Collaborative Research: Demographic structure and recruitment patterns of the scyphozoan, Chrysaora melanaster, in the Bering Sea: the influence of climate on ecosystem function

在白令海东部，水母生物量在1990年后急剧增加，并于2000年达到顶峰。在2007-2012年的凉爽时期，生物量再次增加。 总体而言，中等到寒冷的条件往往有利于该系统中的水母。 在人口增加期间，水母可能对白令海食物网产生重大影响，包括狭鳕渔业，因为水母直接以鱼类的年轻生命阶段为食，并与鱼类竞争食物。 该项目将估计白令海主要水母 Chrysaora melanaster 的年龄结构和年龄特定丰度，并将其与成年水母丰度联系起来，以了解其种群结构如何随时间变化。最终目标是估计这种水母的繁殖能力和成功率与气候变化的关系，并调查考​​虑到未来气候情景，这种水母的数量增加是否会成为白令海的重复模式。该项目将通过支持研究生培训，为 STEM 劳动力发展做出贡献。 调查人员将参加 K-12 教师培训研讨会。 本科生将通过现有的本科生研究经验项目参与研究。 小学生将通过参观首席研究员的实验室来了解海洋科学。 将开发一个包含新颖图像的项目网站。 图像处理的开源代码将发布在万维网上，作为更大科学界的资源。在渔业科学和试图了解种群时间变化的其他学科中，在评估与环境变化相关的物种种群动态时纳入特定年龄丰度和年龄结构的重要性已得到充分证实。 我们将进行严格的调查来估计 C. melanaster 的丰度和精细空间分布，包括其早期浮游阶段和成虫阶段，以确定其年龄结构，并构建种群模型来确定招募成功和招募时间。 这项研究将研究胶状浮游动物种群如何应对大规模环境变化，并将有助于了解白令海水母种群再次增加的情况。声纳成像技术 (ARIS1800) 可有效对同系物 C. quinqueciratha 的成虫进行采样，先进的光学浮游动物可视化 (ZOOVIS) 系统可有效对小型水母进行采样。净抽样和新的老龄化技术的结合将提供关于队列内年龄结构的急需信息，并将有助于理解招聘过程，例如单个队列与多个队列。这反过来将能够预测水母丰度及其对白令海生态系统的捕食影响。

In the eastern Bering Sea, jellyfish biomass increased dramatically after 1990 and peaked in 2000. Biomass increased again during the cool period of 2007-2012. Overall, moderate to cold conditions tend to favor jellyfish in this system. During times of population increase, jellyfish likely have major impacts on the Bering Sea food web, including Walleye Pollock fisheries, because the medusae directly feed on young life stages of fish and compete with fish for food. This project will estimate the age structure and age-specific abundances of the predominant jellyfish in the Bering Sea, Chrysaora melanaster, and will relate this to adult medusa abundance in order to understand how their population structure changes with time. The ultimate goal is to estimate the reproductive capacity and success of this jellyfish in relation to climate variability and to investigate the potential for increases of this jellyfish to become a recurring pattern in the Bering Sea given future climate scenarios.This project will contribute to STEM workforce development through the support for the training of a graduate student. The investigators will participate in K-12 teacher training workshops. Undergraduate students will be entrained into the research through an existing Research Experience for Undergraduates program. Elementary school students will be introduced to marine science through visits to the principal investigator?s laboratory. A website for the project, including novel imagery, will be developed. Open-source code for image processing will be posted on the World Wide Web as a resource for the larger scientific community.The importance of incorporating age-specific abundances and age structure in assessments of the population dynamics of a species in relation to environmental change is well-established in fisheries science and other disciplines that attempt to understand the temporal variation of populations. Rigorous investigations will be conducted to estimate the abundance and fine-scale spatial distribution of C. melanaster including both their early planktonic and adult stages, to determine their age structure, and to construct a population model to identify recruit success and recruitment timing. This research will examine how gelatinous zooplankton populations respond to large scale environmental changes and will also facilitate understanding of the reoccurring jellyfish population increases in the Bering Sea. The sonar imaging technologies (ARIS1800) are effective in sampling adult forms of the congener C. quinquecirrha and an advanced optical ZOOplankton VISualization (ZOOVIS) system can sample small jellyfish effectively. The combination of net sampling and new aging techniques will provide much needed information on the age-structure within cohorts and will facilitate understanding of recruitment processes, e.g. single cohort versus multiple cohorts. This will in turn enable forecasting of jellyfish abundance and their predatory impacts in the Bering Sea ecosystem.