FIGURE 4.

Variability in the read numbers of the two target parasite species namely Paramoeba perurans (A,B) and Lepeophtheirus salmonis (C,D) across the different treatments (see Figure 1 for treatment abbreviations). Within each treatment, the reads of each species were compared between the two sequencing methods Illumina (green bars) and Ion Torrent (gray bars) and between filtered and unfiltered marine plankton samples. For the unfiltered (not pre-filtered) water, increasing relative abundances of reads for target organisms are evident as their concentration is increased in the original sample. A similar pattern is not observed for results from prefiltered water. Low levels of cross contamination between the two target species (P. perurans reads in L. salmonis samples and vice versa) are also observed.