Fig 4. Percent positive detections and relative DNA copy number for Northern pike cage experiments.

Percent positive detections (filled bars) and relative DNA copy number (unfilled, box plots) for Northern pike cage experiments in Denise (a), Gensle (b), Little Bear (c) and Tiny (d) Lakes near Soldotna, AK. For the box plots, the dark horizontal line represents the mean, with the box representing the 25^th and 75^th percentiles and the whiskers the 5^th and 95^th percentiles. Water samples (n = 8 per lake treatment) were analyzed for Northern pike DNA prior (Pre) to introduction of caged Northern pike and then 7 days after introductions at 1 m, 10 m, and 40 m away from each cage.