Freshwater Mussels

Volunteer Survey Program

Scientific Studies

News & Reports

Mussel Survey Program

Freshwater mussels are facing an uncertain future in our local waterways.  Once abundant in both numbers and varieties, many freshwater mussel species in the Delaware Estuary are now in danger of extinction.

Streams without mussels are at a serious disadvantage. Mussels provide valuable natural benefits, such as fortifying streambeds against erosion and removing particles and nutrients. This removal can benefit other plants and animals by allowing sunlight to reach river bottoms. Additionally, a single adult mussel can filter up to 20 gallons of water per day. Imagine a healthy population of these filter-feeding powerhouses doing the work of a man-made water treatment plant!

The Partnership for the Delaware Estuary (PDE) needs your help locating streams with mussels, as well as those without mussels. Working with local watershed organizations, volunteer partners play a very important role in helping scientists monitor the health and locations of these threatened animals, and identifying streams in need of mussel restoration.

Training information is being updated – check back soon for more details!
If you are interested in attending a training workshop, or hosting a workshop in your area, please contact Kurt Cheng.

Guidebook: Freshwater Mussels of the Delaware Estuary
Call a friend or two, and head out to the streams to look for mussels! This guidebook will cover safety, survey preparation and technique, how to spot and identify mussels and more.  Use this guide to help fill out your datasheets.

Data Sheets: Download
Print these data sheets and take them along while surveying for mussels to record your data. When you get home, please submit your survey results and photos to the link below. Scientists will use your information to identify mussel populations for future restoration projects. By rebuilding mussel populations throughout the Delaware Estuary region, we aim to restore healthy streams, healthy ecosystems, and clean water for everyone!

Submit: Your Data
Share your data with the mussel data portal! Whether you found mussels or not, your observations are still great data!

Map: Where have volunteers looked so far?
Mussel icons indicate approximate locations of where mussel surveys were performed, not whether freshwater mussels were found there. For more information about where mussels were found, please contact

Disclaimer: Map is updated periodically. Points will not appear immediately after uploading to the portal.

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The Partnership for the Delaware Estuary is a nonprofit dedicated to connecting people, science, and nature for a healthy Delaware River and Bay. The Delaware Estuary is the region's most important cultural, economic, and recreational resource. Animals and people need a healthy Estuary for drinking water, industry, food and fun. You can sign up to receive our newsletter and be the first to know about fun events and volunteer opportunities!


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