Retrospective Determination of Atlantic Croaker Migration through Laser-Beamed Elemental Analysis of Otoliths

小行星9416579 在生命的第一年存活下来的鱼的数量（称为补充或一年级强度）的年度变化往往足以控制几年后渔业的成败。 尽管科学和经济效益，这将导致如果一年级强度可以估计之前，鱼达到了可销售的大小，补充预测已被证明是一个难以捉摸的目标。 可能的机制，有助于年到一年的变化，大西洋黄花鱼的强度，包括在产卵的位置和时间，年龄和随后的平流到河口苗圃区，持续时间和相对增长率，而在河口的日期和年龄的变化和迁移出河口作为一个成年人。 结合年龄结构的增长和生存措施的基础上耳石每日生长年轮，这些假设可以使用一种新的激光为基础的元素分析技术（LA-ICPMS），追溯确定孵化地点和估计年龄和日期的个别鱼随后的迁移测试。 该技术基于鱼耳石（耳石）的细胞性质，其通过围绕中央核的矿化组织的同心每日添加而形成。 给定日轮的元素组成反映了耳石在适当的日增量下的元素组成。 由此推论，在孵化的时间和地点的水质差异将反映在耳石核的元素组成差异。 以前的工作证实了LA-ICPMS的分析潜力，并提供了第一个证明，耳石元素组成确实反映了周围水的特性。 当前项目的优势在于这种方法的改进，以及其在现场研究中的应用，使用的样本量远高于任何其他此类研究（1200耳石）。该项目的成功完成不仅对大西洋黄花鱼的补充具有重要意义，而且对世界范围内的补充、种群结构、洄游和渔业管理等方面的研究也具有重要意义。 ***

9416579 Jones Year to year variations in the number of fish which survive the first year of life (termed recruitment or yearclass strength) are often sufficient to control the success or failure of the fishery a few years later. Despite the scientific and economic benefits which would result if yearclass strength could be estimated before fish reached a marketable size, recruitment prediction has proved to be an elusive goal. Likely mechanisms contributing to year-to-year variations in the yearclass strength of Atlantic croaker include variations in the location and timing of spawning, the age and date of subsequent advection to the estuarine nursery area, the duration and relative growth rate while in the estuary, and the age and date of migration out of the estuary as an adult. In conjunction with age-structured measures of growth and survival based on otolith daily growth rings, these hypotheses can be testes using a new laser-based elemental analysis technique (LA-ICPMS) to retroactively determine the hatching site and estimate the age and date of subsequent migrations in individual fish. The technique is based on the a cellular nature of the fish otolith (earstone), which forms through the concentric daily additions of mineralized tissue around a central nucleus. Given the fact that the elemental composition of a given daily ring reflects the elemental composition of the otolith at the appropriate daily increment. By corollary, water mass differences at the time and place of hatching will be reflected in elemental composition differences in the otolith nucleus. Previous work confirmed the analytic potential of LA-ICPMS and provided the first demonstration that otolith elemental composition does indeed reflect characteristics of the ambient water. The strength of the current project lies in the refinement of this approach, and its application in a field study using sample sizes well above that of any other study of this type (1200 otoliths). Su ccessful completion of this project has implications not only for recruitment of Atlantic croaker, but for studies of recruitment, stock structure, migration and fisheries management around the world. ***