The characterization and quantification of exposure to chemical pollutants is essential to understand and predict the possible effects on aquatic organisms’ biology and physiology.  Here we investigated a novel approach to estimate the concentration of labile metal contaminants in saltwater over a set time-frame. Diffusive Gradient Thin-film (DGT) sampling units have been used to quantify metals concentration from a groundwater source in a tidal inlet of South Australia. DGTs ability to capture pollutants concentration relies on a resin with a constant absorption rate for specific chemicals. DGT units were deployed at three depths (surface, mid-water and bottom) across 23 locations. Deployment occurred for a period of two to seven days which allowed us to test for saturation of the resin and bio-fouling formation on the units. Each deployment was matched with surface water samples for comparison. No differences were found between dissolved metal concentrations in water samples and labile metals in DGTs. Nonetheless, no bio-fouling was observed, and saturation did not occur for up to five days. Ultimately the results suggested that DGTs provide reliable data on time weighted average of labile metals and represent an innovative and useful tool to quantify exposure of fish and other aquatic organisms.