Appendix - Environmental DNA Results
This appendix carries the site-level detail behind the headline counts in the Results chapter. Field blanks are reported separately because they test the sampling protocol rather than a location. Office blanks are excluded entirely — they are distilled-water controls filtered at the end of a session at accommodation, so although they carry real GPS coordinates, those coordinates record where the filtering happened rather than a stream site. The interactive map is linked at the end.
Per-site detection results
Format: CODE(max_droplets), with * flagging samples that UNBC reran. Detected = ≥4 positive droplets, the call threshold applied by the laboratory. Everything below that threshold is reported as not detected, including 2-3 droplet results that were retested without reaching the cutoff.
A non-detection is only as strong as the evidence that the reaction worked. Internal amplification controls — the lambda-phage and exogenous-plant spike-ins that show a well amplified — were reported for only a minority of samples in this batch. Where they are absent, a zero cannot be distinguished from a failed or inhibited reaction, and the “Not detected” column below should be read as untested rather than negative. Detections are unaffected, since a well returning positive droplets demonstrably amplified.
edna_per_site |>
fpr::fpr_kable(
caption_text = "Site-level eDNA detection results across real environmental samples in the Fraser project area. UNBC ID is the lab sample identifier; Pos. control = yes indicates the sample was collected at a site where the target species was also confirmed by electrofishing.",
scroll = gitbook_on
)| Site ID | Stream | UNBC ID | Pos. control | Detected | Not detected |
|---|---|---|---|---|---|
| 126158_ds_ed1 | Tributary To Stony Lake | F61121 | RAIN(77) | BULT(0), CHIN(0), COHO(0) | |
| 126158_us_ed1 | Tributary To Stony Lake | F61122 | yes | RAIN(21) | BULT(0), CHIN(0), COHO(0) |
| 126349_ds_ed1 | Tributary To Cameron Lake | F21236 | RAIN(39) | BULT(0) | |
| 196076_ds_ed2a | Tributary To Fraser River | F41016 | RAIN(23) | BULT(0), BURB(1), CHIN(0) | |
| 196076_ds_ed2b | Tributary To Fraser River | F41017 | RAIN(5) | BULT(0), BURB(0), CHIN(0) | |
| 196076_us_ed1 | Tributary To Fraser River | F61125 | RAIN(44) | BULT(0), CHIN(0), COHO(0) | |
| 196085_ds_ed1 | Tabor Creek | F40915 | BURB(8), CHIN(181) | BULT(1), SOCK(0) | |
| 196085_us_ed1a | Tabor Creek | F41019 | CHIN(8), RAIN(6) | BULT(0), BURB(0) | |
| 196085_us_ed1b | Tabor Creek | F41020 | CHIN(144), RAIN(128) | BULT(0), BURB(0) | |
| 196200_us_ed1 | Bittner Creek | F60808 | — | BULT(0), CHIN(0), COHO(0), SOCK(0) | |
| 196332_ds_ed1 | S. Yuzkli Creek | F21237 | — | BULT(0), RAIN2(0) | |
| 196332_us_ed1 | S. Yuzkli Creek | F21238 | — | BULT(2), RAIN(0), RAIN2(0) | |
| 199171_ds_ed1 | Tributary To Fraser Lake | F60503 | RAIN(4) | BULT(0), CHIN(0), SOCK(0) | |
| 199171_us_ed1 | Tributary To Fraser Lake | F60504 | — | BULT(0), CHIN(1), RAIN(3), SOCK(0) | |
| 199173_ds_ed1 | Tributary To Nechako River | F61126 | CHIN(16), RAIN(255) | BULT(0), COHO(1) | |
| 199173_us_ed1 | Tributary To Nechako River | F61127 | yes | RAIN(512) | BULT(0), CHIN(0), COHO(0) |
| 199174_us_ed1 | Tributary To Nechako River | F61128 | RAIN(38) | BULT(0), CHIN(0), COHO(0) | |
| 199190_ds_ed1 | Creek Creek | F60505 | RAIN(17) | BULT(0), CHIN(0)*, COHO(0), SOCK(0) | |
| 199190_us_ed1 | Creek Creek | F61129 | — | BULT(0), CHIN(0), COHO(0), RAIN(0) | |
| 199237_ds_ed1 | Snowshoe Creek | F60809 | — | BULT(0), CHIN(0), COHO(0), SOCK(0) | |
| 199237_us_ed1 | Snowshoe Creek | F60810 | — | BULT(0), CHIN(0), COHO(0), SOCK(0) | |
