The Charles River Conservancy and Northeastern University’s department of civil and environmental engineering, in partnership with Foth, an engineering consulting firm, and the Massachusetts Department of Conservation and Recreation, have announced the installation of a floating research wetland in the Charles River designed to explore an ecological approach to further improve water quality.
Planted with more than 15 native wetland species, this 700-square-foot, human- made island is the first of its kind in the Charles River basin and a model for resiliency projects across the commonwealth. It will be located downstream of the Longfellow Bridge, near the mouth of the Broad Canal.
Born from the Charles River Conservancy’s Charles River Swimming Initiative, this project aims to build on the EPA’s Charles River Initiative and the dedication of governments, environmental groups and nonprofits to improve the Charles River and focus on the growing threat of harmful algal blooms.
“From our Swim Park Feasibility Study and subsequent daily water quality monitoring at North Point Park for two summers, we learned that local bacteria levels have improved to where swimming could be allowed on most days in the summer,” said CRC Executive Director Laura Jasinski. “However, algae blooms, which are fed by rising temperatures and stormwater runoff, can release harmful toxins and are a growing barrier to swimming. To take full advantage of all the Charles River has to offer, we need to address these climate change realities. Climate adaptation pilot projects, like the floating wetland, are an important first step.”
The Charles River floating wetland project continues a multi-year partnership with NU-CEE PhD student Max Rome, who also led the monitoring program at North Point.
“While development along the Charles has fundamentally changed the river’s ecology, there are lessons we can learn from its original state and nature’s inherent resiliency,” said Rome. “This floating wetland project provides an important opportunity to study how the wetland can bolster zooplankton populations, a natural predator of algae.”
Foth has also been a “critically important member” of the project team. The firm has provided pro-bono services along with knowledge of Charles River and marine engineering projects.
“This project has posed some unique design challenges,” said Scott Skuncik. “We are excited to be a part of this important research effort that reflects our company’s commitment to sustainability.”
“The Charles River is an incredible natural resource situated within the heart of the greater Boston metro area offering visitors with a high level of access to state parkland and recreational opportunities,” said department of conservation and recreation commissioner Jim Montgomery. “DCR works closely with stakeholders and organizations, such as the Charles River Conservancy, in an effort to foster strong partnerships and encourage shared stewardship throughout the state parks system.”
“Protecting Massachusetts’ unique natural resources, like the Charles River, is an essential part of the Baker-Polito Administration’s strategy to mitigate and adapt to the impacts of climate change,” said energy and environmental affairs secretary Kathleen Theoharides. “Building meaningful partnerships at the local level to help identify vulnerabilities and develop innovative solutions is critical to our success, and I applaud the Charles River Conservancy for their work on this project, which provides an important model for future adaptation efforts across the commonwealth.”
For the Charles River Conservancy, using the floating wetland to “increase environmental literacy” is fundamental to their mission and one of the main project goals.
“The floating wetland not only provides an opportunity for research but also a focal point for engagement around the river’s ecology. Many people still think of the Charles as dirty. That is no longer true, but we still have work to do,” said Jasinski. “Although some research and activities related to the floating island have been affected by COVID-19, the CRC is continuing to work with partners to provide opportunities to learn about the wetland. “Keep a lookout for a video game created by students at Cambridge Rindge and Latin High School and, hopefully soon, kayak tours.”
In the latest effort to rid the Charles River of its notoriously “dirty water,” conservationists launched an artificial island full of native plants Tuesday afternoon to study whether it could reduce harmful algae blooms.
Members of the Charles River Conservancy, a group that has worked to maintain the river and its parks for decades, have visions of people swimming in the water on a sweltering summer day, or fishing with friends. They dream of restoring the river to pre-development days.
“So many people still think of it as ‘that dirty water,’ and we’ve made a lot of progress,” said Laura Jasinski, executive director of the Charles River Conservancy. “But we still have new challenges.”
Over the course of two years, scientists will study the effect the 700-square-foot floating wetland has on the river’s water quality. The island, home to 15 native wetland species, was launched near the Longfellow Bridge by the mouth of the Broad Canal Tuesday afternoon.
After collecting water samples from North Point Park along the Charles in years past, “we learned that bacteria levels were at a level where you could swim the vast majority of time in summer, but the problem is with algae blooms” in the late summer, Jasinski said.
The algae bloom predicament “is getting worse, and that’s what’s most concerning,” she said. “They’re hard to predict.”
Algae blooms are overgrowths of algae that can produce dangerous toxins. Nutrients in runoff from surrounding impermeable surfaces, such as pavement and roads, combined with high temperatures in the summer, cause the blooms to peak in July and August, Jasinski said.
The theory is that the island could create a home base for tiny organisms that eat the algae.
“What we’re going to study is how it creates a habitat for zooplankton, the natural predator of algae,” she said.
