YOUR AD HERE »

Forum outlines invasive species problems, solutions

Jack Barnwell
jbarnwell@tahoedailytribune.com
Savannah Rudroff, natural resources coordinator for the League to Save Lake Tahoe, speaks about the league's Eyes on the Lake program at the 5th Annual Aquatic Invasive Species Forum on Thursday.
Jack Barnwell / Tahoe Daily Tribune |

MEYERS — An informational campaign launched for the fifth time Thursday to combat the aquatic invasive species infesting the Tahoe-Truckee watershed.

Experts gathered at the Lake Tahoe Golf Course to touch on everything from Asian clam found throughout the lake to the Eurasian milfoil choking the Tahoe Keys lagoons.

The prognosis: Some good news, some not so pleasant.



Aquatic invasive species (AIS) are plants and animals that aren’t native to the Tahoe-Truckee environment. Those include two types of non-native plants and five types of animals.

Nicole Cartwright, Tahoe Resource Conservation District’s AIS program coordinator, said non-native species “cause devastating effects to our economy and recreation.”



Non-native species also alter the nutrient cycles and food supplies of the native species and facilitate algal growth.

Cartwright said the various agencies in Tahoe have focused on preventing more non-native species coming in. This has resulted in what she called one of the most rigorous inspection programs in the United States.

Some accomplishments in the past have included a years-long process that removed invasive weeds from Emerald Bay by 2014.

Marion Whitman, a researcher from University of Nevada, Reno, said a task force has been established nationwide to help combat and control invasive species. Lake Tahoe has its own AIS coordination committee as well.

Whitman said Tahoe has a regional interstate management plan in development. Implementation efforts have included coordination and historical record evaluation to locate AIS populations.

An outside panel of experts and the Tahoe AIS coordination committee has taken a stab at the plan and its final draft should be complete June 2, 2015.

Dennis Zabaglo, aquatic resources program manager for Tahoe Regional Planning Agency (TRPA), highlighted the success of a pilot program to remove Asian clams from a portion of Emerald Bay.

The Asian clam population exploded in 2009, corresponding with an increase in algal growth. Zabaglo said TRPA selected Emerald Bay as a pilot project to exterminate the population in a five-acre program.

The two-year project involved laying 10-foot-by-100-foot milled aspen fiber mats on the lake’s floor in 2012. The mats suffocated the clams and resulted in a 80 percent mortality rate by December 2014.

“That’s a pretty significant rate,” Zabaglo said. While effective, he said the method was also expensive and complex.

“You’ve got to have multiple tools, and so moving forward we’re going to take steps to research other projects,” Zabaglo. One of those includes Aqua Treasures, a company that uses a Zamboni-type machine to scrape clams and mussels from the lake bottom without damaging the environment.

Rick Lind, president of Sierra Ecosystems Associates, highlighted efforts conducted by the Tahoe Keys Property Owners Association (TKPOA) to curtail milfoil growth in the area’s lagoons.

The TKPOA in 2013 retained an expert, Dr. Lars Anderson, to develop and execute a integrated weed management plan.

Approximately 80 to 90 percent of the Tahoe Keys three lagoons are infested with aquatic weeds. The amount harvested has jumped significantly in the last seven years, from 4,400 cubic yards in 2007 to 18,600 cubic yards in 2014.

Lind said the Keys is likely the major source for weeds that spread to other parts of the lake, and provides a breeding ground for warm water fish like giant goldfish and largemouth bass.

He said the TKPOA and the Keys’ five major private property owners would have to work together in order to ensure the plan is effective.

The current weed removal method is the Keys’ five harvesters, an intensive method that requires the weeds to be dried and transported to Carson City for composting.

TKPOA’s plan will include boat monitoring, improving the native species’ habitat, and restoring recreational uses. TKPOA is also considering a number of approved herbicides. Lind said the goal is to have a public plan by Fall 2014 and a completed environmental review by February 2017.


Support Local Journalism

Support Local Journalism

Readers around the Lake Tahoe Basin and beyond make the Tahoe Tribune's work possible. Your financial contribution supports our efforts to deliver quality, locally relevant journalism.

Now more than ever, your support is critical to help us keep our community informed about the evolving coronavirus pandemic and the impact it is having locally. Every contribution, however large or small, will make a difference.

Your donation will help us continue to cover COVID-19 and our other vital local news.