BRIGANTINE - Bottlenose dolphins have been washing up on the Jersey Shore in alarming numbers over the last few weeks.

Officials at the Marine Mammal Stranding Center say 21 dolphins have washed up in areas from Sandy Hook to Cape May. "It's pretty upsetting, and we don't know why, and we're trying to stop it," says volunteer Christina Price.

The founding director of the center says they've had so many dolphin deaths that they've run out of body bags and sometimes have no space in their refrigeration unit.

So far, four dolphins have tested positive for viral pneumonia, one carrying morbillivirus, which spreads like the measles. "One exhales with the virus, and one swimming behind it inhales and ends up contracting the virus," according to Bob Schoelkopf with the Stranding Center.

The experts say that anyone who finds a dead dolphin or one that appears sick should stay away because the distressed animals could attract sharks.

Authorities won't know what caused the death of the remaining dolphins until they get test results.

The Department of Environmental Protection says the deaths appear to be part of a natural disease cycle and not related to water quality.