Fig. 2: Sea ice particulate organic carbon (iPOC) content representing 159 Arctic consumers relative to phytoplankton.

Species-binned HBI-based estimates of sea-ice carbon content for all individuals (n = 2251) sampled between 1982–2019 and grouped by major taxa including a benthic invertebrates sorted by feeding strategy (red text), b zooplankton and ice-associated invertebrates, c fish, and d seabirds and marine mammals, color-coded by habitat. 50% iPOC% (red-dashed line) is the minimum threshold to indicate that an organism recently obtained a significant proportion of their carbon from directly consuming sea ice algae or fed on organisms that rely heavily on ice algae prior to sampling. Box plots display the first to third quartiles with the vertical line representing the median values, the whiskers extend to the minimum and maximum values, and points represent outliers.