The Herring River Estuary in Wellfleet and Truro, Massachusetts was an unrestricted tidal marsh until 1909 when civil engineers constructed a dike across the mouth of the river.
Designed to block the flow of ocean tides and salt water, the dike forever changed the river’s ecosystem. Acidic leaching caused fish kills, downstream shellfish beds were closed, and the nursery for economically-important fisheries was choked off.
Because the tides could no longer flush nutrient-rich sediments farther upstream, the marshlands sank by up to three feet. The altered pH and salinity allowed invasive species to take over, further reducing native biodiversity.
The restoration project underway will restore tidal flow in the esturary and result in ecological and social benefits. The video presents the early history of the estuary, what happened following the construction of the dike and the the condition of the river today.