## 3 Results and Discussion
### Multivariate Analysis Approach  
Two principal factors were obtained from the FA (Table 5) run over the matrix of elements (Cu, Fe, Al, As, Pb, Zn) in water (W), sediments (S) and algae (A), percentage of fine sediments (fines) and the biological responses of the macroalga _L. bertoreana_ (ETR, E\({}_{\rm k}\), \(\alpha\), F\({}_{\rm v}\)/F\({}_{\rm m}\)) and the microalga Chl-\(a\). The relationship between the components and the factors is plotted as an estimated score per station in Figure 4.  
Factor 1 accounted for 82.88% of the total variance, including environmental concentrations of As and its mobility in water, sediments and bioaccumulation, the effect over the microalga population, and the rest of the biological effects. It is also linked to contaminants associated with fine particulate matter of the sediment, As, Pb and Cd, and bioaccumulation of the elements (except Mn) with significant toxic effects. Therefore, Factor 1 is representative of PA and PB, and it is associated more with environmental degradation caused by As (Figure 4, Table 2), which is also reflected by As bioaccumulation in alga tissue and the biomass of microalgae (Table 4). The concentration of As in sediments from PB was eight times greater than the TEL value from the NOAA. However, the concentrations \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **PA** & **PB** & **PC** \\ \hline Ag & mg kg\({}^{-1}\) & 0.10 & bdl & 0.20 \\ Al & mg kg\({}^{-1}\) & 3.33 & 3.67 & 3.00 \\ As & mg kg\({}^{-1}\) & 12.10 & 15.92 & 6.32 \\ Bi & mg kg\({}^{-1}\) & 3.31 & 2.53 & 2.75 \\ Ca & mg kg\({}^{-1}\) & 3087 & 2952 & 2086 \\ Cd & mg kg\({}^{-1}\) & 1.90 ab & 3.94 a & 1.68 b \\ Cu & mg kg\({}^{-1}\) & 2.28 a & 1.28 ab & 0.69 b \\ Fe & mg kg\({}^{-1}\) & 6.10 ab & 7.47 b & 3.03 a \\ K & mg kg\({}^{-1}\) & 14,787 a & 11,430 ab & 10,777 b \\ Li & mg kg\({}^{-1}\) & bdl & bdl & bdl \\ Mg & mg kg\({}^{-1}\) & 2389 & 2189 & 1588 \\ Mn & mg kg\({}^{-1}\) & 0.80 & 0.80 & 0.35 \\ Na & mg kg\({}^{-1}\) & 8271 a & 7106 ab & 6209 b \\ Pb & mg kg\({}^{-1}\) & 1.80 & 1.45 & 6.25 \\ Zn & mg kg\({}^{-1}\) & 2.47 & 1.83 & 0.55 \\ \hline \hline \end{tabular} bdl: below detection limits. Different letters mean significant differences (\(p<0.05\)) with [PERSON]’s multiple comparison test. Absence of letter means no significant difference.  
\end{table} 
Table 4: Concentration of elements in the tissues of _Lessonia bertoreana_ in sampling stations PA, PB and PC. \begin{table}
\begin{tabular}{c c} \hline \hline
**Station** & **Chlorophyll \(a\) (ug mL\({}^{-1}\))** \\ \hline PA & 0.006675 \(\pm\) 0.0017 * \\ PB & 0.013502 \(\pm\) 0.0047 \\ PC & 0.016339 \(\pm\) 0.0001 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Chlorophyll \(a\) concentration of the upper stratum of the water column of three study sites (Asterisk indicates significant difference (\(p\leq 0.05\))). of other metals in alga tissues included in this factor, such as Fe, Cd, Mn and Zn, are also associated with the granulometry. Factor 2, which accounted for 12.45% of the total variance, resulted in the combination of contamination by certain metals; only relations with the partition in the sediment of the Zn were included, as the rest had no influence (or minimum) with metal concentrations. There was a slight Cu accumulation, which is not appreciable compared to the bioaccumulation for the rest of the elements (except for Mn, which is not important from the point of view of contamination and the geochemical matrix). The biological effects were not significant in Factor 2. Therefore, Factor 2 is not associated with the toxicity of metals in water when there are negative values for PB and PC, and possibly also for PA, due to low values (Figure 4). Figure 4: Scores of each factor for the sampling stations.