Table 5-5: Species overall dominance. Percent of individuals in each sample. 



The communities within the upper and central Rincon 

 Bayou treatment sites were dominated by a few 

 common species, evidenced by the stations clustering 

 together on the first axis of the principal component 

 analysis (TCA) (Figure 5-10). The PCA 1 axis, or first 

 principal component (PCI), explained 70% of the 

 variance in the data set, and PCA 2 axis (PC2) 

 explained an additional 19% of the variance. The 



dominant organisms Streblospio benedicti (Sb), Laeonereis 

 culveri (Lc), unidentified Ostracoda (Os) and 

 Chironomid larvae (Ch) drove the trend for PC 1 

 toward high positive values because they were part of 

 the average dominant commumty (Figure 5-lOa). 

 Thus, all stations had high PCI values (Figure 5-lOb). 



5-16 



Benthic Communities 



