WEX. We also thank our Members and the many donors, local businesses, and foundations that give us operational support to do our work each year.

October 12, 2017

Monitoring a Changing Casco Bay 365 Days a Year

When we haul up the Continuous Monitoring Station to download data and recalibrate the equipment, we also track marine creatures that may have found a home on our “cage of science.”

Covered with sea squirts, sea stars, and other marine hitchhikers, the newest member of our monitoring team looks like an abandoned lobster trap. It may be homely, but we are pretty impressed with what it does, collecting water quality data hourly, 24 hours a day, 365 days a year. It is our Continuous Monitoring Station, which will help us answer the question “How are our coastal waters changing over time?” Research Associate Mike Doan calls it “the cage of science.”

It has been just over a year since we placed a carbon dioxide sensor and a data sonde—an electronic device that records temperature, pH, and other characteristics of water quality—inside this modified lobster trap and moored it in healthy waters near the center of Casco Bay off Cousins Island in Yarmouth.

After one full year, we have over 8,760 hours of data on oxygen levels, carbon dioxide, pH (the level of acidity of the water), salinity, temperature, chlorophyll fluorescence (estimated phytoplankton abundance), water clarity, and water depth.

Thanks to our 26-year data set on water quality in Casco Bay, we understand when and which areas of the Bay are likely to exhibit challenged water quality conditions that require further study. Armed with this baseline data, we can now consider how to address the question, How is the Bay changing?

The steady flow of data from the Station already is helping us detect and document how climate change and emerging coastal stressors may be affecting the Bay. Hourly data helps us identify daily, seasonal,
and annual trends to better understand the extent to which ocean acidification may be impacting the water chemistry of Casco Bay. In future years, we hope to deploy two more “cages of science,” one in challenged waters in Portland Harbor and one near Harpswell to help detect the influence the Kennebec River has on Eastern Casco Bay.

What is a data sonde?
A data sonde, such as the one being used by Research Associate Mike Doan, is an oceanographic
monitoring instrument that takes multiple measurements of water quality simultaneously. In
addition to being used as part of our Continuous Monitoring Station, data sondes are used by
staff scientists in other water quality monitoring efforts from shore and by boat. The data is
downloaded to a computer and analyzed to provide a long-term picture of water quality over
time. We thank Casco Bay Estuary Partnership and our generous members for helping fund
our Continuous Monitoring Station’s first year.

January 20, 2017

Keeping an eye on the Bay 24/7

Imagine working 8,760 hours a year. Friends of Casco Bay has two water quality monitors that do just that: a datasonde, an instrument that can measure several properties of water at once, and a specialized device that only measures carbon dioxide. They are anchored together on the ocean floor in Yarmouth to collect data once an hour, every hour, year round. Appropriately, these high tech tools comprise our new Continuous Monitoring Station. These hard workers have been in place since July 2016.

Why is this hourly data vital?

The steady flow of data our Continuous Monitoring Station collects will help us detect and document how climate change and other emerging coastal stressors may (or may not) be affecting the Bay. Hourly data will help us identify daily, seasonal, and annual trends and better understand the extent to which ocean acidification may be impacting the water chemistry of Casco Bay. The station may also help us assess sea level rise. The station collects data on oxygen levels, carbon dioxide (CO₂), pH (the level of acidity of the water), salinity, temperature, chlorophyll, and water depth.

In order to ensure continuous data, we have two datasondes which are swapped and refreshed every two weeks. When he arrives at the dock in Yarmouth, Research Associate Mike Doan has less than an hour to reposition the alternate datasonde so that we don’t miss any of those 8,760 hours of information.

Mike hauls up the anchored devices, uploads data from the CO₂ sensor to his laptop, and scrapes off marine hitchhikers such as sea stars, tunicates, and algae. “It’s amazing how fast sea creatures occupy any available surface, including our instruments!” says Mike. Before he leaves, he replaces the datasonde with one freshly calibrated and lowers the entire Continuous Monitoring Station back onto the ocean floor. Such attention to detail provides quality assurance that the data is accurate.

While this station is busy year around, we continue to enlist volunteers to help us understand the overall health of our marine waters and to identify troubled areas of the Bay. From April to October each year, more than 90 volunteer Citizen Stewards monitor scores of shoreside sites where they measure five parameters of the surface water: pH, salinity, water temperature, water clarity, and oxygen level. If you are interested in becoming a water quality monitoring volunteer, you can learn more about the program here.

Our volunteers, staff scientists, and now our automated partners, all play a role in helping us to better understand what is going on in Casco Bay.

August 9, 2016

A New Tool Trending in Casco Bay

Many people get excited about bringing home a new electronic gizmo, like a smartphone, a hoverboard, or a drone. Acquiring one of these gadgets couldn’t match the excitement here when UPS recently delivered a new, high-tech, scientific instrument to Friends of Casco Bay.

Research Associate Mike Doan gleefully unwrapped our new water quality monitoring tool— a “partial pressure CO₂ sensor”—an electronic device that can measure carbon dioxide in seawater.

This new sensor has been deployed next to our data sonde which measures pH (acidity), salinity, temperature, chlorophyll, and oxygen. Both instruments will collect data hourly, year-round, for decades to come. The carbon dioxide data, in conjunction with pH readings, will help us better understand the dynamics of coastal acidification here in Casco Bay.

Our water quality monitoring program was created over 25 years ago to collect data on the health of Casco Bay waters, with transects across the Bay by staff scientists monthly, and data collected by citizen scientists at dozens of shoreside sites on ten selected Saturdays. Those valuable data provide snapshots of the health of the Bay and alert us to trouble spots.

With climate change influencing weather and waters around the world, we felt the need for a stream of data that would allow us to ask deeper questions. With our new tools, we are now able to collect more frequent, real-time data that will help to identify trends in the chemistry of Casco Bay. Having more data on nitrogen and carbon dioxide, both of which impact the acidity of our coastal waters, will aid not only our advocacy and education, but also the work of other scientists, government officials, and activists working to protect Casco Bay.

We chose to anchor our first comprehensive, continuous monitoring station in Yarmouth. We are thinking of naming this new fixture in the bay Kolpos, which is Greek for bay. Purchase of this high-tech addition to our water quality monitoring program was made possible by Casco Bay Estuary Partnership, the Horizon Foundation, and the generous support of our members. As funding allows, we will place additional stations in Portland Harbor at the western end of the Bay and Harpswell in the eastern end.

And, as always, we will continue to rely on the data that our staff and volunteers collect, as we have since our water quality monitoring program began more than 25 years ago.