If you’ve walked much along the Hudson’s shores, you’ve probably seen thorny, black water-chestnut seedpods piled up along the high-tide line, thick stands of common reed in wetlands and along the railroad tracks, mute swans gliding across the water, carp splashing in the shallows, chunky shells of Atlantic rangia on the beaches of Haverstraw Bay, and the thin, sharp shells of zebra mussels littering shorelines from Newburgh north.
