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The Science Survey

We've got the news down to a science!

The Science Survey

We've got the news down to a science!

The Science Survey

Stewards of the Bronx River: How the Bronx River Alliance is Bringing Back Biodiversity

Located in Starlight Park, the Bronx River Alliance has a community-focused approach, which has led to a cleaner and healthier Bronx River.
This is a view inside the shed at the Bronx River House — you can see cars, kayaks, paddles, and more.

Today, the Bronx River Greenway is an eight mile stretch of bike paths, parks, and playgrounds. In the waters nearby, it wouldn’t be shocking to see kayaks paddle by, or, if you’re willing to get a closer look, a truly impressive display of biodiversity in sections of these waters. Fifty years ago, however, this is not the vision that anyone looking at the waters would have seen. This transformation is in major part due to the Bronx River Alliance, a nonprofit organization officially founded in 2001, as well as preceding groups such as the Bronx River Restoration. Their efforts have ensured that the river looks the way that it does today. 

The Bronx River begins in North White Plains, well outside of the New York City limits, and leads its namesake (the Bronx River Parkway) down through Westchester County and into the Bronx. It cuts a path from the county line through the Bronx Zoo and Botanical Gardens, eventually spilling into the East River at Soundview Park. Its 24 miles span suburbs and city, parks both public and private, and an incredibly diverse collection of neighborhoods and communities. 

The river once powered paper, flour, and steam mills (some of which, like the New York Botanical Gardens’ Stone Mill, are still standing today), and in the 1840s became a home to waste and runoff from the New York Central railroad. The river became heavily polluted — an “open sewer,” of sorts, with much of the borough’s garbage and waste dumped into it — in the late 1800s. Construction on the Bronx River Parkway, which runs alongside the river for much of its length also began around this time, and the parkway was opened in 1925 for public use. 

What had been a green space for thousands of New Yorkers, with its open waters and footpaths, instead became heavily polluted, from its freshwaters in the north Bronx and in Westchester to the salty, brackish waters running through the southern section of the river. This continued throughout the first half of the 20th century, leading up to 1971.

In 1971, the Bronx Council on Environmental Equity was formed, followed three years later by the creation of the Bronx River Restoration. Groups such as these began the fight for healthier ecosystems in the Bronx. The Bronx River Restoration focused specifically on the Bronx River. These groups’ commitments to cleaner water, air, and land in the borough came alongside new national legislation surrounding the environment (1972’s Clean Water Act, and the creation of the Environmental Protection Agency in 1970), which paved the way for the sustainability efforts we see today.

The mid-1990s brought about even more organizations dedicated to the health and well-being of these urban ecosystems. Along with new funding for a pedestrian trail along the river, the City Parks Foundation and the New York City Parks Department banded together for the creation of the Bronx River Working Group. This organization in particular stands out for its joint commitments: to both restore the waterway and to educate the community about the ecosystem that they live near. This two-pronged approach has been seen in community gardens across the city and in the restorations of other bodies of water (such as the Gowanus Canal). By bringing the people who live near an ecosystem, and who interact with it, into the fold and ensuring that they know how to care for these natural areas, they are able to find a more realistic, sustainable, and long-term solution.

In 2001, the Bronx River Alliance was created as a part of the Bronx River Working Group. As per their website, the Bronx River Alliance “complete[s] projects by using rigorous science, sound planning and research, and community-driven involvement — all the way from headwaters in Westchester near the Kensico Dam, down to the mouth in Soundview Park in the Bronx.” The Alliance is housed in a new building in Starlight Park, one of the many city parks and green spaces along the river. The Bronx River House, as it is called, was completed in 2020 and was deemed “the greenest building in the South Bronx” for its solar panel-studded design. The inside of the building holds classrooms, office space, and a massive shed, where kayaks, paddles, and other equipment for community programs are housed. 

Like the Bronx River Working Group before it, the Alliance combines both restoration work and community outreach through its projects. Christian Murphy, the Bronx River Alliance’s ecology coordinator, said, “The community helped lay the foundations of the Bronx River Alliance, with community members in the 1970s being the first people to begin pulling garbage out of the river; without them, we would not be here today.” From asking for community feedback and steering on projects to inviting people into the fold through community programming, the Alliance’s current work carries on the legacy of its predecessors. 

