Arctic seabirds contaminate springtails and damage their DNA
Silje Marie Kristiansen, Biosciences
Seabirds feed high in the food chain and due to biomagnification their bodies contain high concentrations of many anthropogenic contaminants. In the Arctic they have been shown to function as important biovectors of contaminants from ocean to land. The tundra near bird cliffs is heavily influenced by nutritious and contaminant-enriched guano and is generally characterised by rich and diverse vegetation. In these areas, springtails (Collembola) contribute to a high proportion of the soil fauna biomass. They play a vital role in soil ecosystem processes such as decomposition and mineralization.
The aim of this study was to determine the exposure, accumulation and effects of seabird-derived contaminants on springtails. Springtails and their habitat (soil/moss) were sampled in sites of high, medium and low seabird influence in Svalbard, and analysed for a wide range of organic contaminants, mercury (Hg), and stable isotope ratios of nitrogen (δ15N).
We also quantified DNA strand breaks in springtail cells. Seabird influence (indicated by δ15N) and contaminant concentrations were indicated to be higher in soil/moss sampled closer to the bird cliff (0–150 m), compared to further away (250–400 m). Contaminant concentrations in Collembola were dominated by Hg, followed by hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs) or polybrominated diphenyl ethers (PBDEs), and chlordanes (CHLs). DNA fragmentation was higher in Collembola from sites with high seabird influence, compared to sites with medium and low. DNA damage may be an effect from exposure to seabird-derived contaminants, or physico-chemical changes in the soil from high input of seabird guano.