Bottlenose dolphin deaths have been reported in high numbers all along the east coast of the United States over the past couple of weeks, reports the National Oceanic and Atmospheric Administration (NOAA). A chart comparing the number of stranded dolphins along the coast over the past six years shows 2013 numbers are about four times as high, with the most deaths occurring near Virginia (between 45 and 50 dolphins have been reported as stranded there in July).
NOAA suspects an infectious pathogen, though it will continue to evaluate all possible causes. Preliminary tests of tissues from one dolphin show it may have died of a morvillivirus infection, but it is too soon to say, reports NOAA.
The morvillivirus was determined as the cause of death for more than 750 dolphins that washed ashore along the east coast in 1987. For a long time, the deaths were a mystery, many attributing them to pollution or bacterial algae blooms. In the mid-1990s, however, morvillivirus emerged as the lead suspect.
“The morbillivirus is a relatively new virus that attacks the immune system of an organism. Once the virus has broken into the immune system, it moves into the lymph nodes and respiratory system,” explained Kellie Lewis, Connie Driggers, and Michelle Rothenberg in a 1998 paper titled “Biology of Marine Mammals.”
The virus is a relative of measles in humans.