Hope lost for sick orca?

UPDATE: 7:05 p.m.

A scientist says there is "no chance" a sick killer whale at the centre of an international effort to provide the orca with medical treatment will be found alive.

Ken Balcomb of the Center for Whale Research in Washington state said the southern resident killer whale known as J50 hasn't been seen for several days and he believes she died between last Friday and Monday.

"I know that she is gone for a week and deceased," he said Thursday. "There is no chance that she will still be alive, so we're writing her off."

He said the last sighting was by a biologist on Friday evening and her pod, including her mother, has been seen off the coast of British Columbia and Washington state since then without the three-year-old whale.

"The remains have sunk, no doubt, because she was so skinny that she didn't have anything that would float her," said Balcomb, who tracks killer whales. "No significant blubber layer, her lungs wouldn't hold much air to float the carcass so she probably sank somewhere … in deep enough water that she's not going to buoy up from decomposition."

However, the U.S. National Oceanic and Atmospheric Administration and Fisheries and Oceans Canada haven't given up hope.

NOAA spokesman Michael Milstein said the search for J50 continues. The West Coast Marine Mammal Stranding Network and airlines flying in and out of the San Juan Islands are on the lookout, he said.

He said J50 was last seen Friday afternoon off the west side of the islands and hasn't been seen since.

Fisheries and Oceans said in a new release it was co-ordinating with NOAA to continue the search by water and air. Teams are ready to respond if J50 is located and requires medical attention, it said.

---

ORIGINAL: 1:10 p.m.

A sick killer whale that has been the subject of an international effort to provide her with medical treatment is missing from her family group and hasn't been seen for days.

J50 has fallen behind before but a spokesman for the fisheries department of the U.S. National Oceanic and Atmospheric Administration says she hasn't been sighted for several days.

Michael Milstein says in an email that sea conditions were favourable and there have been sightings of her pod, including her mother, but there has been no sign of the three-year-old orca.

He says teams have been on the water searching an increasingly broad area in Canadian and American territory.

The West Coast Marine mammal Stranding Network has been notified and airline crews flying out of the San Juan Islands were keeping watch.

On Wednesday, experts on both sides of the border said they may have to take extraordinary measures to save the emaciated whale, which is one of 75 remaining members of the endangered southern resident killer whale population.

Officials said they were setting out steps to capture and treat J50 if the whale is found stranded or separated from her family, and that she would then be released back to the wild.