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非常大量的陆地有机物质。这种有机物的命运关系到当地的利益，因为它关系到沿海海洋的生物生产。它对全球生物地球化学循环也有更广泛的兴趣。普遍的模式是，输入北冰洋的陆地有机物质是高度顽固的。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，陆地有机物质，无论是溶解的还是颗粒的，都提供了一种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水域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岸沿线的12个现场地点，这些地点位于巴特岛和卡克托维克的因努皮亚克村附近。从泻湖到开阔的沿海系统，从泻湖到开阔的沿海系统，这些地点接收的淡水径流量不同，但与陆架水域的交换特征也明显不同，将利用这些地点之间的比较来检查生物群落和陆地输入的有机物质之间的联系。审查这些联系将有助于确定水和有机物的季节性陆地输入如何影响阿拉斯加波弗特海沿海水域的微生物和后生动物群落。研究人员将通过季节性明确的采样计划来解决这个问题，该计划包括在9个月的冰盖时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自然丰度同位素示踪剂的测量来评估不同水文/水文条件下陆地投入的重要性。现在，随着北极系统进入快速气候变化期，了解北极沿海水域陆地碳的命运尤为重要。陆地有机质输出的变化可能会影响北极沿海水域的总产量以及自养和异养的相对作用。这种转变对使用沿海食物网谋生的当地人口以及对海陆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地有机质命运的基本问题，这些问题必须得到回答，然后我们才能有效地考虑北极海陆耦合的未来变化。这个合作项目将支持两名研究生和两名博士后助理的论文研究，并将继续一个非常成功的K-12外联计划，名为？北极的气候变化：连接科学家和K-12学生的互动计划？这包括为Kaktovik K-12本地学生建立夏季田野科学项目。村委会表达了让中学生参与实践科学活动的强烈热情，这些活动可以与Kaktovik学区的老师一起提供。

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.