A ghastly green goo has invaded the upper duck pond in Ashland's Lithia Park, causing visitors and park officials alike to wonder what went wrong.

A ghastly green goo has invaded the upper duck pond in Ashland's Lithia Park, causing visitors and park officials alike to wonder what went wrong.

"It looks like split pea soup," said Medford resident Molly Kerr.

Her husband, Larry, said he was taken aback when he first gazed on the pond after a month's absence and wondered, "What's that?"

That green stuff is duckweed, according to Donn Todt, head gardener at Ashland Parks and Recreation Department.

About a month ago, a patch the size of a children's inflatable swimming pool was first noticed. Within three weeks the duckweed had covered the entire pond.

Todt said in his 30 years with parks and recreation he has never seen anything like it. But he has come up with a few explanations about what went wrong.

In 2005, the city decided to prohibit feeding ducks because of ongoing water quality problems.

The lack of feed has meant fewer ducks visiting the pond, said Todt. The ducks normally eat not only the feed, but also the duckweed.

"Normally there would be 150 ducks or more here, but now we've got maybe 12 or so," said Todt.

But the lower pond near the entrance to Lithia Park doesn't have the same problem, which Todt thinks is because the upper pond is in a more sheltered area. That protects it from the wind but still allows enough sun in to make the duckweed bloom. Winds normally will drive the plant up onto the banks, where it dries out.

He suspects the ducks as the culprits in transporting the aggressive plant into the pond.

Pushing aside the light green layer of duckweed that he says poses no health risks, Todt revealed water that is surprisingly clear and fairly cool to the touch, though he did pull out a bunch of algae, known as nitella.

The duck weed doesn't feel slimy, but has a texture more like little sprouts and is a bit clingy and difficult to shake off your fingers.

To control the infestation for the long term, Todt said, city officials will install pumps and pipes to circulate irrigation ditch water through the pond, a job that should be completed sometime in September. The fresh water, which will also help stave off algae problems, will then be used to irrigate the park. Todt said the project will make Ashland less reliant on city water for irrigation.

During the winter months, the duckweed will die back with the cooler temperatures, he said.

While city officials think a solution may be at hand, mystified visitors have come to their own conclusions.

"We went 'yuck' and thought it was algae," said Kathy Robbins, a 62-year-old Ashland resident.

Her husband, Neil, said, "It was intriguing and confusing to some degree. I didn't know what I was looking at."

After getting a brief explanation of the duckweed, she said, "We could dry it out, put it in little pills and sell it in the health food store."

Sahib-Anar Khalsa visits Ashland every summer and makes a point of stopping by the duck pond. She struck up a conversation with a family about what they saw.

"It looks like a green ice skating rink," said the 62-year-old Richmond, Calif., resident.

Khalsa's new friend, Maggie Klaus, said, "I grew up here, and we're just visiting, and it's so sad."

The 29-year-old Los Angeles resident's daughter, 1-year-old Jaylin Hodgon, didn't seem to mind the green pond or the ducks, who apparently thought the cereal she was eating looked more appetizing than the duckweed.

Jaylin's mother said seeing the ducks brought back fond memories of going to Lithia Park for the first time on a vacation when she was only 2.

"We were feeding the ducks and I fell in," she said. "I was just covered in muck."

Reach reporter Damian Mann at 776-4476 or dmann@mailtribune.com.