| 199267_ds_ed1 | Driscoll Creek | F60811 | CHIN(4) | BULT(1), COHO(0), SOCK(0) | |
| 199267_us_ed1b | Driscoll Creek | F20401 | — | BULT(1), CHIN(0) | |
| 199273_ds_ed1 | Hankins Creek | F60812 | BULT(10) | CHIN(0), COHO(0), SOCK(0) | |
| 199278_ds_ed1 | Teepee Creek | F61131 | BULT(127), RAIN(47) | CHIN(0), COHO(0) | |
| 199278_us_ed1 | Teepee Creek | F61132 | BULT(138), RAIN(20) | CHIN(0), COHO(0) | |
| 203578_ds_ed1 | Tributary To Willow River | F61135 | RAIN(67) | BULT(0), CHIN(0), COHO(0) | |
| 203581_us_ed1a | Tributary To Fraser River | F61123 | RAIN(54) | BULT(2), CHIN(2), COHO(0) | |
| 203581_us_ed1b | Tributary To Fraser River | F61124 | RAIN(51) | BULT(0), CHIN(3)*, COHO(0) | |
| 203582_us_ed1a | Tabor Creek | F60506 | CHIN(56)*, RAIN(1281) | BULT(0), COHO(0), SOCK(1) | |
| 203582_us_ed1b | Tabor Creek | F60507 | CHIN(37)*, RAIN(1871) | BULT(0), COHO(0), SOCK(0) | |
| 23919_ds_ed1a | Swift Creek | F60813 | yes | BULT(62), CHIN(138), SOCK(332) | COHO(0) |
| 24715757_ds_ed1 | Snowshoe Creek | F20402 | BULT(4), CHIN(49) | — |
Field blanks
Field blanks filter distilled water at the field site to test for protocol contamination during collection and processing. Detections in blanks indicate potential cross-contamination, not species presence at the location — these rows are presented for QA transparency only, not as eDNA detections.
edna_field_blanks |>
fpr::fpr_kable(
caption_text = "Field blanks collected during the 2025 eDNA program in the Fraser project area. Detections in blanks reflect protocol-side contamination, not site eDNA.",
scroll = FALSE
)| Site ID | Stream | UNBC ID | Detected | Not detected |
|---|---|---|---|---|
| 199267_us_ed1a | Driscoll Creek | F61130 | — | BULT(0), CHIN(0), COHO(0), RAIN(0) |
| 23919_ds_ed1b | Swift Creek | F60814 | — | BULT(0), CHIN(0), COHO(0), SOCK(0) |
Retests
UNBC reran a subset of samples to confirm borderline results. The table below lists every site × species combination that was rerun, including reruns of both real environmental samples and field blanks.
if (nrow(edna_retests) > 0) {
edna_retests |>
fpr::fpr_kable(
caption_text = "UNBC retests for the 2025 Fraser eDNA samples. Runs is the total number of times the sample x species combination was assayed; Max droplets is the highest positive-droplet count observed across all runs.",
scroll = gitbook_on
)
} else {
cat("No retests in the Fraser 2025 batch.\n")
}| Site ID | Stream | Species | Code | Sample type | Runs | Max droplets | Result |
|---|---|---|---|---|---|---|---|
| 196332_us_ed1 | S. Yuzkli Creek | Bull Trout | BULT | environmental | 6 | 2 | No detection (0 droplets) |
| 196332_us_ed1 | S. Yuzkli Creek | Rainbow Trout | RAIN | environmental | 4 | 0 | No detection (0 droplets) |
| 199190_ds_ed1 | Creek Creek | Chinook Salmon | CHIN | environmental | 2 | 0 | No detection (0 droplets) |
| 203581_us_ed1a | Tributary To Fraser River | Bull Trout | BULT | environmental | 4 | 2 | No detection (0 droplets) |
| 203581_us_ed1a | Tributary To Fraser River | Chinook Salmon | CHIN | environmental | 4 | 2 | No detection (0 droplets) |
| 203581_us_ed1b | Tributary To Fraser River | Chinook Salmon | CHIN | environmental | 4 | 3 | No detection (0 droplets) |
| 203582_us_ed1a | Tabor Creek | Chinook Salmon | CHIN | environmental | 2 | 56 | Detected (≥4 droplets) |
| 203582_us_ed1b | Tabor Creek | Chinook Salmon | CHIN | environmental | 2 | 37 | Detected (≥4 droplets) |
Interactive map
The interactive Fraser eDNA map shows site-level detection results with toggleable per-species layers and an opt-in Controls layer for field blanks. See the interactive Fraser eDNA map.