Bioturbation coefficients of deep-sea sediments from the Peru Basin determined by gamma spectrometry of 210Pbexc

In the investigation of the impact of deep-sea mining on the ecosystem, the radioactive disequilibrium between 210Pb and 226Ra was studied in 16 surface sediment cores from the Peru Basin to obtain a quantitative measure of bioturbation. Gamma spectrometry was used as a fast, non-destructive, simultaneous assay of 210Pb and 226Ra. Buried manganese nodules and geochemical anomalies affect the depth profiles of these two radioisotopes. The calculated bioturbation coefficients show a high lateral variability. This made it impossible to detect a significant difference in bioturbation between two different study areas.