Fig. 6

Detection of PRV-1 RNA from water and sediment. A RNA recovery using either ammonium sulfate preservation solution [(NH₄)₂S0₄], Trizol LS, or Qiagen Powersoil total RNA kits were employed on either water or sediment samples. Mean percent recovery of PRV-1 spiked into each sample matrix along with relative qPCR efficiency for detection is presented over a dynamic range of 10⁵–10² copies/sample. The limit of detection (LOD) at which qPCR detection occurred in greater than 80% of technical replicates is also indicated. B Seawater detection prevalence of PRV positive (Pos; detection in both technical replicates), inconclusive (Inc; 1 of 2 technical replicates with Ct > 32) or PRV negative (Neg; no detection in either technical replicates in 40 PCR cycles) test results are presented for sites with net-pen populations of Atlantic salmon where fish in the population had internal tissues that were positive for PRV-1 RNA (PRV+) or where the virus was not detected (PRV-). C PRV-1 RNA estimated copies in PRV positive (Pos; mean copies from two replicates), inconclusive (Inc; copies for the single positive replicate) or PRV negative (Neg; no detection in in 40 PCR cycles) seawater samples that D came from sites located in either the Broughton Archipelago, Clayoquot Sound or Discovery Islands region. Seawater sample volumes of either 10 mL or 0.25 mL are indicated by the size of the data point and the LOD as defined by > 80% consistency in detection is indicated with a dotted line for each sample volume