Search for a command to run...
Bottlenose dolphins (Tursiops truncatus) that reside in nearshore coastal waters may be exposed to natural and anthropogenic trace elements (TEs) that are conveyed by freshwater discharge and pose toxicity risks. The links between freshwater discharge and potential TE exposure in dolphins have not been clearly established. This study examined the relationships between freshwater discharge, environmental variables and a suite of TEs in water and dolphin skin, collected year-round in Mobile Bay, Alabama. TEs in water exhibited seasonal and spatial variability, with higher concentrations in fall and summer months and at more southern sites, distal to major sources of input. In dolphins, a notable lag in TE accumulation was observed, with skin concentrations peaking approximately four to five months after water TE levels were highest. Correlations were observed between concentrations in water and dolphins for aluminum (Al), strontium (Sr), uranium (U), and vanadium (V), suggesting a more direct uptake pathway for these elements compared to others. Overall, TE variability was high in water and dolphins, likely reflecting seasonal and site-specific differences as well as individual differences in dolphin diet, movement and metabolism. These results highlight the changes in freshwater input and complex environmental interactions driving TE mobilization and bioaccumulation. Future studies could incorporate expanded geographic sampling, prey analysis, and long-term monitoring to establish baseline concentrations, evaluate physiological impacts, and assess broader ecosystem implications.