The father, 51, and son, 24, were snorkeling at Port Kennedy near Perth in Western Australia, the Australian Broadcasting Corp. reported. The beach was closed and volunteer search teams and about 10 boats joined the search for the missing man.

The family of the presumed victim asked that the shark not be killed if it is located.

The man was described as a bank employee and enthusiastic swimmer who often visits the beach in Port Kennedy. He was about 20 feet from the beach when his son, some distance away, heard thrashing and saw blood in the water.

Police asked the public to avoid the beach where the attack occurred and advised people to be careful at other beaches.