How an ambitious, three-year-long freshwater mussels project transformed the smelly Manayunk Canal into an emerging fishing destination
Ben Silver reports – “With waders strapped on over PWD polos and khakis, Lance Butler and his team enter the water to place colonies of freshwater mussels in the canal. It’s become a markedly more pleasant experience over the past four years as their work has gradually cleared the water. The PWD calls the introduction of these mussels to the Canal nature-based infrastructure.
Since 2022, Butler’s team has placed approximately 5,000 juvenile mussels into the Canal. Each mussel filters approximately six to 10 gallons of water a day, feeding on algae and bacteria and helping clean the canal. Back when the waterway was dug in 1819, these bivalve mollusks were abundant in the region, but two centuries of industrialism had endangered or entirely extirpated them from their historical range.
Thus, PWD cannot pull from an already abundant stock of mussels; they have to be bred. The aim is to put a million mussels into the canal, which would filter six to 10 million gallons of water per day. They are years away from that goal, but 100,000 mussels are already bred and ready to be implemented.
But Butler and his team don’t expect the mussels to do all the work. Spearheaded by environmental engineer Maria Horowitz, PWD also operates a physical cleanup plan. The Marine Debris and Floatables Program removes trash from the canal weekly. The Manayunk Development Corporation and Friends of the Manayunk Canal help remove debris, too. In 2025, the PWD felt enough progress had been made to be able to gradually open the locks connecting the Canal to the Schuylkill River for the first time in 85 years.
Now, with the mussels working full-time to purify the water, and flow reintroduced from the Schuylkill, the Manayunk Canal looks like a postcard. In the summer, it’s easy to find egrets making their nesting grounds, huge snapping turtles lurk under logs — and, of course, fish.”
Read the full story in the Philadelphia Citizen.
Photo Credit: Philadelphia Citizen