05/20/2026
Help Us Track Cape Cod’s Blue Mussel Story - For decades, blue mussels were one of the most familiar sights on New England’s rocky shores. They formed dense beds along intertidal shorelines, jetties, pilings, and other hard surfaces, creating habitat for small marine life and providing food for fish, birds, and other coastal species.
However, across the region, scientists have documented major declines in wild blue mussel populations over the past several decades. In some places where mussel beds were once thick and widespread, they are now sparse or nearly absent.
Blue mussels are considered a foundation species because they help shape the intertidal community around them. Mussel beds provide shelter for small marine animals, serve as an important food source, and help filter coastal waters.
When mussels disappear, the shoreline community changes with them.
The causes of these declines are complex. Warming air and water temperatures, predation from invasive European green crabs, pollution, storm impacts, and other changing coastal conditions may all play a role. One of the biggest challenges to tracking the decline is understanding where mussels were historically abundant, where they remain today, and where people have noticed changes over time.
To help fill those gaps, the five regions of the MassBays National Estuary Partnership are working together to track blue mussel abundance across Massachusetts. As the MassBays Regional Coordinator for Cape Cod, APCC is gathering both current observations and anecdotal information about blue mussels in our region. We are asking residents, shellfishermen, municipal staff, beach walkers, boaters, fishermen, naturalists, and anyone with knowledge of local shorelines to share what they have seen.
Have you noticed blue mussels in your area? Do you remember places where mussels used to be more common? Have you seen changes along a favorite beach, harbor, jetty, rocky shoreline, or dock?
Please consider taking a brief survey to help us better understand Cape Cod’s blue mussel history and current distribution.
Take the survey! https://survey123.arcgis.com/share/c46d846e258a48b3bbbaf9cf4dce2a0c
Your observations can help provide important local context and guide future monitoring, research, and restoration efforts across Cape Cod and Massachusetts.