“While development along the Charles has fundamentally changed the river’s ecology, there are lessons we can learn from its original state,” Max Rome, a doctoral student in engineering at Northeastern University who is working on the project, said in a statement.
If researchers discover a noticeable difference in water quality, several islands may be launched in years to come. It’s hard to say what that might look like, but Jasinski imagines one possibility: an area surrounded by islands, allowing for especially clean water and a designated swimming area.
Along with other data collected from the island, “We would like to understand the effect of proximity of the islands. Could you surround a swimming area with these? How many would there need to be?” Jasinski said.
Although it can technically support the weight of humans, the island is not open to the public, she said. Those who want to get a close look can do so from kayaks or the bridge.
On Tuesday afternoon, a team bolted together two dozen large structures off Magazine Beach in Cambridge, assembling an island like a floating puzzle.
“It’s a seven hundred square foot, human-made island, planted with 3,000 native wetland plants that we are about to tow down the river to just past the Longfellow Bridge, where it will be anchored,” said Laura Jasinski, executive director of the Charles River Conservancy.
The floating wetland is part of a research project aimed at improving the water quality by cutting down on toxic blooms of algae called cyanobacteria that have become an annual summer problem in the Charles.
The project will restore a bit of nature to an area of the river that doesn’t feel all that natural now.
“Where this is going to be, it’s a bulkhead or sea wall,” Jasinski said. “So we don’t have a river bank the way we’re used to in that area. So we’re trying to add that back, effectively, to try to boost the food chain and the river to help it be more adaptable to changing conditions.”
Jasinkski rattled off a list of the 22 native plant species planted on the floating island.
“So we have things like Rose mallow and Sweet flag, Swamp milkweed, Seaside goldenrod, Spotted Joe Pye, Monkey flower,” she said. “So lots of lots of fun things.”
Over time, the roots of the plants will penetrate the structure, creating a hydroponic garden. The floating wetland be there for two years as researchers study what happens around those roots.
“This project is all about understanding what we can do from ecological perspective to kind of help create a river that’s healthy and doesn’t have cyanobacteria blooms,” said Northeastern University PhD student Max Rome, who’s leading that research.
Those toxic blooms have become an annual problem in the Charles.
“What we’ve been seeing… is very distinct blooms that last for about seven to 14 days,” Rome said. “And it tends to occur as the water temperature reaches about 25 degrees Celsius, 77 degrees Fahrenheit. And that usually happens in late July or August.”
Rome says one way to fight cyanobacteria is by cutting pollution.
“But we think another piece that might be important is to add habitat that can help the river support higher population of the creatures that eat algae.”
Those creatures are called zooplankton. Rome will track if the floating island results in more and larger zooplankton around the roots of the plants that grow down into the river.
“It’s going answer some really fundamental questions for us about how the ecosystem changes around the floating wetland,” Rome said. “And then with that data, we’re going to be able to do some modeling and do some estimation to see at what scale could floating wetlands or restored shoreline really make an impact in terms of cleaning up the Charles River.”
Jasinski says the cyanobacteria outbreaks are only expected to get worse as temperatures rise.
“The reason we’re seeing the increased algae blooms in the river is a symptom of the rising temperatures of climate change,” she said. “So we’re looking [at this project] as an intervention to help treat that.”
And she says she hopes as people see the island, it will serve as a way to engage people in those issues.
“We really want to use this as a platform to talk to people about how polluted [the Charles River] was, how far we’ve come, but also the increasing challenges we’re seeing with climate change, rising temperatures, increased heavy rainfall that is still posing a threat to the river that we need to continue to innovate and try to protect.”
The Charles River Conservancy hopes to install a “floating wetlands” at North Point Park next spring to test whether the reintroduction of wetlands to the Charles River basin could shield enough microscopic animals to eat and so control the bacteria that now sometimes turn that stretch of river into a hazard to both man and beast.
Working with Northeastern PhD candidate Max Rome and the Penelope Taylor Studio, the group would install a roughly 700-square-foot floating platform to plant a variety of wetlands plants to determine whether that could be used to shield zooplankton from the fish that have been increasingly drawn to the Charles as its water quality improves.
The floating wetland will be planted with over 20 native wetland species. Plants like rose mallow, cardinal flower, and milkweed will be arranged to create a unique floating garden, an attraction for human and non-human visitors. Throughout our study, we will monitor the plants to understand which species succeed in this novel environment.
If it works, the zooplankton in turn could begin to devour the cyanobacteria, also known as blue-green algae, that now can explode in numbers, creating toxic blooms that can kill dogs that swim in the river and make people sick.
The small platform itself would have no noticeable effect on the overall basin, the group says, but proof of its success could be the impetus to install far more of the platforms – or to plant more permanent wetlands vegetation in what has long been more of a lake than a river, one that, despite clean-up efforts over recent decades, remains chock full of the phosphorus that encourages the growth of the bacteria.