Table 1. Samples by site and tide, showing balanced sampling design.

Each site (N = 3) had a total of four sampling events (time points), consisting of three water samples per event, and then 3–4 PCR replicates per water sample, such that we sequenced 36–44 individual PCR replicates per geographic sampling site. 35 of 36 samples were successfully processed, with 93 individual replicates survived quality-control, described below.

	Incoming tide	Outgoing tide
Lilliwaup	5	6
Potlatch	6	6
Twanoh	6	6