A necropsy on the killer whale that died after being stranded off northern Vancouver Island shows she was pregnant with another calf.

Marine scientist Jared Towers watched the necropsy on the animal and says the 15-year-old Bigg's killer whale was expecting another calf when she became trapped in shallow waters near the community of Zeballos.

Towers, who's with the research group Bay Cetology, says scientists, area First Nations and volunteers are now focusing their efforts on coaxing the killer whale's two-year-old calf out of the lagoon, but the timing of the tidal waters only offers a daily opportunity of about 30 minutes for the animal to swim out of the lagoon.

He says the young whale, which has been in the area since Saturday, has so far resisted their efforts to leave the lagoon, which included them using speakers sending out audio of whale calls.

Towers says the calf appears healthy and is making regular vocal calls, while it spends much of its time in the deepest part of the lagoon, estimated at about 30 metres.

The Fisheries Department's marine mammal rescue experts have said the goal is to convince the calf to leave the lagoon in the hope that it can reconnect with other members of its family.

The female orca was stranded on shore in Little Espinosa Inlet, about six kilometres southwest of Zeballos, at low tide while a calf swam nearby.

Video of the incident shows dozens of people trying to save the stranded orca.

Ehattseaht First Nation Chief Simon John told CBC All Points West host Jason D'Souza the calf is essentially in a lagoon he described as an "inlet that goes into another smaller inlet that goes into a bigger inlet and gets in the ocean ... so it's quite complex, what it has to navigate in order to get into its pod."

"It's pretty intense work.. just trying to think [of] a way out of it."

He said the calf had been given the name kwiisaḥiʔis, which translates roughly to "Brave Little Hunter."

He said he remains hopeful kwiisaḥiʔis can be coaxed back to the ocean and reunited with its pod.

"It's about giving it what it needs," he says.

While the circumstances around the stranding remain unclear, Marine Education and Research Society (MERS) — a conservation charity based in Port McNeill — speculates the orca may have ventured ashore during a high tide, possibly for hunting purposes.

In a social media post, the society said the area where the incident took place "is highly influenced by changes in tides."

"When the tide ebbs in this particular spot, it happens very quickly," the society wrote.