Figure 4. Alpha diversity metrics boxplot of sites by sources.
Overall, differences in microbial community structure were observed
between seawater, sediment, skin, and midgut samples collected from
different sites. Microbial communities from different sources were all
distinct from one another (Table 2), although skin and midgut samples
clustered closer together (Figure 5A). However, these similarities
between skin and midgut microbiota composition varied across sites
(Table 3). A deviation of seawater microbiota in Starfish Bay could be
observed along PC2, away from the two other sites (Figure 5A). Community
structure showed a high influence on the interaction between source and
site factors as can be seen in the clustering tendency of the samples
(Figure 5A). A general higher to lower dispersion trend in beta
diversity from highly polluted to low polluted sites was observed in
seawater and sediment samples. On the other hand, dispersion patterns in
hosts across the three sites did not align with that of the
environmental sources. In midgut samples, a general trend of higher beta
diversity dispersion in the least polluted site was observed (Figure 5B,
Table 3).