THRESHOLDS: Disentangling the effects of climate-driven processes on North Sea herring recruitment through physiological thresholds

对自下而上（气候驱动，物理驱动）过程如何影响动物的最深刻，机械的理解可以通过探索生命率（生存，生长，繁殖）对多个关键驱动因素的均值和方差变化的反应的生理基础来获得。气候驱动的鱼类变化似乎是由一些影响早期生命阶段生存的（可能相互作用的）过程驱动的。解开这些过程需要实验室、现场和模拟实验的结合。该项目（THRESHOLDS）使用三种独立但综合的方法，以提供一个步骤的变化，我们的机械理解如何气候变化影响海洋系统的结构和功能的低营养水平（重点是鱼类浮游生物和各种大小类的浮游动物）。《门槛》考察了北海大西洋鲱鱼（Clupea harengus）生命的前两个月，这是一年类建立的时期。首先，实验室实验将探讨猎物的类型和大小对幼虫的生理对比热环境下的影响，并校准营养条件代理适用于现场捕获的幼虫。第二，现场采样将首先记录在现场浮游生物（原，微型和中型浮游动物）和鲱鱼幼虫在秋季和冬季在北海的动态。这个浮游生物数据集将与以前的数据一起扩展，以创建北海鲱鱼幼虫及其猎物（15-2000 µm）的独特7年时间序列。最后，控制幼虫生长的时间序列内的关键因素将被确定使用广义加性混合模型和模拟与生理个体为基础的模型。THRESHOLDS使用整体方法推进最先进的技术，以解决i）气候驱动的对关键生态系统参与者招募的影响，ii）未充分研究的原生动物浮游鱼类联系，iii）海洋鱼类幼体的最佳觅食，以及iv）现场捕获的鱼类幼体的生理代理的校准和使用。此外，北海鲱鱼幼虫是研究气候驱动的浮游生物动态的理想案例研究，因为i）已经收集了任何海洋鱼类早期生命阶段的最长，空间明确的时间序列之一，ii）成功的前期工作已经开发了生理技术并收集了将用于本研究的现场样本，iii）存在具有良好记录的基于生理的IBM，和iv）存在一个非常强大的国际合作者网络，他们将提供船载时间和历史样本的实物捐助，并沿着项目PI，提供目标物种生态学的无与伦比的知识基础。

The most profound, mechanistic understanding of how bottom-up (climate-driven, physical-driven) processes impact animals can be gained by exploring the physiological basis of responses in vital rates (survival, growth, reproduction) to changes in the mean and variance of multiple, key drivers. Climate-driven changes in fish appear driven by a number of (potentially interacting) processes affecting the survival of early life stages. Disentangling these processes requires an amalgam of laboratory, field and modelling experiments. This project (THRESHOLDS) uses three separate but integrated approaches to provide a step change in our mechanistic understanding of how climate variability impacts on the structure and function of lower trophic levels of marine systems (focusing on ichthyoplankton and various size-classes of zooplankton). THRESHOLDS examines the first two months of life of Atlantic herring (Clupea harengus) in the North Sea, the period when the year class is established. First, laboratory experiments will explore the impact of prey type and size on larval physiology under contrasting thermal environments, and calibrate nutritional condition proxies to be applied to field-caught larvae. Second, field sampling will first document the in situ plankton (proto-, micro-, and mesozooplankton) and larval herring dynamics during the fall- and wintertime in the North Sea. This plankton dataset will be extended with previous data to create a unique 7 yr-time series of North Sea herring larvae and its prey (15-2000 µm). And finally, key factors controlling larval growth within the time series will be identified using Generalized Additive Mixed Models and simulations with an physiological Individual-based model. THRESHOLDS advances the state-of-the-art using a holistic approach to address i) climate-driven impacts on recruitment of a key ecosystem player, ii) the under-studied protozooplankton-ichthyoplankton link, iii) optimal foraging in marine fish larvae, and iv) the calibration and use of physiological proxies on field-caught fish larvae. Furthermore, North Sea herring larvae are an ideal case study to examine climate-driven plankton dynamics because i) one of the longest, spatially-explicit time series of early life stages of any marine fish has been collected, ii) successful pre-work has developed the physiological techniques and collected field samples to be used in this study, iii) a physiological-based IBM with a proven track record exists, and iv) a very strong network of international collaborators exists who will offer in-kind contributions of ship-time, historical samples and, along with the project PI, provide an unsurpassed knowledge base of the ecology of the target species.