Retrospective Determination of Atlantic Croacker Migration Through Laser-Based Elemental Analysis of Otoliths

每年的变化，在鱼的数量生存， 第一年的生活（称为招聘或年级实力）是 往往足以控制渔业的成败 几年后 尽管有科学和经济效益 这将导致如果一年级的实力可以估计之前， 鱼达到了适销对路的规模，招聘预测已经证明 是一个难以实现的目标。 可能造成年度差异的机制 大西洋黄花鱼的年级强度包括 产卵的地点和时间， 河口苗圃区的平流，持续时间和相对湿度 在河口时的生长速率，以及迁移的年龄和日期 在河口的生活结合年龄结构 基于耳石日生长的生长和存活测量 环，该项目将测试这些假设使用一种新的激光- 基于元素分析技术（LS-ICPMS）， 确定孵化地点，估计年龄和日期 在个别鱼类中的后续迁移。 该技术是基于 鱼耳石（耳石）的非细胞性质， 通过每天同心增加的矿化组织， 一个中央核 考虑到元素组成 一个给定的日环的元素组成反映了 在同一天通过鱼鳃的水， 水团之间的迁移在一定的年龄和/或日期将是 记录为耳石元素组成的变化， 适当的每日增量。 由此推论， 孵化时间和地点的差异将反映在 耳石核的元素组成差异。 目前，海洋鱼类的标记很少（如果有的话 更不用说过去的运动和水体的指标 协会 该项目的成功完成， 不仅对大西洋的招聘预测有影响， 黄鱼，但对于研究的补充，股票结构，迁移 以及世界各地的渔业管理。

Year to year variations in the number of fish which survive the first year of life (termed recruitment or year class 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 year class 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 year class 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 of the estuary as an adult. In conjunction with age-structured measures of growth and survival based on otolith daily growth rings, this project will test these hypotheses using a new laser- based elemental analysis technique (LS-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 acellular 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 water which passed through the fish's gills on that same day, migration between water masses at some age and/or date will be recorded as a change in 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. At present there are few (if any) markers of marine fish populations, let alone indicators of past movement and water mass association. Successful completion of this project has implications not only for recruitment predication of Atlantic croaker, but for studies of recruitment, stock structure, migration and fisheries management around the world.