Centuries of development and industrialization have reshaped and impaired our region’s harbor and estuaries. In recent years, progress has been made protecting these intricate and fragile ecosystems, but sea-level rise and more frequent storms threaten to erase these gains—and in fact, further disrupt them. Restoring wetlands, nurturing oyster beds, and providing pathways for migration of habitat as sea levels rise will ensure the harbor and the region’s estuaries remain essential economic, ecological, and recreational resources.