We investigated the microhabitats of benthic foraminifera and stable oxygen and carbon isotope compositions of living (stained) Elphidium batialis Saidova off Hidaka (northern Japan) in the Northwestern Pacific continental margin. In the study area, six major species reside in three microhabitats that are vertically distributed within the sediment column. Bolivina spissa, Uvigerina akitaensis, and E. batialis tend to be shallow infauna, whereas Chilostomellina fimbriata and Globobulimina pacifica are deep infauna. Nonionellina labradorica is intermediate infauna. The δ¹⁸O values of E. batialis and U. akitaensis increased gradually with the water depth, but those of E. batialis contain a systematic offset by about −1.0 to −1.2‰ to U. akitaensis. This offset range is consistent with that observed in previous fossil studies in the Bering Sea. The δ¹³C values of U. akitaensis are approximately consistent (−1.1‰ to −0.8‰) with the water depth, whereas those of E. batialis increase with water depth from the shallower sites (−3.0 to −2.0‰) to the deeper sites (−2.0 to −1.6‰). Depending on the water depth, the δ¹³C values of E. batialis are lower than U. akitaensis by −1.4 to −0.7‰. Elphidium batialis may produce slightly ¹³C-poor calcite at the severely oxygen-poor water depths of the oxygen minimum zone (OMZ), suggesting that dissolved oxygen level may affect δ¹³C values of E. batialis during calcite precipitation. It is hypothesized that the δ¹³C values of E. batialis may contain signals arising from food digestion (or an internal respiration effect) and change the proportion of carbonate ions for calcite precipitation between the DIC values of the ambient pore water and food materials, depending on the dissolved oxygen level on the seafloor. Thus, the δ¹³C difference between E. batialis and Uvigerina spp. might be useful when inferring the past development of the OMZ and/or changes in the evolution of the North Pacific Intermediate Water in the subarctic North Pacific margin including adjacent marginal seas such as the Bering Sea.

我们调查了西北太平洋大陆边缘日田以外（日本北部）的生活（染色）鳞翅目小夜蛾Saidova的底栖有孔虫的微生境以及稳定的氧和碳同位素组成。在研究区域中，六个主要物种生活在三个微生境中，这些生境垂直分布在沉积物中。Bolivina spissa，Uvigerina akitaensis和E. batialis往往是较浅的动物，而Chilostomellina fimbriata和Globobulimina pacifica是较深的动物。Nonionellina labradorica是中间动物。的δ ¹⁸的O值E. batialis和U. akitaensis与水的深度逐渐增加，但这些的E. batialis包含一个系统由大约-1.0至-1.2‰偏移U. akitaensis。该偏移范围与先前在白令海进行的化石研究中观察到的范围一致。所述δ ¹³的C值U. akitaensis大致一致（-1.1‰至-0.8‰）与水的深度，而那些的E. batialis从较浅部位水深（-3.0至-2.0‰）增加至较深的部位（-2.0至-1.6‰）。根据水深度，δ ¹³的C值E. batialis是低于U. akitaensis由-1.4至-0.7‰。蝙蝠phi可以产生略微¹³在最低含氧带（OMZ）的严重贫氧水深度C-差方解石，表明溶解氧水平可影响δ ^13个的C值E. batialis方解石沉淀过程。据推测，所述δ ¹³的C值E. batialis可以含有从食物消化所产生的信号（或内部呼吸效应）并改变碳酸根离子的比例为方解石沉淀环境孔隙水和食物材料的DIC值之间，取决于海底的溶解氧水平。因此，δ ¹³ C之间差E. batialis和Uvigerinaspp。在推断OMZ的过去发展和/或北极北太平洋边缘（包括邻近边缘海，如白令海）的北太平洋中间水的变化时，可能有用。