There are fewer grey seals left in the wild than African Elephants, and concerns are growing after an unprecedented number were found dead in Cornwall.
There are only around 350,000 grey seals worldwide, so experts say it's vital they find out why they are dying before it has a long-term impact on the population.
Caz Waddell, marine conservation officer at the Cornwall Wildlife Trust, told Sky News: "We have got large numbers of seals dying on our shores and the real worry is that a lot of these individuals are adults that are breeding, so the impact to the population could be huge."
Finding out what is killing them isn't easy, as the Government doesn't fund post-mortem examinations on seals but storms, pollution or illness could all be possible causes.
Dan Jarvis, from the Cornish Seal Sanctuary, said the deaths have come during the main birthing season, which could mean more are at risk as pups often can't survive if their mothers die.
The public are being asked to report any dead seals that they find to the authorities.