COAST IMPACT was a research project funded by the Norwegian Research Council from August 2020 to December 2024. The main aim of the project was to investigate the influence of pollution and infectious diseases on shorebirds that migrate along the East Asian–Australasian Flyway (EAAF).

Recommendations

Introduction

Globally, coastal ecosystems are undergoing rapid changes with respect to habitat degradation and pollution, which is especially true along the East Asian coastline due to rapid industrial and urban development. This has led to effects on coastal wetlands in terms of biodiversity and also on the quality of the stopover sites for migrating birds, such as shorebirds.

Shorebird populations are declining at an alarming rate along the East Asian Australasian flyway, the reasons for which are mostly unknown. Besides habitat degradation, pollution is suspected to play a role in these declines. One way that pollutants might decrease survival during migration may be through effects on the immune system that can affect the susceptibility to infectious diseases. Pollution has indeed been related to the outbreaks and increase in infectious disease as early as the 1960s in both animals, including birds, and humans. 

Aim

In this project, we have studied the impact of pollution in combination with food quality and infectious disease (i.e. avian influenza) on migrating shorebirds, with a specific focus on pollution picked up in Chinese coastal wetlands used as stop-over sites during migration. 

Results

We have analysed benthic and sediment samples collected along the Chinese coast  for both legacy and emerging organic pollutants and identified Bohai bay as a hot spot for pollutant  exposure to the shorebirds during migration. 

We have also analysed pollutants in shorebirds from Australia and along the Chinese coast (Ross et al. 2024a,b, Zhang et al, 2025), including the so called "forever chemicals" (PFAS). We have found that there are many more PFAS present in shorebirds than can be found by normal targeted analysis, and especially high concentrations of PFAS precursors were found in the liver after TOPA (total oxidisable precursor assay)  analysis, with up to 180 times higher concentrations of PFAS than could be detected before (Zhang et al. 2025).

We have also identified some potential biomarkers for effects in shorebirds and ducks (oxidative stress and specific micro RNAs; Brand et al. 2025, Ross et al. 2023). In addition, in an experimental egg injection study with PFAS in mallard ducks, we observed sex-specific effects on immune and metabolism gene expression, with changes most pronounced in males. This underscores the need for further research to understand the specific mechanisms induced by PFAS exposure. Our results also highlight the developmental risks of maternal PFAS transfer, potentially affecting the fitness of wild avian species.

Lastly, we have identified mercury as a potential threat to several shorebird populations (Ma et al. 2024) and found that well managed artificial wetlands could provide useful alternative habitats for shorebirds to rest and feed (Ross et al. 2023).

Videos

PhD candidate Anne-Fleur Brand studies the combined influence of pollution and infectious diseases on EAAF shorebirds.

Postdoc Dr. Junjie Zhang studies the detection and analysis of pollutants in samples from EAAF shellfish, shorebirds and coastal sediments.

Impact

The impact of the project’s results for the scientific community and risk assessment are very important, as we identified several hot spot areas along the Chinese coast. In addition, our results indicated that there may be many more PFAS to consider than are currently included in routine monitoring. As a result, there is likely a much higher exposure (and associated health) risk to wildlife due to PFAS.

Recommendations

The following highlights and recommendations can be made as a result of this project:

1. Current targeted PFAS analysis does not cover the exposure risk. TOPA or other types of analysis need to be employed to expand our measurement of PFAS exposure.
2. The contamination with other pollutants such as chlorinated paraffins and pesticides and pharmaceuticals needs to be investigated.
3. Contamination with legacy POPs, such as PCBs, organochlorine pesticides and PBDEs is relatively low in the foraging places (sediment), diet (shellfish) of the shorebirds and in the birds themselves
4. miRNA research in wildlife has only recently started and many questions remain. Especially, the use of blood presents many challenges.
5. Population culling of the most contaminated birds may result in the birds being sampled representing the less contaminated ones. It may be preferable to investigate concentrations in dead birds along the flyway.
6. The contamination of artificial wetlands should be monitored and managed to ensure the wetlands can provide alternative habitats for the shorebirds, in the face of widespread habitat loss in the flyway.

Publications so far

Brand, A., Waugh, C.A., Fernandes, J.M.O., Klaassen, M., Wille, M., Jaspers, V.L.B. and Andreassen, R. (2025), Circulating miRNAome of avian influenza-infected ruddy turnstones Arenaria interpres. J Avian Biol, 2025: e03404.

Ma, Y., Choi, C.-Y., Shang, L., Klaassen, M., Ma, Z., Chang, Q., Jaspers, V.L.B., Bai, Q., He, T., Leung, K. K.-S., Hassell, C. J., Jessop, R., Gibson, L. (2024). Mercury contamination is an invisible threat to declining migratory shorebirds along the East Asian-Australasian Flyway. Communications Biology 7(1), 585.  DOI: 10.1038/s42003-024-06254-x

Ross, T.A., Zhang, J., M Wille, Ciesielski, T.M., Asimakopoulos, A. G., Lemesle, P., Skaalvik, T. G., Atkinson, R., Jessop, R., Victorian Wader Study Group, Jaspers, V. L. B., Klaassen, M. (2023). Assessment of contaminants, health and survival of migratory shorebirds in natural versus artificial wetlands – The potential of wastewater treatment plants as alternative habitats. Science of the Total Environment 904, 166309. 

Ross, T. A., Zhang, J., Chiang, C. Y., Choi, C. Y., Lai, Y. C., Asimakopoulos, A. G., Lemesle, P., Ciesielski, T.M., Jaspers, V.L.B. & Klaassen, M. (2024a). Running the gauntlet; flyway-wide patterns of pollutant exposure in blood of migratory shorebirds. Environmental Research, 246, 118123.

Ross, T. A., Zhang, J., Skaalvik, T. G., Atkinson, R., Jessop, R., Asimakopoulos, A. G., Jaspers, V.L.B., Klaassen, M. (2024b). Per-and poly-fluoroalkyl substances (PFAS) do not accumulate with age or affect population survival in ruddy turnstone (Arenaria interpres). Science of The Total Environment, 955, 176790.

Zhang, J., Cioni, L., Jaspers, V.L.B., Asimakopoulos, A. G., Peng, H. - B., Ross, T. A., Klaassen, M., Herzke, D. (2025). Shellfish and shorebirds from the East-Asian Australian flyway as bioindicators for unknown per- and polyfluoroalkyl substances using the total oxidizable precursor assay. Journal of Hazardous Materials, 487, 137189.

International media

PFAS: Found 180 times more ‘forever chemicals’ in birds

PFAS: 180 Mal mehr "ewige Chemikalien" in Vögeln gefunden (in German)

PFAS : 180 fois plus de "produits chimiques éternels" chez les oiseaux (in French)

PFAS: halladas 180 veces más "sustancias químicas para siempre" en aves (in Spanish)

Phys.org

Bird study finds much larger volumes of toxic PFAS chemicals than previously reported

Researchers explore microRNA's role in bird flu infection

Norwegian SciTech News

Can the stuff in cells we thought was junk help us understand virus reactions?

Why a groundbreaking discovery about tiny RNA molecules may be helpful for humans and wildlife

Laboratory Equipment

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