Deer populations in the region have increased over several decades. Feehan said many now live in coastal areas, where natural predators are limited and food is readily available. The animals are well adapted to these habitats, but their repeated movement across the same ground can leave marks on fragile landscapes.

On beach cliffs, trails can strip vegetation and create weak points where sections of the edge may break away. In salt marshes, the trails can compact soil and interfere with the natural movement of water, Feehan said.

The deer-related damage is considered a relatively small factor in coastal erosion. Other researchers studying erosion, including on Block Island, have described the impact as minor. Feehan said, however, that deer can have substantial effects on the ecosystems they inhabit, making their influence one concern among multiple pressures on coastal environments.

Massachusetts has expanded hunting opportunities in coastal wildlife management areas as one way to manage the deer population. The state’s Share the Harvest program also lets hunters donate venison to local food pantries. Feehan said the program has been particularly successful on Martha’s Vineyard, where donations can help feed both hunters’ families and other households.

Feehan said public education about less visible effects, such as changes to marsh hydrology and shoreline vegetation, is also important. Coastal ecosystems are already facing multiple stresses, he said, and deer activity can add another.