Optimal filter pore size
We found 1 µm PCTE filters had the highest number of intracellular eDNA
copies (mean: 970,000), with the mean number of copies descending to
937,000 for 3 µm, 801,000 for 8 µm, 762,000 for 5 µm, and the fewest
copies detected with 10 µm (596,000). We found the 95% confidence
intervals of all but the 10 µm filters overlapped the zero line when
assessing the deviation from global mean (Figure 3 ),
and there was no significant difference in copy number among different
pore size categories using averaged data from qPCR technical replicates
(F4,15 = 0.34, p = 0.84). We found a non-significant
decrease of ~37,500 copies per µm increase in filter
size when we treated filter pore size as a continuous variable (beta =
37,479, 95% CI = [-105,214, 30,257]; p = 0.26).