COLLABORATIVE RESEARCH: Influence of Temperature and Acidification on the Dynamics of Coral Co-Infection and Resistance

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。珊瑚礁生态系统因最近气温上升和预计海洋酸化加剧而高度濒危。虽然温度已被确定为一些珊瑚疾病暴发的驱动因素，但关于酸化对宿主免疫和病原菌毒力的直接影响，或者与温度的协同作用的可能性，人们尚不清楚。自然珊瑚种群经常受到多种病原体的同时感染，这些病原体也可以影响宿主的免疫反应，但在缺乏经典适应性免疫的无脊椎动物系统中，联合感染的动力学还没有被研究过。气候变化很可能会影响单一感染和混合感染的结果。本项目将研究环境胁迫对海洋扇形珊瑚Gorgonia ventalina与真菌病原菌Sydowii曲霉和原生寄生虫SPx共感染的影响。其目标是确定多重感染、温度和酸化改变宿主抵抗力的机制，从而导致群体内和群体间疾病传播率的变化。该项目的目标是：-确定Sydowii曲霉和SPX曲霉的发病率和混合感染频率。对这两种疾病的详细实地调查将检验混合感染显著的假设，提供关于曲霉病驱动因素的有价值的信息，并将有助于描述一种新出现的海扇疾病的特征。-调查混合感染如何影响海扇的易感性、抵抗力和宿主疾病动态。通过操纵性的实验室接种实验，我们将检验单一感染会增加对第二种病原体的易感性的假设。-研究温度升高和海洋酸化对病原体毒力、潜在宿主抗性以及对单一感染和混合感染的动态的影响。酸化将增加病原体毒力和宿主敏感性的假设将在温度和pH控制的实验系统中进行测试。该系统还将允许探索温度和酸化对宿主免疫和联合感染动力学的潜在协同效应。这项拟议工作的主要学术价值将是更好地理解气候变化如何调节非模式无脊椎动物的联合感染和免疫。虽然真菌病原体主要是机会性的，但迷宫原生动物被认为是贝类的主要病原体。即使在贝类中，关于迷路类的混合感染也知之甚少，而这些原生生物在珊瑚中也完全没有研究过。这项活动的更广泛影响包括对本科生、研究生和博士后研究人员的培训，以及与当地(例如伊萨卡科学中心)和国际教育推广项目(世界银行全球环境基金：全环基金)的合作。此外，公众对珊瑚礁的迷恋可以作为一种工具，引起人们对全球气候危机的关注。研究人员的工作已经从主要的国家和国际媒体收到了相当大的通知，这支持了康奈尔大学的科学传播努力。这种公共利益也使其能够参与将影响全球环境政策的政策讨论，例如在美国珊瑚礁特别工作组面前发言。调查人员通过世界银行的合作努力最近也达到了高潮，出版了《珊瑚疾病手册》和将协调国际珊瑚礁管理的水下身份证。该项目将进一步支持这些努力，以传达继续支持海洋科学、气候研究和主动管理计划的必要性。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."Coral reef ecosystems are highly endangered by recent increases in temperature and by projected increases in ocean acidification. Although temperature has been identified as a driver of some coral disease outbreaks, nothing is known about direct effects of acidification on host immunity and pathogen virulence, or the potential for synergism with temperature. Natural coral populations often suffer from simultaneous infection by multiple pathogens that can also influence host immune responses, but co-infection dynamics have not been investigated in invertebrate systems lacking classical adaptive immunity. Changing climate will very likely influence the outcome of single and co-infection. This project will investigate the influence of environmental stress on co-infection dynamics of the sea fan coral, Gorgonia ventalina, with a fungal pathogen, Aspergillus sydowii and a protist parasite, SPX. The goal is to identify the mechanisms through which multiple infections, temperature and acidification modify host resistance, leading to changes in within- and among-colony rates of disease spread. The Objectives of this project are to: -Identify incidence and co-infection frequency of Aspergillus sydowii and SPX Detailed field surveys of the two diseases will test the hypothesis that co-infection is significant, provide valuable information about drivers of aspergillosis, and will help to characterize an emerging new sea fan disease. -Investigate how co-infection influences sea fan susceptibility, resistance, and within host disease dynamics. Through manipulative lab inoculation experiments we will test the hypothesis that single infections increase susceptibility to a second pathogen. -Examine the effects of temperature increase and ocean acidification on pathogen virulence, on underlying host resistance, and on the dynamics of single and co-infections The hypotheses that acidification will increase pathogen virulence and host susceptibility will be tested in a temperature and pH controlled experimental system. This system will also allow the potential synergistic effects of temperature and acidification on host immunity and co-infection dynamics to be explored. The primary intellectual merit of the proposed work will be a greater understanding of how changing climate mediates co-infection and immunity in a non-model invertebrate. While fungal pathogens are primarily opportunistic, labyrinthulid protozoans are recognized as primary pathogens in shellfish. Even in shellfish, little is known about co-infections involving labyrinthulids, and these protists are entirely unstudied in corals. The Broader impacts of this activity include training of undergraduates, graduate students, and postdoctoral researchers, as well as collaborations with established local (e.g. Ithaca Sciencenter) and international educational outreach programs (World Bank Global Environmental Fund: GEF). In addition, the public's fascination with coral reefs can be used as a tool in drawing attention to the global climate crisis. The considerable notice the investigators work has received from major national and international media has bolstered Cornell's science communication efforts. This public interest has also allowed then to participate in policy discussions that will influence global environmental policies, such as speaking before the U.S. Coral Reef Task Force. The investigators collaborative efforts through the World Bank have also recently culminated in the publication of a Coral Disease Handbook and underwater ID cards that will coordinate international coral reef management. The project will further support these efforts to communicate the need for continued support of the marine sciences, climate studies, and proactive management programs.