Ingested plastic and trace element concentrations in Short-tailed Shearwaters (Ardenna tenuirostris)

Area of Science:

• Marine biology
• Environmental toxicology
• Avian ecology

Background:

• Marine pollution, particularly plastic debris and associated chemicals, poses a significant threat to complex marine trophic systems.
• Anthropogenic stressors like plastic ingestion can harm wildlife, necessitating investigation into their physiological impacts.

Purpose of the Study:

• To investigate the relationship between plastic ingestion and trace element burden in the breast muscle of Short-tailed Shearwaters (Ardenna tenuirostris).
• To assess temporal trends in plastic ingestion and trace element concentrations in this sentinel species.

Main Methods:

• Analysis of plastic ingestion (mass and number of items) and trace element concentrations (Cu, Zn, As, Rb, Sr, Cd) in breast muscle tissue of Short-tailed Shearwaters.
• Comparison of data from 1969-2017, including comparisons with limited prior study data.

Main Results:

• No significant relationship was found between the amount of plastic ingested and trace element concentrations in the birds' tissues.
• While the mass and number of ingested plastic items did not change significantly over the study period, concentrations of several trace elements (Cu, Zn, As, Rb, Sr, Cd) showed an apparent increase in birds sampled in 2017 compared to historical data.
• This suggests a potential increase in bioavailable trace elements in the marine environment.

Conclusions:

• Plastic ingestion by Short-tailed Shearwaters does not directly correlate with their trace element burden.
• The observed increase in certain trace elements over time, despite stable plastic ingestion, highlights the utility of this species as a sentinel for monitoring anthropogenic alterations in the marine environment.
• Policy decisions should consider data from sentinel species like the Short-tailed Shearwater to track marine environmental changes.