Capturing millennial-scale resilience of Antarctic deep-sea habitats by testing the Food Bank Hypothesis persistance

Understanding the long-term stability of ecosystems is a central challenge in Earth system science, particularly in polar regions where environmental change is rapid and often nonlinear. Antarctic marine ecosystems experience extreme seasonality in surface primary productivity, yet benthic communities frequently display remarkable persistence through time. The Food Bank Hypothesis offers a compelling explanation for this paradox, proposing that a reservoir of fresh organic matter stored in seafloor sediments buffers benthic ecosystems from short-term variability in pelagic production. Although supported by modern observations and process studies, this hypothesis has never been evaluated across major climatic transitions, limiting our ability to assess its relevance under future change. Here, we provide the first long-term test of the Food Bank Hypothesis by exploiting marine sediment cores as natural archives of Antarctic ecosystem dynamics. We analyzed parallel Holocene records of diatoms and benthic foraminifera from multiple sites along the Antarctic Peninsula, a region that has experienced pronounced climate variability since the last deglaciation. By comparing changes in community composition, diversity, and temporal coherence between these two ecological compartments, we identify contrasting response pattern. Our results reveal that pelagic ecosystems responded to climate variability in a largely linear and coherent manner, while benthic communities were characterized by extended intervals of compositional stability interrupted by abrupt, nonlinear regime shifts, indicative of a highly resilient system buffered against external forcing. Furthermore, benthic assemblages showed reduced temporal coherence among sites relative to diatoms, highlighting the role of local conditions in modulating the timing and expression of externally driven change. These findings provide strong paleoecological support for benthic food banks as a persistent and foundational component of Antarctic marine ecosystems. More broadly, they demonstrate the power of integrating microfossil records across ecological compartments to resolve ecosystem resilience, thresholds, and tipping points dynamics.