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

北极沿海生态系统通过河流排放和海岸线侵蚀吸收了大量陆生有机物。这些有机物质的命运关系到沿海海洋的生物生产，是当地的利益所在。它在全球生物地球化学循环方面也具有更广泛的意义。普遍的看法是，输入到北冰洋的陆生有机物是高度不稳定的。然而，大多数支持这种范式的研究都是在仲夏到夏末进行的。这一努力是基于这样一个前提，即在一年中的大部分时间里，溶解和颗粒形式的陆地有机物提供了重要的碳和能源补贴，支持和维持了沿海水域的异养活动和食物网。这项工作将集中在阿拉斯加波弗特海岸附近的12个油田，这些油田位于巴特岛和卡克托维克的因努皮克村庄附近。从泻湖到开放的沿海系统等地点之间的比较，这些地点接收不同数量的淡水径流，并且它们与大陆架水域的交换特征也明显不同，将用于检查生物群落与陆地有机物输入之间的联系。检查这些联系将有助于确定季节性不同的陆地水和有机物输入如何影响阿拉斯加波弗特海沿岸水域的微生物和后生动物群落。研究人员将通过一个季节性的明确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。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将用于评估不同水文/水文条件下陆地输入的重要性。随着北极系统进入一个气候快速变化的时期，了解北极沿海水域陆地碳的命运现在尤为重要。陆源有机质输出量的变化会影响北极近岸水域有机质总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和对陆海耦合感兴趣的广大科学界都产生了影响。这项工作的重点是关于北极沿海水域陆生有机物命运的基本问题，在我们能够有效地考虑北极陆海耦合的未来变化之前，必须回答这些问题。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外展项目，名为？北极的气候变化：一个连接科学家和K-12学生的互动项目？其中包括为卡克托维克本地K-12学生建立一个夏季实地科学项目。村委会表达了让中学生参与动手科学活动的强烈热情，这些活动可以与卡克托维克学区的教师一起提供。

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.