The Cape Needs Its River Herring
Cape Cod News editorial staff
The annual herring run is underway. Find out why river herring are such a big deal for Cape Cod.
"I want people to understand that it's such an important part of Cape Cod's cultural history. People used to go hunting, shell fishing, fishing from the shoreline catching river herring and that feature is somewhat fading at least in some people's memories. Some people just don't have that experience, so they don't appreciate that going out to get these fish was an important part of the Cape Cod experience."
— Brad Chase, Diadromous Fish Project Leader, Division of Marine Fisheries
What is a herring run?
22.APRIL.2025 — CAPE COD, MA — The river herring run is well underway on Cape Cod. River herring—comprising of two species; alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis)—are small, migratory fish with deep ecological significance on Cape Cod. Every spring, these fish return from the Atlantic Ocean to the freshwater rivers and streams of Cape Cod to spawn, a journey known as the herring run. This spectacular migration typically peaks from late March through May and draws attention from locals and nature enthusiasts alike.
In this 12-minute short documentary, Lower Cape TV’s Coast & Climate reporter, Angela McNerney sat down with Brad Chase, the diadromous fish project leader for the Massachusetts Division of Marine Fisheries to discuss these unique fish and their spring dance.
What is the spring migration?
Warming water temperatures trigger the spring migration. Adult river herring respond the the environmental cues and navigate upstream through fish ladders and natural channels to reach their natal spawning grounds in freshwater ponds and lakes. After spawning, the adults return to the ocean, while the young remain in the freshwater systems until they are strong enough to head out to sea in the fall.
Why do river herring matter?
Ecologically, river herring are keystone species in both marine and freshwater food webs. This means they serve as a critical food source for a wide range of predators, including striped bass, osprey, herons, seals, and larger fish like tuna. Additionally, their spawning migrations help cycle ocean nutrients into inland ecosystems, enriching freshwater environments.
On Cape Cod, conservation efforts are underway to restore herring populations, which have declined significantly due to overfishing, habitat loss, and physical barriers to migration. Many local communities and organizations monitor herring runs and work to maintain or restore stream connectivity to support this vital part of the region’s natural heritage.
