Freshwater Mussels - Volunteer Surveys

Storm drain medallion

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 that benefit other plants and animals. 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 manmade 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: Download Workshop Presentation
Notes from the presenter appear by clicking on the balloon at the top left of each slide. If you are interested in attending a training workshop, or hosting a workshop in your area, send an email here.

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 contact

Find their hiding spots!
Kids gluing down a storm-drain medallion
Kids gluing down a storm-drain medallion
This is not a rock! It's a mussel "butt".

Assemble a team and plot your route.
Disclaimer: Map is updated periodically. Points will not appear immediately after uploading to the portal.