ASSATEAGUE ISLAND, Md.-
Wild horses on Assateague Island are threatening the environment by eating essential grasses, and officials with the National Park Service are mulling options to reduce the horse population.
There are currently 138 horses on the island–too many for the environment to sustain itself, said Jack Kumer, wildlife specialist at the Assateague Island National Seashore.
The horses eat two types of grasses that are essential to the landscape. They enjoy the beach grasses that maintain the structure of sand dunes, which prevent flooding. And their favorite food source is cord grass, or grass in the salt marshes, which is beneficial both for the Chesapeake Bay and for humans living near it, Kumer said.
Salt marsh grasses prevent excess nutrients from seeping into the water. They also provide a nursery for most of the fish and shellfish living in the bay, Kumer told The (Salisbury) Daily Times.
“The fish cannot exist well out here without healthy salt marshes to hide in while young,” he said.
Salt marsh grasses should be about 4 feet high, but most of the grasses on Assateague Island are between 6 and 12 inches because the horses have overgrazed them, Kumer said.
“All the important things the salt marsh should do, it’s not doing,” he said.
The horses are given non-hormonal contraceptives for most of their lives, with mares permitted to have one foal each. But the population continues to grow.
Horses have lived on Virginia’s Chincoteague Island since the mid-1600s, when local farmers brought the animals there in the summer to avoid paying taxes. The horses remained on Chincoteague and were not brought to neighboring Assateague until the early 1960s, when nine domestic mares and several stallions were privately purchased from Chincoteague and brought to Assateague just before it was designated a national park.
The national park started with 28 horses in 1968, and the number has been increasing by about 15 percent a year, Kumer said. The park service began administering birth control to the mares in the 1980s.
“We’re trying to find a balance between keeping the island healthy and the horses healthy,” he said.
The park service is asking for public input before making a decision about what to do. One option would be to physically remove horses from the island. Kumer said there may be sanctuaries that could take horses and care for them for the rest of their lives.
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