Researchers Blast Algae, Invasive Plants with UV Rays to Keep Lake Tahoe Blue.

RENO (AP) — Encouraged by three years of experimentation, scientists
at Lake Tahoe plan to expand the use of ultraviolet light to kill algae
and other invasive plants that eat away at the clarity of the mountain
water.

Researchers at the University of Nevada, Reno are monitoring
the project and collecting data to study the effects of the
ultraviolet-C light treatments. It’s the newest tool in a two-decade
effort to restore the once-pristine waters in the lake straddling the
California-Nevada line.

 

 The pilot project on the south shore showed that applying the light
treatment caused invasive plants to deteriorate or completely collapse
within seven to 14 days of treatment.

“This exciting, innovative approach is one of the main methods being
considered in combination with other technologies to control weeds in
the Tahoe Keys, which comprise the biggest aquatic weed infestation in
Lake Tahoe,” said Dennis Zabaglo, manager of the Aquatic Resources
Program at the Tahoe Regional Planning Agency.

The new tool is a light fixture called an array mounted under a
working barge, which trolls the marina dousing the plants on the bottom
with UV-C light, a short-wave electromagnetic radiation light that
damages the DNA and cellular structure of aquatic plants.

The technology developed by John J. Paoluccio, president of Inventive
Resources Inc., is being used at Tahoe to kill Eurasian watermilfoil
and curlyleaf pondweed. In addition to reducing clarity, invasive plants
can clog waterways and provide cover for other non-native species,
including bass and blue gill.