Column: Our fight against aquatic invasive species

By motor or by paddle, the experience of boating on Lake Tahoe is like none other. Hovering over its crystal clear shallows and unfathomable depths inspires awe, and the surrounding mountains and forests combine for a breathtaking experience. Given this, it is understandable that boating is both a major part of Tahoe’s culture and its regional economy. Visitation by boaters from outside the region is always high—approximately half the boats entering the lake also launch in other waters—and COVID-19 has only served to ramp the intensity up as people look to escape more populated areas and drive from further afield to avoid the risk of air travel.

While Lake Tahoe thrives on visitation, travelling boats and trailers are the most common vector for the spread of something that can devastate Lake Tahoe’s fragile ecosystem—aquatic invasive species. And more boats arrived contaminated with invasive species this year within the first month than all of last season combined. Fortunately, inspectors caught them.

Invasive species are a critical threat to Tahoe’s environment, economy, and boating heritage. There are many invasive species that threaten, and some, like watermilfoil and pondweed, are already here and being fought through a comprehensive control program. However, some of the most dangerous are not here, quagga and zebra mussels among them. Coming from the Great Lakes region, these mussels have spread across most western states and all the way to the Gulf of Mexico, damaging beaches, aquatic life, water systems and public and private infrastructure as they spread. Should they establish here, the impact would be catastrophic and there is no known method of removal. Controlling the damage could cost an estimated $20 million a year, posing a big impact to Lake Tahoe’s $5 billion regional economy should our waters and beaches become littered with jagged shells as has happened in other areas.

Since 2008, the Tahoe Regional Planning Agency (TRPA) has made invasive species a top priority. To protect the very things that entice so many to boat and paddle on these deep blue waters, TRPA, the Tahoe Resource Conservation District, and our partners created what is today the nation’s leading watercraft inspection and decontamination program. Unlike other inspection programs, at Lake Tahoe every vessel coming from outside the basin must receive an inspection before launch. The strength of the inspection program lies in the collaboration upon which it is built. With the support of boaters, private marinas, and public launch managers, there have been no new invasive species detections in the region in the program’s 12-year history. Over that time, more than 90,000 boats have been inspected and, on average, half of them have been decontaminated from stem to stern to further reduce the risk of another invasive species introduction.

Not all boats on Tahoe need to be inspected. With the partnership of every marina and launch site in the basin, vessels that come out of the lake are sealed with a unique, numbered clip. Each vessel that returns to a launch site with an intact seal is certified free of invasive species and is clear to launch without waiting for an inspection. In its entirety, the program represents the coming together of science and common-sense policies.

Maintaining the highest standards of protection this year has not been easy. At first, shelter-in-place orders and travel restrictions kept inspection stations closed. Working closely with the Tahoe Resource Conservation District who manages the inspection stations, an appointment system was created to adhere to COVID guidelines. Through the appointment system, we are protecting inspectors and boaters from the spread of the virus. We are reducing crowding at inspection stations, allowing time to clean and reset between inspections, and are able to communicate clearly and safely with boaters through the inspection process. Tahoe like most recreation areas in the Sierra Nevada is experiencing record numbers of recreators and demand for inspections is sometimes outpacing available staffing and capacity. The inspection appointment system fills as quickly as new inspectors are hired and trained and efficiencies are added. Despite some frustration, overall boaters continue to support the inspections as a means to protect what matters most to them—a quintessential boating experience.

Through the ins and outs of our COVID response, invasive species haven’t slowed. Since inspection stations re-opened in May, fourteen vessels carrying invasive species have been intercepted, one of which was encrusted with mussels that can survive days out of water. By contrast, eight infested vessels were intercepted all of last year. We cannot let our guard down in this fight. Please join me in spreading the word to the boating public about the importance of keeping Lake Tahoe mussel-free and protected from harmful invasive species.

- Joanne S. Marchetta is the Executive Director of the Tahoe Regional Planning Agency