The number of mysterious dolphin deaths has increased to more than 160.



Media outlets report additional dolphins were found along Virginia's coast on Monday. That put the deaths in August at more than 70 - more than the annual average.



The Virginia Aquarium & Marine Science Center reports that 25 dolphin corpses were recovered on Friday and Saturday. Stranded dolphins are turning up in other states on the East Coast.



It's the deadliest period for the sea mammals since a virus killed off more than 700 in the late 1980s.



Scientists are struggling to find the cause of the deaths. It isn't clear whether an infectious disease is causing the deaths, but scientists are warning those who find a stranded dolphin to stay away from it and contact authorities.