Ecosystem uptake and transfer of Sellafield-derived radiocarbon (¹⁴C) part 2: The West of Scotland

Highlights

• Radiocarbon (¹⁴C) uptake and transfer examined for the West of Scotland marine ecosystem.

• Dissolved inorganic carbon (DIC) enriched in ¹⁴C at sites remote from Sellafield.

• Enriched ¹⁴C activities in biota as a result of trophic transfer through the food web.

• Transport of Irish Sea water enriched in ¹⁴C key to West of Scotland enrichment.

• Similar activities relative to the western Irish Sea are observed.

Abstract

Ecosystem uptake and transfer of Sellafield-derived radiocarbon (¹⁴C) were examined within the West of Scotland marine environment. The dissolved inorganic carbon component of seawater, enriched in ¹⁴C, is transported to the West of Scotland where it is transferred through the marine food web. Benthic and pelagic biota with variable life-spans living in the North Channel and Clyde Sea show comparable ¹⁴C activities. This suggests that mixing of ¹⁴C within the Irish Sea results in a relatively constant northwards dispersal of activity. Benthic species in the Firth of Lorn have similar ¹⁴C enrichments, demonstrating that Irish Sea residual water is the dominant source to this area. Measured ¹⁴C activities in biota show some similarity to western Irish Sea activities, indicating that dispersion to the West of Scotland is significant with respect to the fate of Sellafield ¹⁴C releases. Activities measured in commercially important species do not pose any significant radiological risk.