During the Continental Shelf Multidisciplinary Flux Study (COSMUS) expedition from February to March 2021 aboard RV Polarstern (expedition ID: PS124) (Hellmer & Holtappels, 2021), a large spawning aggregation of notothenioid icefish (Neopagetopsis ionah, Nybelin 1947) was discovered in the southern Weddell Sea. The CCAMLR community was informed of this discovery by Germany in COMM CIRC 22/10 and SC CIRC 22/08 earlier this year (17 January 2022). Purser et al. (2022) report on the spawning aggregation in Current Biology. Here we provide detailed information on the active fish nest aggregation and on additional icefish nesting sites observed in the Filchner Trough area (Knust & Schröder, 2014; Schröder, 2016; Riginella et al., 2021; Purser et al., 2022; Purser et al., in review).