Development has stripped away forested buffers from the banks of streams and rivers. Trees and plants that grow along streams create a natural buffer that captures pollution and prevents erosion. They also provide shade over streams, which is vital for species like sea-run brook trout that can only spawn in clear, cold water. Nearly one-third of the Buzzards Bay watershed’s stream buffers have been lost to development. Without healthy forested buffers to protect our streams, polluted stormwater runoff from roads and parking lots rushes into nearby streams and destroys spawning habitat for fish.

Dams, road culverts, and other obstructions block nearly all of Buzzards Bay’s major rivers and small streams. These man-made structures alter the natural flow of our streams and rivers. People started building dams on rivers in the 1700s to power mills. But after the mills disappeared, the dams remained. And as transportation expanded throughout the region, culverts were installed so water could pass under roads built across streams. In other areas, streambanks have been channeled through cranberry bogs or hardened with concrete, creating even more problems.

In short, many of the Bay’s streams and rivers are broken. As a result, the Bay’s migratory fish are suffering, which has negative effects throughout the Bay ecosystem. River herring and other migratory fish have a hard time swimming past tall dams, dark culverts, and narrow channels to reach their freshwater spawning grounds. Fish ladders have been installed at many dams, but they’re rarely successful. If river herring can’t reach their spawning areas, they’re much less likely to reproduce.

Dams and blockages are one of the biggest problems facing river herring, eels, and other migratory fish. Only a tiny fraction of the historic populations of herring still make the journey upstream each spring. For instance, herring populations in the Mattapoisett River dropped from 1.85 million fish in 1921 to under 20,000 in recent years, representing less than one percent of their historic high. Some species that used to be abundant here, such as shad, sturgeon, and Atlantic salmon, are entirely gone.

Salt marshes are key to coastal ecology and provide resilience to weather events such as storm surges. Low elevation marshes are susceptible to drowning with sea level rise and structures that obstruct natural tidal flow to the marshes. They do not need to be underwater entirely to be affected by sea level rise. Their health is affected by higher tides and occasional storm tides that leave more salt water on its surface. In the short-term, the Coalition is employing runnels to drain sea water to keep it from pooling on the marsh surfaces. To adapt to sea level rise in the long-term, marshes will need to migrate landward.