In this study we used compound-specific carbon isotope analysis of amino acids (δ¹³C_AA) to determine organic carbon sources utilized by the dominant benthic bivalve species collected along a latitudinal gradient in the northern Bering and Chukchi Seas, specifically at productivity hotspots identified within the Distributed Biological Observatory (DBO) program, and over Hanna Shoal in the northern Chukchi Sea. The recent shift to earlier sea-ice melt is one of the climate change consequences influencing Pacific Arctic ecosystems, which we integrate within our observations. Our goals included investigating the utilization of organic matter resources by several dominant Arctic bivalves and their trophic elasticity to changes in primary productivity patterns following changes in the onset of the annual productive season. Based upon δ¹³C_AA patterns observed, these species utilized different carbon sources along the latitudinal gradient, including a strong input of bacterially reworked material and microalgae, mainly in particulate organic matter mixtures. Species type and the sampling location both played roles in δ¹³C_AA variability, suggesting the influence of local production and decomposition processes. Macoma calcarea and Ennucula tenuis were shown to utilize organic matter of different quality, suggesting they may switch their feeding preferences to more detrital sources on a seasonal basis, but this was also affected by geographical location. These observations may have important implications for the benthic populations as microbial reworking of organic material is expected to increase with climate warming and likely shifts in food web structure.

在这项研究中，我们使用的氨基酸的特定化合物的碳同位素分析（δ ¹³ C ^ _AA）确定北部白令海和楚科奇海沿纬度梯度收集的主要底栖双壳类物种利用的有机碳源，特别是在分布式生物观测站（DBO）计划中以及楚科奇海北部汉纳浅滩上确定的生产力热点。最近向更早的海冰融化转变是影响太平洋北极生态系统的气候变化后果之一，我们将其纳入我们的观察之中。我们的目标包括调查几个主要北极双壳类动物对有机物资源的利用及其在年度生产季节开始变化后对初级生产力模式变化的营养弹性。基于δ ¹³ C ^ _AA观察到的模式，这些物种沿纬度梯度利用了不同的碳源，包括大量的细菌重做材料和微藻，主要是颗粒状有机物混合物。种类型和采样位置中δ既起到角色¹³ Ç _AA变异性，这提示局部产生和分解过程的影响。玛卡玛钙和马鞭草有证据表明它们利用了不同质量的有机物，这表明它们可能会在季节性基础上将其饮食偏好转变为更多的有害物，但是这也受到地理位置的影响。这些观察结果可能对底栖生物产生重要影响，因为随着气候变暖以及食物网结构的变化，有机材料的微生物再加工将增加。