VIRGINIA BEACH-It's been a deadly summer for the bottlenose dolphin, especially in Virginia.
VIRGINIA BEACH - More than 100 dolphin corpses have washed ashore in the state, most on the beaches of Hampton Roads and scientists are trying to determine why they're dying.
Virginia has the highest number of dolphin deaths, although strandings and deaths have occurred as far north as New York.
According to NOAA's Website, strandings in the Mid-Atlantic region from early July 2013 in New York, New Jersey, Delaware, Maryland and Virginia were more than seven times the historical average for July.
The deaths are so alarming that NOAA Fisheries has declared an Unusual Mortality Event, defined as a stranding that is unexpected; involves a significant die-off of any marine mammal population and demands immediate response.
Three dolphins died and washed ashore during the last week of July and officials with the Virginia Aquarium Stranding Response Team said most appear to be that of males.
Officials also told 13News Now that the team normally picks up about 100 mammals each year.
An Unusual Mortality Event was declared in the Indian River Lagoon system along the east coast of Florida. NOAA Fisheries officials noted strandings there in July were almost three times the historical average.
NOAA says dolphins of all ages have been affected. Necropsies haven't revealed a unifying pattern, although an infectious pathogen is considered a likely cause.