RAPID: The black urchin (Diadema antillarum) massive resurgent die-off: Causes, demographic and community consequences

近几十年来，加勒比珊瑚礁生态系统中的许多海洋物种都受到了疾病的影响。20世纪80年代初发生的一起有充分记录的大规模死亡事件影响了长刺黑海胆Diadema antillarum，因为它对珊瑚礁生态系统产生了广泛的影响。海胆的功能是守门人食草动物，主要以大型藻类为食，防止藻类过度生长珊瑚礁。在20世纪80年代，一种未知的疾病导致加勒比海90%以上的海胆死亡，将珊瑚礁的景观从珊瑚变成了藻类。近40年过去了，黑海胆的数量还没有恢复。2022年初，加勒比海沿岸，包括波多黎各，报告了一起新的平纹夜蛾死亡事件。这一快速项目正在识别与当前死亡事件有关的微生物。研究人员还在对比环境条件和疾病发病率的情况下评估海胆种群。研究结果有助于更好地了解Diadema疾病的原因和后果，学到的见解可能有助于预防或减轻未来的死亡事件。该项目正在为未被充分代表的本科生和研究生提供微生物学、生物信息学、生物化学和生态学方面的培训。通过使用多重组学技术，这个快速项目正在促进我们对加勒比地区目前Diadema的死亡的理解，包括宿主和病原体的相互作用以及这些因素如何受到环境因素的影响。研究人员正在探讨以下问题：(1)患病海胆的微生物和生化特征与健康海胆相似吗？(2)环境因素，即温度、盐度、pH和溶解氧是否影响发病率？(3)不同大小类别的海胆是否受到疾病的不同影响？该项目的重点是波多黎各东部和北部海岸的四个研究地点，这些地点之前已经收集了人口和生化数据。每隔三个月，使用元基因组和非靶向代谢组学策略，对健康和患病的小球藻海胆进行微生物组的变化评估。此外，正在对每个地点8个样点的海胆进行计数和测量，以确定疾病如何调节生活史特征，即种群大小结构和密度，并评估疾病发病率。正在评估疾病发病率与环境测量之间的关系。这些多学科的方法和尖端技术，结合现有的人口和微生物数据，使这项研究成为一个独一无二的项目，在代谢、微生物、种群和生态系统水平上研究疾病的进展和影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In recent decades, many marine species in Caribbean coral reef ecosystems have been impacted by disease. A well-documented mass mortality event affecting the long-spined black sea urchin Diadema antillarum in the early 1980s stands out because it had wide-ranging impacts on reef ecosystems. The urchins function as gatekeeper grazers, feeding mainly on macroalgae and preventing algae from overgrowing reefs. In the 1980s, an unknown disease killed over 90% of these urchins across the Caribbean, changing the reefscape from coral to algal dominated. Nearly 40 years later, black sea urchin populations have yet to recover. In early 2022, a new mortality event of D. antillarum was reported along the Caribbean, including Puerto Rico. This RAPID project is identifying the microbes involved in the current mortality event. The investigators are also assessing urchin populations under contrasting environmental conditions and disease incidences. Results are providing a better understanding of the causes and consequences of disease in Diadema, and insights learned may help prevent or mitigate future mortality events. The project is providing training for underrepresented undergraduate and graduate students in microbiology, bioinformatics, biochemistry, and ecology.With use of multi-omics technology, this RAPID project is advancing our understanding of the current die-off of Diadema in the Caribbean, including host-pathogen interactions and how these are influenced by environmental factors. The investigators are pursuing the following questions: (1) Are the microbial and biochemical profiles of diseased urchins similar to healthy ones? (2) Do environmental factors, i.e., temperature, salinity, pH, and dissolved oxygen, influence disease incidence? (3) Are different size classes of urchins differentially being affected by the disease? This project is focusing on four study sites along the eastern and northern coast of Puerto Rico, where demographic and biochemical data have been previously collected. At three-month intervals, healthy and diseased D. antillarum urchins are being evaluated for changes in the microbiome using metagenomic and untargeted metabolomic strategies. In addition, urchins from eight transects per site are being counted and measured to determine how disease modulates life-history traits, i.e., population size-structure and density, and to assess disease incidence. The relationship between disease incidence and environmental measurements is being assessed. These multidisciplinary approaches and cutting-edge techniques, combined with the existing demographic and microbial data, make this a one-of-a-kind project to study the progression and effects of the disease at the metabolic, microbial, population, and ecosystem levels.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.