Plastic pollution is a ubiquitous and increasing problem in the world's oceans, but the health effects of microplastics on animals remains poorly known.
A new study, published in Journal of Hazardous Materials, has demonstrated the impacts that ingesting such materials can have on seabirds.
The researchers investigated the presence and impact of microplastics in multiple tissues from Flesh-footed Shearwater, a species that ingests considerable quantities of plastics, and used techniques to measure physiological responses and inflammation from the plastics.
Examining the kidney, spleen and proventriculus (part of the stomach), the team found that each of these organs had embedded microplastic particles and this correlated with macroplastic exposure.
Considerable tissue damage was recorded. In the proventriculus, the team found evidence of low water content, redness and loss of epithelial tissue structure. More ingested plastic also meant less stomach rugae – the ridges in the stomach that increase surface area and help absorb nutrients. Tubular glands that produce mucus and protect the stomach lining were also less abundant.
As well as this, they found evidence of inflammation, fibrosis, and loss of organ structures in the kidney and spleen.
This demonstrates that plastic causes harm not only at the time of ingestion, but over weeks and months afterwards in different tissues, at different temporal and spatial scales. The results of the investigation indicate the scope and severity of the health impacts of plastic pollution may be grossly underestimated on seabirds.
Rivers-Auty, J, Bond, A L, Grant, M L, & Lavers, J L. 2022. The one-two punch of plastic exposure: Macro- and micro-plastics induce multi-organ damage in seabirds. Journal of Hazardous Materials. DOI: https://doi.org/10.1016/j.jhazmat.2022.130117