MONTEREY, Calif. -

People along the coast in Pacific Grove have been asking where all the seals have gone. According to a new census report, at least a third of the harbor seals along the Monterey Peninsula have disappeared. Marine experts believe the harbor seals are gone because of a dwindling food source and warmer water temperatures. Over the last 18 months, fish have been swimming away to cooler areas of ocean leaving the seals, on the coast to starve. Normally folks could come to the fence line near Hopkins Marine Station and see countless seals, but not anymore.

"It’s sad, because you know so many other earlier generations have seen them like line these up and now it's just really a handful of them,” said Monterey visitor Gem Baltazar.

As water temperatures started to stabilize, seal observers decided to do a survey to see just how many seals are still around.

"The estimate is that there have been 700 in this group. We didn't see them, we saw a couple hundred. So just extrapolating, we've lost approximately 250 adult harbor seals,” said harbor seal observer Thom Akeman.

Researchers suggest the population is now about 450. They said it’s not likely the seals swam elsewhere, because they don’t migrate, but it’s possible many of them have died.

"We are missing some of the harbor seals that I’ve been following for several years. Bobble is one, Lobster, Key Large-o-- who was very famous because she was the first female to give birth at Lovers Point,” said harbor seal observer Kim Akeman.

Seal experts said it is hard to know how many of the missing seals are actually dead, but studies show that at least 40 disappear from the Monterey Peninsula colony each year.

"Particularly for the harbor seals if you come up to this fence you don't want to go above the fence line. They take that as a threat and they will immediately vacate the beach. So we want to control that stress level because they're already dealing with a lot,” said Kim  Akeman.

The census report said that most of the surviving adult seals do look healthier and better fed, but researchers said that could just be survival of the fittest and it’s unclear if the food source is back.