VANCOUVER – More than 150 koi have adjusted well to their new temporary home, according to a koi specialist housing them.

On Friday and Saturday, Vancouver Park Board staff rescued the fish after another otter mysteriously showed up at Chinatown's Dr. Sun Yat-Sen Garden.

The hungry critter is blamed for having expensive taste and eating six mature koi last week.

Last November, a similar situation played out at the garden where 11 koi were found dead, including one believed to be 50 years old.

At the time, an otter was seen by staff and visitors – yet, it managed to evade capture.

Unlike last year, the park board did not hesitate to remove the fish, bringing them to a facility in Richmond.

"Generally, moving fish when it is this cold is not advised, but because this is a special situation and I had an environment which was perfectly temperature controlled to acclimatize them from the outside temperature," said Sid Cheung, the specialist taking care of the koi.

Cheung said one mature koi has battle wounds.

"One fish is slightly injured from either being captured or being attacked," he said. "The tail is a bit chewed up."

But overall, he said the fish are "happy and eating."

"They're swimming freely -- no clamped fins. They're swimming like they are in the pond or in the wild," he said.

Otter gone for now?

Over the weekend, park board staff set six baited live traps throughout the park, hoping to find the river otter in one of them on Monday morning.

Instead, staff who checked the traps found them empty.

Officials are unclear how the critter managed to get in.

David Rosen, a UBC assistant professor who works in the marine mammal research unit, said otters are known to be escape artists.

"We know they can climb trees, so in urban environment, they can probably climb walls or drain pipes. It's really hard to make a facility otter-proof," said Rosen.

During "Otter Watch 2018," the suspect eventually left the park on its own, presumably because there were no more koi left to eat in the pond.

Rosen suspects it may be the same otter that's returned.

"The reason I think it might be the same river otter is because it's an animal that thinks it's found a good food source, so it's come back to take advantage of it this year," he said. "This could just be a local otter that's come up with this hunting behaviour that we have to adjust to."

After being closed over the weekend, the public portion of Dr. Sun Yat-Sen re-opened Monday morning.

The park board says it does not plan to put the baited traps back out unless there is another sighting of the otter.

In the meantime, staff are exploring ways to make the pond more secure before returning the koi to the water.