Conservation Spotlight: New Jersey

It’s a cool, cloudy day in September. On the banks of the Paulins Kill Tributary in New Jersey, roughly eight people have gathered. They’re high school students and ecologists, retirees and young professionals, and they’ve come from the Delaware Riverkeeper Network, Appalachian Mountain club, and more—some from as far as 200 miles away. Trained on basic mussel biology, conservation status, and snorkel survey techniques by aquatic ecologists, they’re ready to volunteer as community scientists. Wearing wetsuits and carrying underwater cameras, they wade into the river. 

They’re on a mission to document as many pearly mussels as they can find. 

New Jersey: More Than Just the Turnpike 

The Paulins Kill is the largest tributary in New Jersey that drains into the Delaware River. At 41.6 miles long, it’s known for biological diversity, high water quality, and recreation opportunities like fishing, swimming, and hiking. The Paulins Kill’s water quality benefits municipalities, households, and recreation outfitters by providing clean drinking water in addition to outdoors experiences. Because of its extremely clean water, it also provides habitat for a group of threatened species: the freshwater “pearly” mussels. At AMC we believe in our community’s ability to contribute to scientific research that protects critical landscapes for the well-being of people and the outdoors. This study does just that: by documenting mussels, we can measure water quality, which directly impacts people and the land. 

Pearly mussels belong to the Unionidae family, the largest family of freshwater mussels. They require clean water, abundant spawning habitat for reproduction, and disease-free ecosystems to thrive.  

A common misconception is that mussels’ main role in an ecosystem is cleaning the water by filter feeding. While mussels do filter tiny particles out of the waters in which they live, their main ecological role is nutrient cycling — taking nutrients out of the water and then putting different forms back in. Nutrient cycling benefits stream health, supporting clean and diverse waters. 

Mussel Memory 

In 2018, the Columbia River dam, the largest blockage in the Paulins Kill River, was removed by the Nature Conservancy and their partners. Scientists hoped that with the dam removal they’d see more migratory fish return and an increase in the river’s biodiversity. One way to monitor for changes in the river is to track pearly mussel populations, since they’re good indicators for water health and stream recovery.   

The first survey of the Paulins Kill occurred in 2019. While the results were promising, mussels are slow growing and long lived — some species can live for up to 100 years.  “It’s going to be 10, 20, 30 years before we start seeing the pattern in the long-term dynamics or impacts of dam removal,” Silldorff explains. This is why follow-up surveys will be important — they allow scientists to track mussel populations over time and river recovery over a longer period.  

Long-term monitoring isn’t exactly glamorous. But it’s essential to understanding how populations of plants or animals change over time and in response to different environmental factors. We can see population numbers rise or fall and connect those changes to events like dam removals. At AMC, we’ve been long-term monitoring for almost 100 years for things like air and water quality and weather. Community science – carried out by community members and volunteers – are essential to projects like this.  

Stronger Together 

In 2024, AMC’s Director of Conservation Policy Engagement, Mark Zakutansky, reached out to the DRN about funding opportunities available through AMC. Maintaining survey work over time is difficult in large part due to the challenge of finding continuous funding, but AMC’s funds for rivers and waters offered opportunities for research support. A partnership was born. 

With the new AMC-DRN partnership came new opportunities for community scientists. DRN reached out to its network for 2024 survey volunteers, as did AMC’s Delaware Valley Chapter. Volunteers signed up from New York, New Jersey, Pennsylvania, and Delaware — and AMCers showed up in full force. 

“The enthusiasm AMC members brought was incredible,” Silldorff reflects. “This was really motivating for [our volunteers].”  

River Rebound 

On the banks of the Paulins Kill, volunteers emerge from the water and come back to land. Together, they’ve logged over 80 hours of service time and documented over 1,000 mussels. They’re already planning on coming back in another three to five years for the next monitoring survey. It’s too early in the process to see what the mussel trends are, but the community trends are clear: this hands-on, community science approach has connected local residents with the Paulins Kill in a new and more meaningful way, enhancing recreational enjoyment and building appreciation for the tiny pearly mussel. 

The Delaware Riverkeeper Network plans to continue monitoring the Paulins Kill river’s rebound after dam removal, with AMC volunteer help. With federal funding for research so uncertain, it’s more meaningful than ever for readers like you to join AMC and participate in community science. Donating to AMC supports our in-house Research team, whose data is more critical than ever to state and federal agencies advancing water quality and river recreation in the years ahead.