Volunteers Bag Over 37,000 Pounds of Recycled Oyster Shells in Wellfleet

By Nate Bernitz

All summer, you slurp oysters and we divert the shells from the landfill to towering piles at Wellfleet’s transfer station. Working with enrolled restaurants on the Outer Cape, our shell recycling team picks up shells every day starting Memorial Day weekend. And over the course of four days this April, a team of Mass Oyster volunteers put the shells from 2022 to use in a new and exciting way.

For this year’s growing season (spring to fall), we hatched a plan with our partners at Wellfleet’s Shellfish Department to take a step forward on how recycled oyster shells are used. The Town of Wellfleet has gotten very good over the years at maintaining healthy, sustainable oyster populations in the harbor. To do that, the Town needs a lot of shells, which are spread along the bottom of Wellfleet Harbor to create habitat for new generations of oysters. Every year, the Wellfleet Shellfish Department makes improvements to their process, and this year one of those improvements will entail securing shells in porous bait bags rather than dumping them in strips along the muddy bottom. When mature oysters spawn this summer, these bags of shells will be perfect habitat for swimming oyster larvae to settle and grow on. 

This is a great idea, but entails a lot of work. There’s a tried and true method for bagging oyster shells for this purpose. And for the most part, the team used that method. It starts with using a porous, plastic “bait bag” material that comes as an 8” tube enclosed at either end. To fill those tubes, the team used a 3’ section of 8” PVC pipe with an attached metal funnel, dumping shells through the funnel to fill the bag. It’s a two-person effort to fill a bag.

The team also experimented with another method. Volunteer Mark Howards, a mechanical engineer by training who has taken a leadership role with the project, explains this well. “Concerns about the conventional bag material led us to investigate biodegradable materials. Alternatives have questionable value which is largely unproven in a marine environment. We did want to try it though and it was purchased as a second bagging method – “cultch balls”. These were closed at both ends using twine. The method used 5-gallon buckets with the ends cut out. 

All in all, over 20 hours of volunteer time, not including staff time and preparation, resulted in filling over 350 bags. Mark said “once you figure out the fastest way and get into a rhythm, it becomes a fun way to spend time outdoors and meet new people, not to mention do something good.” 

After placement in the harbor this spring, and after the summer spawning season, there’s another step to the process. The bags will be lifted out of the water and onto a boat, and then after bringing the shells and the baby oysters growing on them to their permanent growing location, cut open and dumped onto the harbor bottom. By that point, the bags will have done their job and this approach ensures the bags don’t become trash in the harbor as they fall apart over time. Stay tuned for that!