## 3 Results and Discussion
### Analysis of Satellite Images  
Images from the Sentinel-3B OLCI satellite are presented in Figure 6. Data were collected from 91 points and analyzed for CHL_NN (m\({}^{-3}\)), TSM_NN (g m\({}^{-3}\)), and ADG_443_NN (443 m\({}^{-1}\)). The results revealed a high intensity of reflectance at the levels of the analyzed wavelengths. A significant difference was observed between CHL_NN and TSM_NN variables, with a lower level of reflectance for chlorophyll (A) and turbidity (B) in the summer of 2020 as compared to the chlorophyll (C) and turbidity (D) indices in the winter  
Figure 5: Major clusters identified by EDS in the Playa Blanca region contain a high potential of amorphous material with the presence of massive gypsum, rozenit, and melanterite crystals. of 2021 (Figure 6A-D). However, a higher concentration of chlorophyll is noticeable in the summer of 2020 (A), while in winter (B), it is more dispersed (Figure 6A,B). This change in CHL_NN (m\({}^{-3}\)) levels can be explained by average precipitation, as the study area recorded an average monthly precipitation of 20.2 mm and a total of 155 mm throughout the winter (Figure 6B) [8; 30], which is capable of dispersing CHL_NN levels (m\({}^{-3}\)) to more extensive areas [1; 16]. The analysis of the variable ADG_443_NN (443 m\({}^{-1}\)) revealed a high reflectance intensity during the winter of 2021 (Figure 6F), indicating potential for suspended pollution, while in the summer of 2020 (Figure 6E), this index was less pronounced. This shows that the particulate matter dissolved in the waters of Cartagena Bay has a high concentration of NPs, which transport quickly dispersible contaminants to other regions through the action of currents, thus potentially compromising the survival of aquatic biodiversity [16; 21]. In Figure 6, we can observe the existence of a central flow of the waters of Cartagena Bay with high levels of CHL_NN (m\({}^{-3}\)), TSM_NN (g m\({}^{-3}\)), and ADG_443_NN (443 m\({}^{-1}\)) throughout the analyzed period. This is accomplished due to an estuary, where riverine waters meet those of the ocean [18; 21; 53]. Estuaries can transport pollutants and contaminants to marine ecosystems, accounting for the high reflectance levels identified in the three variables analyzed [18; 21]. Studies by [PERSON] et al. [1] and [PERSON] et al. [21] confirm that there is, in general, an increase in levels of contamination of ocean waters in regions formed by estuaries. The general statistical data of this study, related to the collection of information using images from the Sentinel-3B OLCI satellite (Table 2), yielded an R\({}^{2}\) of 0.693. It is noted that the statistical model remains at a good level of reliability, with a Silhouette index of 0.560, indicating that the clusters are classified by a reasonable level of data homogeneity, which allows for more reliable results based on the particularities of the study area [46; 47; 54]. When analyzing Table 2, the individual Silhouette indices of clusters 2 and 3 (0.580 and 0.502, respectively) remain acceptable, while cluster 1 (0.280) remains well below the other clusters. In cluster 1, there are only two collection points, while in clusters 2 and 3, there are 69 and 20 collection points, respectively. This indicates that the greater the number of collection points, the more comprehensive the data grouping will be and, consequently, the more efficient it will be to portray the phenomena within the reality of the study [46; 47; 54]. The Akaike Information Criterion (AIC) demonstrated a total value of 201.860 (Table 2), attributed to the quality of the statistical model used concerning its simplicity [47; 54]. Sequentially, the Bayesian Information Criterion (BIC) reached a value of 247.060 (Table 2), becoming an essential tool aimed at selecting statistical models aimed at better fitting data [47; 54].