Collaborative Research: Terrestrial Linkages to Microbial and Metazoan Communities in Coastal Ecosystems of the Beaufort Sea

北极的沿海生态系统通过河流排放和海岸线侵蚀接收了大量的陆地有机物。这种有机物的命运是当地人关心的问题，因为它关系到沿海海洋的生物生产。它还对全球地球化学循环具有更广泛的意义。目前流行的模式是，陆地有机物输入北冰洋是高度不稳定的。然而，大多数支持这一范式的研究都是在仲夏到夏末进行的。这一努力的前提是，陆地有机物，无论是溶解形式还是颗粒形式，都提供了重要的碳和能源补贴，在一年的大部分时间里支持和维持沿海沃茨的异养活动和食物网。这项工作将集中在阿拉斯加博福特海沿岸的一组沿着12个实地，位于巴特岛和伊努皮亚克村的卡克托维克附近。从泻湖到开放的沿海系统，这些系统接收不同数量的淡水径流，而且与大陆架沃茨的交换特征也有显著差异，将利用这些地点之间的比较来审查生物群落与来自陆地的有机物质输入之间的联系。检查这些联系将有助于确定如何季节性不同的陆地输入的水和有机物的影响微生物和后生动物群落在沿海沃茨的阿拉斯加博福特海。研究人员将通过一个季节性明确的采样计划来解决这个问题，该计划包括在9个月的冰雪覆盖期和夏季进行实地考察。将利用水和沉积物化学、底栖生物和水柱群落特征以及天然丰度同位素示踪剂的测量结果，评价陆地输入在不同水文/水文条件下的重要性。随着北极系统进入气候快速变化的时期，了解北极沿海沃茨陆地碳的命运现在尤为重要。陆地有机物输出的变化可能影响北极沿岸沃茨的总生产量以及自养和异养的相对作用。这种变化对以沿海食物网为生的当地人口以及对陆海耦合感兴趣的广大科学界产生了影响。这项工作的重点是陆地有机物在北极沿海沃茨的命运，必须回答之前，我们可以有效地考虑未来的变化在北极陆海耦合的基本问题。这个合作项目将支持两名研究生和两名博士后的论文研究，并继续一个非常成功的K-12推广计划，题为？北极的气候变化：一个将科学家与K-12学生联系起来的互动计划？其中包括为本地Kaktovik K-12学生建立一个夏季野外科学项目。村委会理事会表示非常愿意让中学生参加可以与Kaktovik学区的教师一起提供的实践科学活动。

Coastal ecosystems of the Arctic receive extraordinarily large quantities of terrestrial organic matter through river discharge and shoreline erosion. The fate of this organic matter is of local interest as it relates to biological production in the coastal ocean. It is also of broader interest with respect to global biogeochemical cycling. The prevailing paradigm is that terrestrial organic matter inputs to the Arctic Ocean are highly recalcitrant. However, most studies supporting this paradigm have been conducted during mid- to late- summer. This effort is based on the premise that terrestrial organic matter, in both dissolved and particulate form, provides an important carbon and energy subsidy that supports and maintains heterotrophic activity and food webs in coastal waters during much of the year. The work will focus on a set of 12 field sites along the Alaskan Beaufort Sea coast, in the vicinity of Barter Island and the Inupiaq village of Kaktovik. Comparisons among sites ranging from lagoons to open coastal systems that receive differing amounts of freshwater runoff and also differ markedly in their exchange characteristics with shelf waters will be used to examine linkages between biological communities and organic matter inputs from land. Examining these linkages will help determine how seasonally distinct terrestrial inputs of water and organic matter influence microbial and metazoan communities in coastal waters of the Alaskan Beaufort Sea. Researchers will address this question thorough a seasonally explicit sampling program that includes field trips during the 9-month ice covered period as well as summer. Measurements of water and sediment chemistry, benthic and water column community characteristics, and natural abundance isotopic tracers will be used to evaluate the importance of terrestrial inputs under different hydrologic/hydrographic conditions. Understanding the fate of terrestrial carbon in arctic coastal waters is especially important now, as the arctic system enters a period of rapid climatic change. Changes in terrestrial organic matter export could influence total production as well as the relative roles of autotrophy and heterotrophy in arctic coastal waters. Such shifts have consequences for local human populations that use coastal food webs for subsistence and for the broad scientific community interested in land-sea coupling. This work focuses on fundamental questions about the fate of terrestrial organic matter in arctic coastal waters that must be answered before we can effectively consider future changes in land-sea coupling in the Arctic. This collaborative project will support the dissertation research of two graduate students and two post-doctoral associates and also continue a very successful K-12 outreach program, entitled ?Climate Change in the Arctic: An Interactive Program Linking Scientists with K-12 Students? that includes the establishment of a summer field science program for native Kaktovik K-12 students. The Village Council has expressed keen enthusiasm to involve middle school students in hands-on science activities that can be provided in conjunction with teachers from the Kaktovik school district.