Faecal pellets and eggs of Antarctic silverfish have been collected over the seasons using a sediment trap deployed on 1998 in Terra Nova Bay, Ross Sea, Antarctica in the frame of the National Italian Antarctic Research project (PNRA). Antarctic silverfish (ASF) accounts for over 90% of the local fish communities in the Southern Ocean costal area. Samples have been investigated in order to quantify the contribution of fish faecal pellets and eggs to the export of carbon. Funding: CLIMA project (Climatic Long-term Interactions for the Mass Balance in Antarctica) of the Italian National Program for Research in Antarctica.

The quantities of key biologically active elements, carbon, nitrogen, and hydrogen, were measured from batches of eggs from the Antarctic Krill, Euphausia superba. These krill were collected in the "Western Core Box" krill time series region, an area to the north-west of South Georgia, on the RRS James Clark Ross research cruise JR17002 in the summer (January) 2018. Eggs were collected from ship board incubation experiments. Maternal parasite assemblage and load was determined using DNA metabarcoding. Krill with higher loads of apicomplexa and ciliate parasites laid eggs with lower quantities of carbon and nitrogen. These lower quality eggs may have lower survival and recruitment success, suggesting a mechanism by which parasites may influence krill population dynamics. Funding source: This research was supported by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 887760 (ParaKrill).