3.1.1. Water

Near-bottom water temperature and salinity were homogeneous throughout the lagoon averaging 22.6 ± 0.2 ◦C and 29.9 ± 0.3 psu (± SE standard error), respectively. Marked spatial variation was found for all the other environmental variables examined (Figure 2). In particular, ammonium, RP, BOD5, CODMn, and Chl-*a* concentrations were highest at site F, while nitrate, nitrite and DIN concentrations, and the N/P ratio were lowest at site A. SS concentrations were lowest at both site A and B. Overall, the water variables highlighted the hypertrophic condition of site F, in the innermost sector of the lagoon, as compared to all the other sites. Separation of sites was also clearly revealed by PCA, as site F was separate along the *x*-axis, and sites A and B along the *y*-axis (Figure 3). The PCA loadings showed the highest correlation for ammonium, RP, BOD5, CODMn, and Chl-*a* (positive), and DO (negative) on the *x*-axis, and the highest (positive) correlation for nitrate, nitrite DIN, N/P, and SS on the *y*-axis (Table 2).

**Figure 2.** Mean value (n = 3; ±SE standard error) of near-bottom water variables at each site: ammonium, nitrate, nitrite, dissolved inorganic nitrogen (DIN = ammonium, nitrate, and nitrite), reactive phosphorous (RP), N/P, dissolved oxygen (DO), biological oxygen demand (BOD5), chemical oxygen demand (CODMn), chlorophyll-*a* (Chl-*a*), and suspended solids (SS).

**Figure 3.** Principal component analysis (PCA) of near-bottom water variables, including salinity, dissolved oxygen (DO), ammonium, nitrate, nitrite, dissolved inorganic nitrogen (DIN = ammonium, nitrate, and nitrite), reactive phosphorus (RP), N/P ratio, suspended solids (SS), biological oxygen demand (BOD5), chemical oxygen demand (COD5), and chlorophyll-*a* (Chl-*a*). PC1 = 46.5% of variance, PC2 = 34.4% of variance.



In bold, the highest loadings.
