The seal on the Mount Main Beach yesterday is a Leopard Seal, a dangerous marine predator known to have attacked and killed humans.

The DOC signs warning people to stay away 20 metres were being ignored and lifeguard Kent Jarman says he was blown away by how close people including young children were getting to the leopard seal.

Leopard seal on the Main Beach Photo: John van den Broek

'DOC had placed two signs about 3 metres away saying keep 20 metres away, but of course everyone stood where the signs were. I stopped two young women who looked like they wanted to give it a pat,” says Kent in a facebook post.

Leopard seals eat almost anything; krill, penguins, fish, seals, cephalopods; octopus, squid, cuttlefish – and they have been known to attack humans. A diver was killed by one in Antarctica in 2003.

The DOC website says leopard seals are the only seals known to regularly hunt and kill warm-blooded prey, including other seals.

Large adults have attacked humans. It's likely they are opportunistic in they prey on whatever is readily available.

Leopard seals are easily identified by the long slim body and comparatively large fore-flippers.

The disproportionately large head, massive jaws, impressive teeth and tremendous gape give a distinctive look to a marine predator only bothered by orca.

Leopard seals are usually solitary animals. Males are sexually mature at 3-6 years of age and females at 2-7 years. Mating has never been observed in the wild.

Another leopard seal stayed at the Tauranga Bridge Marina in January. Leopard seals are protected under the Wildlife Act and the Marine Mammals Act. DOC is mandated with the leopard seal's protection.

The Tauranga Bridge Marina Leopard seal shows teeth. Photo: Supplied.