Collaborative Research: Pattern and process in the abundance and recruitment of Caribbean octocorals

珊瑚礁受到各种自然和人为干扰，生态系统退化的后果已广为人知。然而，报告的变化偏向于鱼类和石珊瑚，就加勒比珊瑚礁而言，这种偏向最明显的例子是珊瑚礁（"软珊瑚"）。虽然它们数量丰富，在许多加勒比珊瑚礁中占主导地位，但由于难以确定它们和量化其丰度，它们很少被纳入研究。 在一些地方，有令人信服的证据表明，软珊瑚的数量已经增加，即使石珊瑚已经变得不那么常见。 这表明软珊瑚比石珊瑚更能适应影响珊瑚的各种干扰。研究这些变化的最佳珊瑚礁是那些已经研究了几十年的珊瑚礁，可以为最近的事件提供十年的背景，在这方面，美属维尔京群岛圣约翰的珊瑚礁是独一无二的。自1987年以来一直在研究珊瑚礁上的石珊瑚，自2014年起研究软珊瑚。 这提供了无与伦比的平台，以评估珊瑚丰度和招聘模式;确定这些珊瑚礁上发生的变化模式，并确定负责珊瑚种群恢复力的过程。该项目将把对软珊瑚的监测从4年延长到8年，并将在此框架内审查幼珊瑚的作用及其对海底粗糙度、海水流动和海藻的反应，以确定软珊瑚的成功。这项工作还将评估飓风伊尔玛和玛丽亚的破坏性影响是否改变了变化模式。为配合这些努力，该项目将与当地高中密切结合，调查人员将在当地高中主办海洋生物学俱乐部，并为学生和教师提供独立学习的机会。独特的培训机会将提供给本科生和研究生，以及博士后研究员，所有这些人都将学习和工作在圣约翰，研究人员将培训珊瑚礁研究人员通过双手识别软珊瑚的种类-在佛罗里达群岛举行的研讨会上。了解环境条件的变化如何影响主要生物群落的群落结构是生态学的定义21世纪的目标 将在美属维尔京群岛圣约翰的维尔京群岛国家公园内的浅礁上研究这些条件对珊瑚礁的整体影响，该公园是该区域进行时间最长的珊瑚礁群落动态长期研究的地点之一。在NSF-LTREB的支持下，研究人员自1987年以来一直在研究该地区石珊瑚群落的长期变化，并在2014年利用NSF-OCE的支持建立了一个石珊瑚“覆盖”这一十年的观点。本项目从这段独特的历史延伸，这段历史被飓风伊尔玛和玛丽亚的影响所打断，将珊瑚群落生态学置于十年的背景下，调查人员利用一套丰富的遗留数据来更好地了解加勒比珊瑚礁的现在和不久的将来。这个为期四年的项目将在两个并行的方面取得进展：第一，将珊瑚群落的时间序列分析从四年延长到八年，以表征群落结构变化的模式和速度，第二，进行一项假设驱动的实验计划，重点是珊瑚定居，这将揭示珊瑚比石珊瑚更有效地在当今珊瑚礁上定居的机制。 具体而言，研究人员将进行测定和操纵实验，解决四个假设，重点是以下角色：（1）生境复杂性在区分珊瑚和石珊瑚补充生态位中的作用，（2）补充生态位在调节定居后成功中的作用，（3）藻坪和大型藻类中的竞争在决定珊瑚和石珊瑚补充成功中的作用，以及（4）珊瑚冠层在调节颗粒物和幼体向海底的通量中的作用。这项研究的结果将被整合，以评估推动珊瑚虫与硬珊瑚虫在当今加勒比珊瑚礁上具有更高生态复原力的因素。这一奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Coral reefs are exposed to a diversity of natural and anthropogenic disturbances, and the consequences for ecosystem degradation have been widely publicized. However, the reported changes have been biased towards fishes and stony corals, and for Caribbean reefs, the most notable example of this bias are octocorals ("soft corals"). Although they are abundant and dominate many Caribbean reefs, they are rarely included in studies due to the difficulty of both identifying them and in quantifying their abundances. In some places there is compelling evidence that soft corals have increased in abundance, even while stony corals have become less common. This suggests that soft corals are more resilient than stony corals to the wide diversity of disturbances that have been impacting coral corals. The best coral reefs on which to study these changes are those that have been studied for decades and can provide a decadal context to more recent events, and in this regard the reefs of St. John, US Virgin Islands are unique. Stony corals on the reefs have been studied since 1987, and the soft corals from 2014. This provides unrivalled platform to evaluate patterns of octocoral abundance and recruitment; identify the patterns of change that are occurring on these reefs, and identify the processes responsible for the resilience of octocoral populations. The project will extend soft coral monitoring from 4 years to 8 years, and within this framework will examine the roles of baby corals, and their response to seafloor roughness, seawater flow, and seaweed, in determining the success of soft corals. The work will also assess whether the destructive effects of Hurricanes Irma and Maria have modified the pattern of change. In concert with these efforts the project will be closely integrated with local high schools at which the investigators will host marine biology clubs and provide independent study opportunities for their students and teachers. Unique training opportunities will be provided to undergraduate and graduate students, as well as a postdoctoral researcher, all of whom will study and work in St. John, and the investigators will train coral reef researchers to identify the species of soft corals through a hands-on workshop to be conducted in the Florida Keys.Understanding how changing environmental conditions will affect the community structure of major biomes is the ecological objective defining the 21st century. The holistic effects of these conditions on coral reefs will be studied on shallow reefs within the Virgin Islands National Park in St. John, US Virgin Islands, which is the site of one of the longest-running, long-term studies of coral reef community dynamics in the region. With NSF-LTREB support, the investigators have been studying long-term changes in stony coral communities in this location since 1987, and in 2014 NSF-OCE support was used to build an octocoral "overlay" to this decadal perspective. The present project extends from this unique history, which has been punctuated by the effects of Hurricanes Irma and Maria, to place octocoral synecology in a decadal context, and the investigators exploit a rich suite of legacy data to better understand the present and immediate future of Caribbean coral reefs. This four-year project will advance on two concurrent fronts: first, to extend time-series analyses of octocoral communities from four to eight years to characterize the pattern and pace of change in community structure, and second, to conduct a program of hypothesis-driven experiments focused on octocoral settlement that will uncover the mechanisms allowing octocorals to more effectively colonize substrata than scleractinian corals on present day reefs. Specifically, the investigators will conduct mensurative and manipulative experiments addressing four hypotheses focusing on the roles of: (1) habitat complexity in distinguishing between octocoral and scleractinian recruitment niches, (2) the recruitment niche in mediating post-settlement success, (3) competition in algal turf and macroalgae in determining the success of octocoral and scleractian recruits, and (4) role of octocoral canopies in modulating the flux of particles and larvae to the seafloor beneath. The results of this study will be integrated to evaluate the factors driving higher ecological resilience of octocorals versus scleractinians on present-day Caribbean reefs.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.