In those areas, the normally tough grass that prevents beach erosion is now brown and limp. Old Orchard Beach has lost about 25 percent of the grass it planted 20 years ago after rebuilding eroded dunes, The loss of sea grass is perplexing scientists all along the Eastern seaboard. In Maine, dune grass is concentrated in the southern part of the state, where most of the sandy beaches are. Some researchers believe that an elusive disease is killing the grass, which may have been weakened by prolonged lack of rain in the late 1990s. But no definitive cause has been found, Whiting-Grant said.
Dunes are subject to a high degree of erosion because they lie directly in the path of the tides.
Dunes depend on plant growth such as dune grass for their stability. Destruction of dune grasses prompts extensive wind and water erosion. Thirty years ago, people were allowed to build along the shore, and as more people moved closer to the beaches, many towns plowed the dunes to create more space for sunbathers. Parker Dwelley, a 30-year resident of Goose Rocks Beach in Kennebunkport, said the curious thing is that the grass in some portions of the beach is healthier than at others. At the west end of the beach, for instance, the grass has had the most trouble surviving.