Collaborative Research: The Role of Sponges in the Coastal Nitrogen Cycle

海绵通过非凡的抽水率和快速、动态的生物地球化学转化相结合，极大地改变了生态系统的水质。海绵群落在海洋环境中无处不在，可以栖息在热带生态系统中40%以上的底栖区域。在本项目中，来自北卡罗来纳州查佩尔山大学、夏威夷大学马诺阿分校和华盛顿大学的一个研究小组将通过量化海绵氮（N）在佛罗里达湾N循环中的作用，继续他们正在进行的关于海绵氮（N）转化和通量在沿海环境中的重要性的调查。特别是这些占主导地位的底栖生物在满足整个海湾的初级生产者的N需求的重要性。 该团队先前的研究表明，海绵溶解无机氮（DIN）通量到佛罗里达群岛海螺礁的上覆沃茨比任何其他底栖氮（N）来源都要大。 在选择佛罗里达湾作为他们的研究区域，该小组将受益于丰富的可用数据有关的N源和再循环，包括新的N输入的估计值，和定量海绵底栖生物量。通过进行原位海绵N通量测量，他们希望能够有助于一个潜在的重要的回收氮源，以前没有被量化的N预算的信息。本研究的总体目标是通过量化溶解和颗粒有机氮转化为DIN和N2的速率和机制，确定海绵介导的N循环过程在佛罗里达湾的重要性，该湾海绵丰富，其生物量已在数百个站点进行了量化，并且其在水过滤中的关键作用已经确立（氮气）的关键海绵物种，并阐明控制N2生产的自然因素，如海绵组织溶解氧浓度。更广泛的影响：海绵在沿海环境的营养平衡中发挥着至关重要的作用，因为它们在热带，温带和极地栖息地中数量丰富，它们处理大量的水，许多常见物种拥有丰富和活跃的微生物种群。然而，它们对大多数环境中的地球化学循环的影响在很大程度上仍然是未知的。在这项研究中，研究生和本科生以及博士后研究员将在实验室和现场环境中学习一系列最先进的技术和仪器，当结果最终合成出版时，他们将受益于与来自不同领域的研究人员交流思想。

Sponges dramatically alter ecosystem water quality through the combination of extraordinary pumping rates and rapid, dynamic biogeochemical transformations. Sponge communities are ubiquitous in marine environments and can inhabit over 40% of the benthic area in tropical ecosystems. In this project, a research team from the University of North Carolina at Chapel Hill, the University of Hawaii at Manoa, and the University of Washington will continue their ongoing investigations of the importance of sponge nitrogen (N) transformations and fluxes in coastal environments through quantifying their role in the N cycle of Florida Bay, specifically the importance of these dominant benthic organisms in meeting the N demands of primary producers throughout the Bay. The team's previous research demonstrated that sponge dissolved inorganic nitrogen (DIN) flux to overlying waters at Conch Reef, Florida Keys, was larger than any other benthic nitrogen (N) source. In choosing Florida Bay as their study area, the team will benefit from the wealth of available data concerning N sources and recycling, including estimated values for new N inputs, and quantitative sponge benthic biomass. By performing in situ sponge N flux measurements they expect be able to contribute information about a potentially important recycled N source that has not previously been quantified in N budgets. The overarching goal of this research is to establish the importance of sponge-mediated N cycling processes in Florida Bay where sponges are abundant, their biomass has been quantified at hundreds of stations and their key role in water filtration has been established, by quantifying rates and mechanisms of transformations of both dissolved and particulate organic nitrogen to DIN and N2 (nitrogen gas) by key sponge species, and elucidating controls on N2 production by natural factors such as sponge tissue dissolved oxygen concentrations. Broader Impacts: Sponges play a crucial role in the nutrient balance of coastal environments because they are abundant in tropical, temperate and polar habitats, they process tremendous volumes of water, and many common species host abundant and active microbial populations. Their impact on biogeochemical cycling in most environments, however, remains largely unknown. During this study, graduate and undergraduate students and a postdoctoral fellow will learn in both laboratory and field settings a spectrum of state-of-the-art techniques and instrumentation firsthand and, when the results are ultimately synthesized for publication, they will benefit from participation in the exchange of ideas with established researchers from diverse fields.