RYE , N.H.(CBS) – There is a mystery on New Hampshire’s seacoast.

Dead seals are washing up on the beaches.

There have now been a dozen seals found on three different beaches. Humans are not responsible, but that’s just about the only cause that has been ruled out.

Six seals have been found on Jenness Beach in Rye alone.

Over the last two days the twelve dead seals have been found from Seabrook up to Wallis Sands Beach. The New England Aquarium is leading the investigation and they admit this is very unusual.

Tides have been high and surf has been strong. Experts wonder if it’s just pushing baby seals that died of natural causes onto the shore.