Invasive water weed starting to spread in Southcentral, alarming biologists

A water weed native to eastern North America has taken hold in Alaska so quickly that government biologists are calling for an emergency public mobilization to eradicate it. Elodea, commonly grown in aquariums and included in school science kits, was unheard of in Alaska as recently as five years ago. Since then, it has been found in Fairbanks as well as Anchorage and Cordova and is now spreading in Kenai Peninsula lakes, threatening fish as well as transportation, according to The Redoubt Reporter.

The plant thrives in cool water conditions and even continues to grow under the ice in winter. In the Lower 48 and in Europe, elodea outbreaks have gotten so thick that the growth has to be mechanically mowed with specialized equipment, or removed by backhoe as part of the eradication process.

“It grows so abundantly that it literally shuts down the ability to run a boat motor through it. It’ll foul floatplane rudders and boat props. It’ll foul launch sites and shore habitats, and it degrades salmon spawning habitat,” said Libby Bella, a [Kenai National Wildlife] refuge ecologist.

“So it’s not just ecological damage, but economic damage that can happen from it radically changing habitat,” Bella added. 

Last week, biologists from several state, federal and conservation agencies cut through ice at Daniels Lake near Nikiski and discovered elodea thriving beneath the ice. “When we augered the hole and water splashed out, the elodea splashed out with it, vibrant and green. There was essentially no dieback in winter,” John Morton of the KNWR told The Redoubt Reporter.

Methods of battling elodea include chemicals and vacuuming, but they're expensive and require buy-in from anyone owning lakefront property. 

Read more: Danger in the deep — Invasive elodea plant threatens to strangle peninsula waterbodies