Scientists are left baffled as the number of bottlenose dolphin deaths along US East Coast increases dramatically and they cannot pinpoint the cause.

The number of dolphins washing ashore dead or dying along the U.S. East Coast has been above average in the last few months, leaving marine scientists worried and a little baffled. According to a Press of Atlantic City report, about 21 bottlenose dolphin carcasses have been found along the beaches since July 9.

The local news station WAVY reported the discovery of another dead dolphin washed up in the Ocean View area near Norfolk along the state's southeast coast, Wednesday. This new discovery was the third dead cetacean to be found in a matter of days and the fourth in the last three weeks.

Initially, The Virginia Aquarium & Marine Science Center refused to admit that the deaths of these dolphins could be connected. However, in light of recent events, they have reconsidered.

"We are a little bit concerned about it," the Virginia Aquarium's Mark Swingle told WAVY. "It's definitely at a much higher level than we're used to seeing at this time of year."

Associated Press reported that the state Division of Fish and Wildlife, which is working with the Marine Mammal Stranding Center has ruled out poor quality of water as being the cause of death, saying their demise could be a part of the natural disease cycle. Necropsies confirmed that four of the dolphin deaths were caused due to pneumonia.

The Virginia Aquarium released a press statement wherein they confirmed that there have already been 82 dolphin strandings reported this year in Virginia alone. This is notably more than the average 64 reported every year. What's even more disturbing is that nearly half of the 82 dolphin deaths have taken place in July alone, this year.

According to the Press of Atlantic City, the NOAA said last week that it was investigating an increase in bottlenose dolphin deaths between New Jersey and Virginia.

"We're trying to collect any info we can to see if there are any trends," Maggie Mooney-Seus, spokeswoman for the NOAA's National Marine Fisheries Service, told the Press of Atlantic City. "Right now we don't have enough info to say we're seeing anything out of the ordinary. We're still collecting the data."