Deep-sea ecosystems are highly sensitive to changes in organic matter export and oxygenation driven by climate change. Here we document past ecological changes in benthic foraminiferal assemblages indicative of deglacial changes in deep-sea oxygenation and the character of organic matter fluxes from sedimentary records retrieved at intermediate (692 m) and abyssal (3667m) depths in the Gulf of Alaska. Constrained multivariate ordination combining faunal and geochemical data over the past ~22,000 years distinguishes the impacts of pulsed productivity, which exports carbon to the abyss, from extreme dysoxia across the deglacial warming transition. At both depths, opportunistic species are more prevalent in interglacial conditions, reflecting higher pulsed organic matter export to the seafloor developed in response to warming and reduced sea-ice cover. Benthic foraminiferal species tolerant of low-oxygen conditions increased in abundance during the deglacial transition at both intermediate and abyssal depths. Authigenic trace metals reveal sulfidic sedimentary conditions indicative intermittent anoxia, but only at intermediate-depths. Benthic foraminiferal richness and evenness are also highest during this deglacial low-oxygen interval, likely due to high food availability. Last Glacial Maximum faunas were distinctly different at the two sites, consistent with a more stratified deep Pacific, but the faunas become more similar during Holocene time, suggesting destratification of the abyss during deglaciation. These ecosystem responses support that carbon fluxes increased during warm intervals in subpolar regions and underscores the importance of considering the effects of transient biological blooms on paleoceanographic interpretations and in model projections of future deep carbon export.

深海生态系统对气候变化驱动的有机物出口和氧合作用变化高度敏感。在这里，我们记录了过去的底栖有孔虫群落生态变化，这些变化指示了深海氧化作用的冰川变化以及阿拉斯加湾中层（692 m）和深层（3667m）深度的沉积记录中的有机质通量特征。在过去的约22,000年中，结合动物和地球化学数据进行的受约束的多元排序将脉冲生产力的影响（其将碳输出到深渊）与整个冰川期变暖过程中的极端营养不良区分开来。在这两个深度，机会物种在冰间条件下都比较普遍，反映出由于变暖和海冰覆盖减少，向海底输出的脉冲有机物增多。底栖有孔虫物种对低氧条件的耐受性在中冰期和深海深度的冰期转变过程中都增加了。自生的痕量金属显示出硫化物沉积条件，指示间歇性缺氧，但仅在中间深度。在这个冰期低氧间隔期间，底栖有孔虫的丰富度和均匀度也最高，这可能是由于食物供应量较高。在这两个地点，最后一次冰川最大动物区系明显不同，这与更分层的深太平洋相符，但是在全新世时期这些动物区系变得更加相似，这表明冰消过程中深渊已被破坏。