The bottlenose dolphins are a threatened species. In 2013, more than 1000 bottlenose dolphin deaths due to a measles-like virus have been reported along the eastern seacoast of the United States

The National Oceanic and Atmospheric Administration, which has been investigating the matter, claims the highest number of dolphin deaths have been reported this year. The number has surpassed the highest recorded 740 deaths in 1987-1988, reveals a recent post on The Guardian.

Around 39,206 bottlenose dolphins populated the eastern seaboard in 2010, according to the latest NOAA records. In the last two months, 65 dolphins have been found stranded on Florida beaches coming from Brevard County North.

More than 930 dolphins have been found stranded along the Florida coasts this year, reports news-journalonline.

According to the NOAA officials, the rise in morbillivirus, the measles-like virus, has been the primary cause of death in the dolphins although they are still not clear why there has been a sudden surge in the virus this year. The last such spurt in the morbillivirus was recorded 25 years ago. Some marine experts from NOAA have defined the rise to be natural and cyclical.

"The last occurrence of this was about 25 years ago and the animals that survived that would have natural antibodies. But as those animals slowly die out and new animals are not exposed, they may not have that immunity," said Erin Fougeres, a marine mammal biologist at NOAA, in a statement.

The virus has spread to other marine animals too. Pilot whales have been affected by morbillivirus. Earlier this month, 11 short finned pilot whales were found dead along Florida Keys due to morbillivirus. An earlier study revealed that 93 percent of the stranded long finned pilot whales were found positive for the virus, proving that the virus is widespread among the marine species, reports The Guardian.

 Nearly 803 manatees deaths have been reported in 2013. The toxic algae thriving in the Gulf of Mexico have been found responsible for these deaths, according to state Wildlife Conservation.

 Some scientists opined that global warming and pollution have also played their part in making the species more vulnerable to the virus.  Scientists in the late 1980s estimated that morbillivirus was responsible for killing off nearly 50 percent of the migratory dolphins.