VA BEACH – Dolphins continue to come ashore on Virginia and North Carolina beaches, but marine experts still don’t know what’s causing the strandings.

SLIDESHOW: Stranded dolphins

Joan Barns with the Virginia Aquarium says two adult male common dolphins stranded on the Eastern Shore last week on either side of Assateague Island.

Additionally, two live common dolphins stranded on the Outer Banks.  One died and the other disappeared in the surf.

Those strandings come two weeks after seven dolphins were found over several days – at Back Bay National Wildlife Refuge and on the Eastern Shore.

“There are still no commonalities to the deaths and we are waiting for results of additional analyses,” Barns stated.