Assessment of water quality and emerging pollutants in two fish species from the mallorquin swamp in the Colombian Caribbean.

The Mallorquín Swamp, an important ecosystem in Atlántico, Colombian Caribbean, underwent environmental monitoring at eight points during rainy, transition, and dry seasons. This was to assess water quality, seasonal variation, and the bioaccumulation of metals, emerging pollutants, and organic compounds in the fish and . Water parameters were analyzed using descriptive statistics and multifactorial ANOVA with the Tukey HSD test for seasonal differences. Normality and variance of the fish results were verified, and differences between groups were evaluated using ANOVA or Kruskal-Walli's method when data transformation failed. Spearman correlation was used to relate the results. Water sampling revealed variations in temperature, dissolved oxygen, salinity, and nutrient levels. Significant differences in alkalinity and hardness were observed across seasons and sample points. The most probable number (MPN) levels of Total coliform and peaked near areas with domestic wastewater inputs, reaching 5.4x10 and 4.0x10 MPN, respectively, indicating potential microbiological contamination of water. Fish samples revealed high concentrations of persistent substances such as methylmercury, polycyclic aromatic hydrocarbons (PAHs), and emerging pollutants. Heavy metal analysis showed elevated iron levels (5.28 ± 0.657 mg/L), while emerging pollutants, including ibuprofen (218 μg/L) and naproxen (343.89 μg/L), exhibited high concentrations near human settlements. showed higher bioconcentration tendencies for methylmercury (238.5 ± 100 μg/kg), and acenaphthene (7782 ± 4123.8 μg/kg), possibly influenced by its feeding habits and habitat preferences. In contrast, exhibited higher bioaccumulation trends of PAH (2376.23 ± 599.63 μg/kg acenaphthene) and emerging pollutants like galaxolide (139.49 ± 34.98 μg/kg), possibly due to its mobility and exposure to various contaminants in their environment. These findings emphasize the need to monitor and manage aquatic ecosystems' health to mitigate anthropogenic influences on water quality and biodiversity. This research serves as a reference for global conservation efforts, emphasizing the need for comprehensive monitoring and regulatory frameworks to protect aquatic environments and ensure their sustainability for future generations.