MUSSELING IT OUT

Both Mono and Inyo Counties recently approved ordinances that legally require boats to undergo inspections in order to enter waterways in an effort to prevent the spread of the invasive golden mussel.

First detected in California last fall, golden mussels have spread rapidly on the west side of the state, but so far have not reached the Eastern Sierra. To keep them at bay, local stakeholders  have been racing to strategize a way to keep the species out of regional waters before the fishing opener this spring.

The effort is part of a larger, coordinated regional response known as the Eastern Sierra Golden Mussels Collaborative, which grew out of the Mono County Golden Mussel Ad Hoc Committee.

“This program is not necessarily the responsibility of Mono County or Inyo County,” said Marcella Rose, Mono County Outdoor Recreation Superintendent. “But within this collaborative, it’s been well established that there’s a moral imperative to act now.”

The ordinances will become effective mid-to-late-April, depending on when they are passed.

Mono County Supervisors approved its ordinance this week, and Inyo County approved it Feb. 17. The Mammoth Lakes Town Council and City of Bishop Council are expected to review similar ordinances in the coming weeks.

Trailered boats are considered the primary risk for mussel spread because they can retain water, unlike kayaks or paddleboards. The new ordinances require that all trailerable boats entering Mono or Inyo counties undergo inspection and, if needed, decontamination before entering any water body. Boats that pass inspection receive a sticker as proof of compliance.

Residential boat owners will need to get an annual inspection, while visitors will have to undergo inspections monthly or whenever traveling from waters outside Mono County.

The regulations designate the first two violations as infractions, while a third offense could be charged as a misdemeanor, at the discretion of the district attorney. Repeated noncompliance can result in boat impoundment.

The program builds on a pilot inspection and decontamination (“WOD”) station launched over Labor Day weekend 2025. The pilot found that voluntary inspections are insufficient for compliance, and prompted the need for mandatory ordinances.

There are existing inspection stations at Lake Diaz, Klondike Lake, Crowley Lake, and Topaz Lake, but the collaborative plans to add new stations in Lee Vining, Bishop, and Bridgeport to improve coverage.

The first-year program budget is approximately $75,000, including staffing and outreach costs.

Stations and decontamination equipment are being borrowed for the initial year, with inspections offered free of charge in the first year to encourage compliance.