A new study on humpback whales has recorded them attempting to save other marine life from being eaten on hundreds of occasions.

A team of researchers, led by Robert Pitman, a marine ecologist with NOOA Fisheries' Southwest Fisheries Science Centre, found evidence to suggest that humpbacks may engage in altruistic behavior during encounters with killer whales attacking other marine species.

Pitman began his research when he observed a humpback whale come to the rescue of a seal after a pod of killer whales had knocked it off an ice block in 2009. After the orcas managed to knock the seal off the ice, Pitman was shocked to see a humpback whale rise up from under the seal, blocking the orcas from harming it.

"Anecdotes have been passed down for centuries about dolphins at sea coming to the aid of distressed members of their species, as well as other species, including humans," Pitman explained.

In a paper published on Marine Mammal Science's website, the team describes their study of humpback whale encounters with killer whales and explain why they believe it is possible the whales are intentionally helping other creatures.

They conducted searches in both published and unpublished papers, detailing humpback observations and discovered 115 incidents of humpback whales rescuing other creatures from orca attacks.

They also noted that just 11 of the incidents involved rescuing humpback whale calves - the rest involved other marine creatures, such as gray whales and sea lions.

"More often, though, humpbacks approached MEKWs (mammal-eating killer whales) that were attacking prey species that were clearly not humpbacks (e.g. a grey whale calf with its mother, a seal hauled out on an ice floe, a sunfish), and although the humpbacks faced little risk of serious injury, they also gained no obvious benefits for their time and energy spent."