Assessment of contaminants, health and survival of migratory shorebirds in natural versus artificial wetlands – The potential of wastewater treatment plants as alternative habitats

The rapid destruction of natural wetland habitats over past decades has been partially offset by an increase in artificial wetlands. However, these also include wastewater treatment plants, which may pose a pollution risk to the wildlife using them. We studied two long-distance Arctic-breeding migratory shorebird species, curlew sandpiper (Calidris ferruginea, n = 69) and red-necked stint (Calidris ruficollis, n = 103), while on their Australian non-breeding grounds using an artificial wetland at a wastewater treatment plant (WTP) and a natural coastal wetland. We compared pollutant exposure (elements and per- and poly-fluoroalkyl substances/PFASs), disease (avian influenza), physiological status (oxidative stress) of the birds at the two locations from 2011 to 2020, and population survival from 1978 to 2019. Our results indicated no significant differences in blood pellet pollutant concentrations between the habitats except mercury (WTP median: 224 ng/g, range: 19–873 ng/g; natural wetland: 160 ng/g, 22–998 ng/g) and PFASs (total PFASs WTP median: 85.1 ng/g, range: