PT  - JOURNAL ARTICLE
AU  - Taal Levi
AU  - Jennifer M. Allen
AU  - Donovan Bell
AU  - John Joyce
AU  - Joshua R. Russell
AU  - David A. Tallmon
AU  - Scott C. Vulstek
AU  - Chunyan Yang
AU  - Douglas W. Yu
TI  - Environmental DNA for the enumeration and management of Pacific salmon
AID  - 10.1101/394445
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 394445
4099  - http://biorxiv.org/content/early/2018/12/06/394445.short
4100  - http://biorxiv.org/content/early/2018/12/06/394445.full
AB  - Pacific salmon are a keystone resource in Alaska, generating annual revenues of well over ∼US$500 million/yr. Due to their anadromous life history, adult spawners distribute amongst thousands of streams, posing a huge management challenge. Currently, spawners are enumerated at just a few streams because of reliance on human counters and, rarely, sonar. The ability to detect organisms by shed tissue (environmental DNA, eDNA) promises a more efficient counting method. However, although eDNA correlates generally with local fish abundances, we do not know if eDNA can accurately enumerate salmon. Here we show that daily, and near-daily, flow-corrected eDNA rate closely tracks daily numbers of returning sockeye and coho spawners and outmigrating sockeye smolts. eDNA thus promises accurate and efficient enumeration, but to deliver the most robust numbers will need higher-resolution stream-flow data, at-least-daily sampling, and a focus on species with simple life histories, since shedding rate varies amongst jacks, juveniles, and adults.