Insights into Copper Hazards and Species Sensitivity in Freshwater and Saltwater Ecosystems

Over the past few years, copper (Cu) has been considered the contaminant posing the greatest risk in aquatic environments. This study, therefore, aimed to evaluate species sensitivity and Cu hazards to aquatic organisms in freshwater and saltwater ecosystems. The results showed that there was no significant difference in Cu hazards between the two environmental matrices, with 5% hazardous concentrations (HC₅s) of 6.21 µg/L for freshwater organisms and 9.42 µg/L for saltwater counterparts. However, obvious differences were observed among taxonomic groups; for instance, freshwater algae exhibited the highest sensitivity (HC₅ = 0.93 µg/L), whereas marine fish showed the greatest tolerance (HC₅ = 39.75 µg/L). These findings provide valuable insights into Cu hazards and associated ecological risks, thereby guiding water quality management and strategies to safeguard aquatic ecosystems from Cu contamination.