Idaho reports limited quagga detection, completes expanded Snake River treatment and statewide testing increase

The Idaho State Department of Agriculture (ISDA) briefed the House Agriculture Affairs Committee on Feb. 18 about expanded quagga and zebra mussel surveillance and a large-scale treatment on the Snake River following detections in 2023 and 2024.

ISDA Director Chanel Tewalt and bureau chief Nick Zerflue described a rapid, multi‑partner response that increased inspections, doubled statewide water sampling and added laboratory redundancies and external subject-matter review in 2024. "We have increased by every single measure what we do in this program," Tewalt said, noting more stations, more hours, more communication and more partners.

ISDA fieldwork and lab confirmation: Tewalt and Zerflue said the department uses a multi-layered confirmation process: initial plankton-net sampling for veligers, visual assessments, double-blind review with outside taxonomic experts, molecular confirmation and cautious use of environmental DNA (eDNA). Tewalt cautioned that eDNA can be imprecise and stressed the department’s effort to avoid false alarms by combining methods. Zerflue emphasized redundancies in lab review and cross‑state consultations to speed and validate sample identification.

Delimitation and treatment…