Collaborative Research on carbon cycling in the circum-Arctic flaw lead-polynya system: A radionuclide and molecular ecological approach

该提案将通过对相同的样本采用独特的分析组合，提高对冰穴目前碳循环的认识，冰穴是北极铅缺陷系统的主要特征：采用放射性核素方法测量碳通量、来源和衰减，采用分子和酶方法评价微生物多样性和水解活性。先前在两个主要冰穴（不受河流影响）的研究表明，来自透光层的有机物通量很高，但在“朦胧层”中强烈衰减。“单独的微生物研究表明，下沉的颗粒被大量的活性细菌定殖，在零度以下的沃茨中的水解活性与在温暖的海洋中一样高。关于与北极（或其他海洋）沃茨的微亮区颗粒有关的特定细菌的信息很少，几乎没有关于微生物多样性如何与海洋内部的碳通量或海洋和陆地碳的不同输入有关的信息。在连续几年的同一季节，对北极系统的几个主要冰穴（两条河流影响，一条没有）进行比较研究，将有助于对北冰洋季节性无冰可能导致的碳循环的可能变化形成更广泛的观点。拟议的研究计划将通过现代分子（或任何）技术来表征在减少碳通量方面发挥作用的微生物群落。这种综合方法的成功可能对评估世界海洋其他地方的碳循环方面很有价值。两位主要研究人员都是敬业的教育工作者，也是研究人员。除了为研究生和本科生提供独特的跨学科培训外，他们还将参与创新的船上计划，作为多国合作企业（NABOS）和加拿大ArcticNet“船上学校”计划的一部分，该计划致力于通过让高中生直接参与研究来吸引土著社区参与研究。

This proposal will improve understanding of present carbon cycling in polynyas, major features of the flaw lead system in the Arctic, by applying a unique combination of analyses to the same samples: radionuclide approaches for measuring carbon fluxes, sources and attenuation and molecular and enzymatic approaches for evaluating microbial diversity and hydrolytic activity. Previous work in two major polynyas (not influenced by rivers) showed that the flux of organic matter from the photic zone is high, yet strongly attenuated in the "twilight zone." Separate microbial work showed that sinking particles are colonized by an abundance of active bacteria, with hydrolytic activities as high in subzero waters as in warmer seas. Little information exists on specific bacteria associated with particles in the twilight zone of Arctic (or other marine) waters, with virtually none on how microbial diversity may relate to carbon flux in the ocean's interior or to differing inputs of marine and terrestrial carbon. This comparative research in several of the major polynyas of the Arctic system (two river-influenced, one not), in the same season over successive years, will help to develop a broader perspective on the possible changes in carbon cycling likely to result from a seasonally ice-free Arctic Ocean. The proposed research plan will characterize by modern molecular (or any) techniques the microbial communities that play a role in attenuating carbon flux. The success of this combined approach may prove valuable to evaluating aspects of carbon cycling elsewhere in the world oceans. Both principal investigators are dedicated educators, as well as researchers. In addition to providing graduate and undergraduate students with unique cross-disciplinary training, they will also be engaged in innovative shipboard programs, as part of a multi-national cooperative venture (NABOS), and the Canadian ArcticNet "Schools on Board" program dedicated to engaging indigenous communities in research by bringing in high school students to participate directly in research.