Distribution and Abundance of Alvord Chub in Oregon and Nevada

Abstract Alvord Chub are small minnows endemic to the Alvord Basin, a endorheic desert basin in southeastern Oregon and northwestern Nevada. Comprehensive distribution surveys were last conducted 30 y ago. Recent, limited surveys raised concern that the range and abundance of Alvord Chub may have contracted. We conducted a comprehensive survey at historically occupied locations in 2013 and obtained mark-recapture population estimates. Despite 2 y of below average precipitation, Alvord Chub were present at the majority of historically occupied drainages, were abundant at many locations, but were restricted in distribution in several drainages. Additionally, we documented current threats, which included water withdrawals, nonnative fishes, grazing, habitat fragmentation, and desiccation. Based on our observations, we suggest a number of management recommendations.