Environmental DNA pilot monitoring program for invasive species and biodiversity assessments on Santa Cruz Island: Interim report, September 2025

Science Report NPS/SR—2026/381
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Abstract

The U.S. Geological Survey (USGS) and Southern California Coastal Water Research Project supported Channel Islands National Park, The Nature Conservancy’s (TNC) Santa Cruz Island Preserve, and University of California San Diego (UCSD) researchers in using environmental DNA sampling to monitor for invasive Argentine ant (Linepithema humile) and to describe spatial biodiversity patterns in a freshwater stream on Santa Cruz Island that is colloquially known as Cañada del Puerto Creek (hydrologic unit code 12 number 180600140201). An eDNA autosampler was deployed May 27–June 02, 2025, which filtered and preserved four 2-L water samples every 12 hours (n = 48 samples). These samples were extracted by USGS and shipped to UCSD for targeted eDNA analyses of Argentine ant. Environmental DNA sampling kits were used to filter and preserve water samples at four sites along the creek spanning ~ 5 km of stream distance. Six 1-L samples were collected at each site May 27–28 and samples were analyzed for eDNA metabarcoding using a comprehensive panel, which encompasses species across the tree of life. In these samples, eDNA from 2,134 unique taxa spanning 30 taxonomic groups (e.g., amoebas, insects, plants) were found. These sampling efforts demonstrated how eDNA autonomous and manual sampling approaches can be applied by National Park Service, TNC, and partners at scale to provide otherwise difficult and expensive to acquire information about biological threats and biodiversity.

Suggested Citation

Sepulveda, A., Theroux, S., 2026, Environmental DNA pilot monitoring program for invasive species and biodiversity assessments on Santa Cruz Island: Interim report, September 2025: Science Report NPS/SR—2026/381, vii, 8 p., https://doi.org/10.36967/2317065.

Study Area

Publication type Report
Publication Subtype Federal Government Series
Title Environmental DNA pilot monitoring program for invasive species and biodiversity assessments on Santa Cruz Island: Interim report, September 2025
Series title Science Report
Series number NPS/SR—2026/381
DOI 10.36967/2317065
Publication Date February 01, 2026
Year Published 2026
Language English
Publisher National Park Service
Contributing office(s) Northern Rocky Mountain Science Center
Description vii, 8 p.
Country United States
State California
Other Geospatial Santa Cruz Island
Additional publication details