Zoo's penguins finally on view

Zoo's penguins finally on view
Cloudy water kept visitors from seeing main attraction

By FIONA COHEN
SPECIAL TO SEATTLEPI.COM

Ten days after the public opening of Woodland Park Zoo's new Humboldt penguin habitat, one of the $6.5 million exhibit's problems was solved.

People could see the penguins.

For the first part of May, that was not the case. An algae bloom clouded the water, making it hard to see far in the tank. And the penguins didn't help. The 20 birds clustered in the deep end of the exhibit, well under the murky water.

Probably the worst day was May 9, when a record crowd of 14,700 people came through the zoo gates enjoying a Mother's Day promotion and sunny weather.

But by last Wednesday, viewers could finally see the back wall of the tank from all the windows.

Monica Lake, the project manager for the exhibit, was thrilled.

"I dropped to my knees this morning and prayed to the god of water clarity," she said.

The reason the water clouded up had to do with the filtration system the penguin exhibit used. Rather than draining and refilling the tank, the zoo reuses the exhibit's water -- a practice that saves an estimated three million gallons annually.

When it leaves the penguin tank, the water passes through a wetland area just outside the exhibit entrances, then goes through some mechanical and biological filters before returning to the water. All 41,000 gallons circulate every 36 minutes.

Bacteria on the filters remove ammonia from the water -- but those bacteria take time to grow. Meanwhile ammonia was building up in the tank, and the water turned cloudy.

But the problem is temporary, said Ted Maranda, the civil engineer who designed the system -- and many other aquariums around North America.

"Once the bacteria gets settled in, they take ammonia and the water all of a sudden magically clears up," he said.

Maranda said zoo staff made the situation worse by washing out the particulate matter filters too often. The filters work better when they're dirty, he explained.

"They just had to leave it alone," he said.

Maranda expects that the visibility will continue to be good -- though he can't say for sure. It's possible that as the temperature changes over the year, there may be other algae blooms.

"Until you're operating this system over a year, you don't know what to expect from seasonal changes," he says.

The same week the water cleared, the penguins started to spend more time at the shallow end of the exhibit. They started playing in the exhibit's wave feature -- a spot they had avoided since they arrived to the pool on April 7.

When they had their weekly live trout feeding on Friday, several penguins darted after the fish in the shallow end -- led by Raul, a male with a blue-and-white marker on his right wing.

Raul is a particularly intelligent and bold penguin, said Celine Pardo, one of the zoo's two penguin keepers.

"He's the only one that's figured it out," she said.

It was Pardo's day off, but she came to watch the feeding.

"I like to see them having fun," she said.

Each penguin has a distinct personality. Dora, who has a yellow tag on her left wing, is a fussy eater. During frozen fish feedings, she usually hangs back while the keepers give out herring and capelin, only eating when they're putting out silver-sides. Meanwhile, Burkles, a penguin with a white tag on his right wing, likes to help himself. He'll walk behind his keepers and look in their pockets, or try the food bucket.

"He's a bucket diver," Pardo said.

Burkles was less keen on catching live fish. John Samaras, the other penguin keeper, had to nudge him into the water.

Humboldt penguins come from the coasts of Chile and Peru. They are an endangered species, with 12,000 or fewer remaining.

There are 10 males and 10 females in the Woodland Park Zoo exhibit, all from other North American zoos. Some have already formed pair bonds, but zoo staff don't expect them to breed soon. The nest holes in the exhibit's artificial cliffs are blocked up, to be opened next spring.

But eventually, the zoo should be getting some new arrivals, in the form of chicks. The exhibit can house up to 60 penguins.

Lake said the zoo opened the exhibit, water problems and all, because people wanted to see the animals.

"We could have opened the exhibit later, but people were just climbing the walls to get in there," she said.

Some visitors on Mother's Day weekend were disappointed they couldn't see the birds.

"What we got mainly were people concerned that they had to lift the kids to see the penguins," zoo spokeswoman Rebecca Whitham said.

As for the penguins, they like seeing the people.

"The birds enjoy the public. They like to look at them through the glass," Pardo said. "They like little kids with shiny shoes and sunglasses and fast-moving hands."

Fiona Cohen is a Seattle-based freelance writer. She blogs at naturegeeknw.blogspot.com.

Source:
http://www.seattlepi.com/local/406281_penguins18.html