Highly venomous olive sea snakes most often "attack" divers during mating season, chasing them and sometimes even biting them, in what might be a case of mistaken identity.

Tuna, historically overfished, are on the road to recovery, but more sharks and rays are now listed as threatened with extinction, according to this month's IUCN Red List Update.

Ninety-six percent of the films included in the study represented sharks as potentially threatening to humans.

One determined diver achieves her dream of going nose-to-nose with an apex predator in its natural habitat. Here’s how you can dive with leopard seals in Antarctica too.

The new jelly was spotted off Rhode Island while the shark was discovered between Antarctica and Africa.

In this edition of Ask a Marine Biologist, Dr. David Shiffman answers a question about what’s still lurking in the deep.

The endangered whale shark is as mysterious as it is enormous. Here’s how you can swim with whale sharks in Mexico.