Planning Visit: U.S.-Danish Research on Diversity and Toxin Production of Pseudo-nitzschia Species in Sub-Arctic and Arctic Regions with Focus on Iron Enriched Regions.

海洋硅藻--伪菱形藻在近海和海洋环境中的分布，以及与硅藻--S潜在的有毒软骨藻酸(DA)的产生有关的生态系统后果，相对来说知之甚少。通过这次研究计划访问，西贝尔·巴尔古和一名来自路易斯安那州立大学和农工学院的研究生将与丹麦合作伙伴哥本哈根大学的尼娜·伦德霍尔姆启动一个合作项目。他们打算研究亚北极和北极地区伪菱形藻物种的多样性和毒素生产，特别是铁富集区。需要对这种来源的生物进行准确的物种鉴定和分子研究，以进一步评估分类群的生态和毒素产生。美国首席研究员S在富铁水域、大陆边缘沿海水域对DA进行生态测量方面的优势与丹麦合作伙伴S在北极和亚北极地区的系统学和分子生物学方面的广泛知识相辅相成。国际研究小组将共同开始工作，通过使用电子显微镜和基因组分析来确认伪菱形藻物种的最终身份。他们的努力预计将开始揭示更多关于在阿拉斯加湾和格陵兰水域等地通过食物链生产和转移DA的信息，其长期目标是记录世界海洋中假菱形藻的分布和毒性。这次研究访问实现了项目目标，即通过使美国和欧洲的专家能够共享研究资源并在共同感兴趣和能力很强的领域计划有益的项目，来增进对这种天才和菌株的相对毒性的基本知识。更广泛的影响包括为路易斯安那州立大学的一名研究生提供早期职业介绍，了解前沿国际合作和实地工作。根据之前的观察，研究小组成员得出结论，铁的富集会选择性地促进产毒素菌株的生长。因此，新的结果可以确定潜在的DA危险，这些危险应该在旨在通过在深海中固存来从大气中消除二氧化碳的铁肥实验中加以考虑。

OISE 0922684BarguRelatively little is know about the distribution of marine diatom, Pseudo-nitzschia, in offshore, oceanic environments and corresponding ecosystem-wide consequences associated with the diatom?s potential production of the toxic Domoic Acid (DA). Though this research planning visit, Sibel Bargu and a graduate student from Louisiana State University and A & M College will initiate a collaborative project with Danish partner, Nina Lundholm at the University of Copenhagen. They intend to study diversity and toxin production of the Pseudo-nitzschia species in sub-Arctic and Arctic regions with a particular focus on iron enriched regions. Accurate species identification and molecular studies of this source organism are needed to further evaluate the ecology and toxin production of the taxa. The U.S. principal investigator?s strengths in ecological measurements of DA in iron rich waters, seaward of continental margins, complement the Danish partner?s extensive knowledge of systematics and molecular biology in Artic and sub-Arctic locations. Together the international team will begin work to confirm the ultimate identity of the Pseudo-nitzschia species by using electron microscopy and genomic analysis. Their efforts are expected to begin to reveal more about the production and transfer of DA through food chains in places like the Gulf of Alaska and Greenlandic waters, with the long-term goal of documenting Pseudo-nitzschia distribution and toxicity in world oceans. This research visit fulfills the program objective of advancing basic knowledge of this genius and the relative toxicity of strains by enabling experts in the United States and Europe to share research resources and plan beneficial projects in areas of strong mutual interest and competence. Broader impacts include providing one Louisiana State University graduate student with an early career introduction to forefront international collaboration and field work. Based on previous observations, team members conclude that iron enrichment may selectively promote growth of the toxin producing strains. Therefore, new results could identify potential DA hazards that should be considered in iron fertilization experiments designed to remove carbon dioxide from the atmosphere through sequestration in deep oceans.