RAPID: Recolonization dynamics following mass mortality in the ecologically important sunflower star (Pycnopodia helianthoides)

许多海洋物种以其庞大的种群规模和高扩散潜力而闻名，这是因为它们的幼体后代在定居到成体栖息地之前在公海度过的时间。尽管向日葵海星(Pycnopodia Helianthoides)具有这些特征，但由于疾病爆发和气候变暖，其数量在2013年至2020年期间大幅下降，导致世界自然保护联盟将其列为极度濒危物种。向日葵星有助于维持海带森林生态系统的生态平衡；它在大片范围内的缺失导致了人们对生态系统未来的担忧。这一损失突出表明，在全球变化压力正在加剧的时候，需要更好地了解这种具有生态重要性的物种的扩散和恢复动态。甲虫的广泛丧失，加上最近在其消失的范围内发现的新幼虫，创造了一个机会来回答关于新殖民者之间的遗传联系、殖民者的来源种群、基因表达模式、与环境因素的联系以及它们对该物种未来的影响等问题。调查人员正在与一个已经对海岸进行调查的不同合作伙伴团队合作，从新的殖民者那里收集基因信息。这里提出的研究通过与自然保护协会的持续合作，对海藻的保护行动产生了直接和相应的影响，并填补了旨在将这一海带森林生态系统的重要成员恢复到其历史范围的未来保护决策的一个重要空白。随着越来越多的物种受到迅速加剧的全球变化的威胁，了解恢复动态是推动保护行动的重要和必要的步骤。这位研究人员正在为附近的一所社区大学开发一门教学课程，并将对一名本科生进行培训。近年来，与人类压力相关的大规模人口统计下降有所增加，这引发了人们对物种恢复能力的质疑。自2013年以来，由于海星损耗(SSW)疾病和气候变暖，具有重要生态意义的向日葵海星(Pycnopodia Helianthoides)遭受了急剧下降(88%-100%)。甲虫的广泛丧失提供了一个背景，最近在灭绝范围内发现的新幼虫提供了一个机会来研究四个过程--(1)扫射繁殖成功，(2)凝聚扩散，(3)幼虫克隆，和(4)等位基因冲浪--对大规模死亡后种群的进化轨迹的贡献。此外，识别繁殖体的来源种群，评估基因表达谱，并分析殖民者的基因-环境关联，有助于阐明有利于恢复或发出持续威胁信号的潜在殖民路径。研究人员正在从许多合作伙伴那里征集新的机会主义的毕氏杆菌标本，并对加利福尼亚州和俄勒冈州的任何观察做出回应，以获取样本并生成测试分离上述过程的假设所需的整个基因组重新测序数据。随着越来越多的物种受到迅速加剧的全球变化的威胁，了解恢复动态对于了解海洋底栖环境中的种群动态至关重要。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。

Many marine species are known for their large population sizes and high dispersal potential due to the time their larval offspring spend in the open ocean before settling into the adult habitat. Despite these characteristics, that often buffer against decimation, the sunflower sea star (Pycnopodia helianthoides) suffered major declines between 2013 and 2020 due to a disease outbreak and warming events, which led to listing by the IUCN as Critically Endangered. The sunflower star helps maintain ecological balance in kelp forest ecosystems; its absence across large swaths of its range has led to concerns for the future of the ecosystem. This loss has highlighted the need to better understand dispersal and recovery dynamics in this ecologically important species in a time when global change stressors are intensifying. The widespread loss of Pycnopodia — combined with recent sightings of new juveniles in the range where it’s been lost — created an opportunity to answer questions about the genetic relatedness among new colonists, source populations of colonists, patterns of gene expression, and associations with environmental factors, and their implications for the future of the species. The investigators are collaborating with a diverse team of partners already surveying the coast, to collect genetic information from new colonists. The research proposed here has direct and consequential impacts on conservation actions for Pycnopodia through ongoing collaborations with the Nature Conservancy and fills an important gap for future conservation decisions aimed at restoring this important member of the kelp forest ecosystem to its historical range. As more species come under threat from rapidly intensifying global change, understanding recovery dynamics is an important and necessary step in instigating conservation actions. The investigator is developing a teaching lesson for a nearby community college and an undergraduate student will be trained.Massive demographic declines associated with anthropogenically-induced stressors have increased in recent years, raising questions about species’ ability to recover. The ecologically important sunflower sea star (Pycnopodia helianthoides) has suffered a precipitous (88–100%) decline since 2013 due to sea star wasting (SSW) disease and warming. The widespread loss of Pycnopodia provides a backdrop against which recent sightings of new juveniles in the extirpated range offer an opportunity to examine the contributions of four processes — (1) sweepstakes reproductive success, (2) cohesive dispersal, (3) larval cloning, and (4) allele surfing — to the evolutionary trajectory of populations following mass mortality. Additionally, identifying propagules’ source populations, evaluating gene expression profiles, and analyzing genotype–environment associations of colonists can help elucidate potential colonization pathways that favor recovery or signal ongoing threats. The investigators are soliciting new opportunistic collections of Pycnopodia from many partners and are responding to any observation in California and Oregon to acquire the samples and generate the whole genome resequencing data needed to test hypotheses segregating the aforementioned processes. As more species come under threat from rapidly intensifying global change, understanding recovery dynamics is critical to understanding population dynamics in the marine benthic environment.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.