Through conservation efforts ranging from pulling trash out of the river (and tracking its quantities) to replacing invasive species with native ones, the Alliance’s work to restore this body of water has had very real and visible impacts. 

We have also successfully restored some critical wetland habitat along the river, with Soundview Park having a 3.5 acre saltmarsh where there used to be a landfill,” Murphy told me, adding, “Thanks to a partnership with the Billion Oyster Project, there is now a 5 acre oyster reef in the mouth of the river, providing shelter for aquatic wildlife and filtering pollution out of the river. Over the years, these efforts have helped to make the Bronx River a place where wildlife can once again survive and thrive. In 2022, we documented the first bald eagle on the river in 30 years, and in 2023 we had two dolphins visit the river!” 

“The Bronx River Alliance’s conservation efforts are the backbone of the organization,” said Murphy, and it’s clear that these efforts are paying off. I got to see the benefits of this conservation work two summers ago while I was collecting data for my Bronx Science biology research project at a few sites along the river. I came across species known to be highly sensitive to pollution (such as various bug larvae) and even found a tadpole in the riverbed, right outside the Bronx Zoo. Oxygen levels were higher than I had anticipated for sites within New York City (and higher than those at many of the other sites I visited outside of the Bronx River), and the support and help that I received from the Bronx River Alliance throughout my project reveals their emphasis on citizen science.

All it takes is a glance at their website to see how community-facing the Bronx River Alliance is. Their volunteer calendar contains numerous events and programs for people to try out, ranging from gardening to park clean ups to oyster bed monitoring. For those who want a more long term investment in the river, there are opportunities for community members to join advisory teams about the future of the river or even to apply for internships. Citizen-collected data is published on their website for public access, allowing anyone easy access to information about the water quality in their community’s  stretch of the Bronx River.

According to Murphy, “The Bronx River Alliance is currently in the process of updating the Bronx River Intermunicipal Watershed Management Plan (or Bronx River Watershed Plan), a guiding document first published in 2010 that outlines priority restoration projects along the Bronx River. The updated Watershed Plan will include new information regarding climate change risks to the watershed and will focus primarily on reducing the risks of flooding and urban heat island effect on watershed communities. 

The Alliance is also working on tracking sewage pollution to individual outfall pipes in Westchester County. “Unlike the sewer system in New York City, the storm drain pipes in Westchester are separated from the sewer system. When the storm drain pipes leak sewage, it is a sign that a pipe has collapsed and is spilling sewage underground, or that someone has illegally connected a sewer pipe to a storm drain. By tracking which pipes are leaking sewage, we can begin to identify where repairs are needed,” Murphy said.

These current projects will provide a roadmap for the future of the Bronx River, ensuring that the successes of the past few decades do not stop now. They will also tackle specific problems and begin to reverse some of the damage done to the river by the people living alongside it, for a more sustainable future. The last question that I asked Murphy was what his favorite part of working at the Bronx River Alliance has been. He said it has been seeing how much nature and biodiversity the Bronx River supports. “Despite being damaged and polluted, the river is filled with biodiversity, from the smallest, sensitive insect species to huge striped bass and American eels. There is always something new to see, and it feels so good to be helping restore this beautiful, rich ecosystem that is thriving right in the heart of the Bronx,” Murphy said.

Despite being damaged and polluted, the river is filled with biodiversity, from the smallest, sensitive insect species to huge striped bass and American eels. There is always something new to see, and it feels so good to be helping restore this beautiful, rich ecosystem that is thriving right in the heart of the Bronx,” said Christian Murphy, the Bronx River Alliance’s ecology coordinator.

About the Contributor
Lily Zufall, Staff Reporter
Lily Zufall is an Editor-in-Chief of ‘The Science Survey.’ To her, the most appealing part of journalistic writing is being able to walk the line between strictly informational writing and creative stories. Her favorite stories have been ones that allow her to explore New York City and do deep dives on small topics that interest her.  She is a part of the track and cross country teams at Bronx Science, and participates in the biology research program. After high school, Lily hopes to pursue something in the environmental sciences, where she is hopefully able to use the writing skills she has learned on staff of ‘The Science Survey’ in conjunction with the other things she will learn.