Figure 1: Interannual variability of multiple trophic levels of the Palmer Station food web and linkages between them.
From: Winter and spring controls on the summer food web of the coastal West Antarctic Peninsula
(a) Summer (December–January–February) depth-integrated (0–50 m) chlorophyll-a (chl-a) and bacterial productivity (BP) anomalies pooled from Palmer Stations B and E for the PAL-LTER time series, 1991–2012 (see Methods section). The average combined (Stations B and E) depth-integrated chl-a and BP for the time series is 108 mg m−2 and 32.4 mg C m−2 d−1, respectively. (b) Size-class distribution (percent contribution (colours; see legend) of each krill size bin (y axis)) of Antarctic krill, E. superba, in Adélie penguin diet samples, 1988–2012; modified with permission from Ducklow et al.25 The vertical red arrows indicate the appearance of strong new krill cohorts in years following positive chl-a anomalies.
