The effects of off-road vehicles (ORVs) on invertebrates inhabiting macrophyte debris (wrack) and supratidal sands on energetic beaches in the northeastern United States were studied at Cape Cod (MA) and Fire Island (NY) National Seashores. the authors focus on the effects of off-road vehicles on the supratidal invertebrates. First, they compare four different wrack-laden beaches in the northeastern U.S. (three within Cape Cod National Seashore, one within Fire Island National Seashore) that have neighboring sections of ORV-traveled and ORV-free beach and second, the authors perform a...