Those driving along the Delta Highway north of the Valley River Center Mall may notice a unique quirk of the Delta Ponds this time of year: they are red.
The red stuff adorning the 150-acre waterway site isn’t algae or autumn leaves or dye, but an aquatic fern. Waterway enjoyers shouldn’t be alarmed, though, as the fern is actually beneficial to the local ecosystem, according to local experts.
Lauri Holts, the Parks and Open Spaces ecologist for the city of Eugene, said this red-brown aquatic fern, called Azolla, is often an attention-grabber for Eugenians who notice the ponds’ change.
“We get calls every year … people think paint’s been spilled,” said Holts, who oversees all city-owned waterways including ponds, parts of the Willamette River and Amazon Creek. “We get a lot of people that want to know if we’re going to control it and and I say, no, it’s natural. We wouldn’t want to use a bunch of chemicals. It’s just going to come back, so there’s no reason to do that. And it has ecological benefits.”