Collaborative Research: A Multidisciplinary Study of Selective Tidal-Stream Transport: Bio-physical Coupling and Behavioral Mechanisms

许多无脊椎动物和鱼类利用选择性潮汐流输送（STST）进行水平运动。STST基于垂直迁移模式，动物在潮汐的一个阶段离开底部进入水柱，在另一个阶段停留在底部或接近底部。物种内的STST的一个显著但未被研究的方面是在不同生活史阶段迁移方向的逆转。蓝蟹（Callinectes sapidus）在产卵后的STST方向逆转是本多学科研究的重点。在产卵迁徙期间，雌鱼利用退潮运输从河口向大海移动。在释放幼虫后，它们会逆转方向，经过涨潮运输重新进入河口。本研究的具体目标是：利用生物遥测技术观察和表征产卵迁徙过程中的运动模式和身体状况；模拟观测到的物理条件和迁移路径，并利用耦合生物物理模型在时间和空间上推断这些结果；确定STST背后的行为是由活动中的内源性节律介导的，还是由对外源性线索的行为反应介导的；并确定影响成熟卵雌鱼退潮运输和产卵后雌鱼涨潮运输的因素。该研究整合了生物和物理海洋学领域，将扩大我们对STST的线索、行为和物理机制的理解，STST是许多海洋和河口物种共同的生活史特征，对种群的延续至关重要。具体地说，将实地观察和实验室实验的结果与循环模型相结合，将使研究人员能够预测促进或阻碍雌性蓝蟹往返产卵地点的水文和气象条件，并估计河口不同区域释放的幼虫对沿海水域发育幼虫供应的相对贡献。

Many invertebrates and fishes use selective tidal-stream transport (STST) for horizontal movement. STST is based on a vertical migration pattern, in which animals leave the bottom and enter the water column during one phase of the tide and remain on or near the bottom during the other phase. One remarkable but unstudied aspect of STST within a species is the reversal in the direction of migration at different life history stages. Migration of the blue crab Callinectes sapidus, involving a reversal in STST direction following spawning, is the focus of this multidisciplinary research. During spawning migration, ovigerous females use ebb-tide transport to move seaward from estuaries. After releasing larvae, they reverse direction and undergo flood -tide transport to re-enter the estuary. The specific goals of this research are to: use biotelemetry to observe and characterize the pattern of movement and physical conditions during the spawning migration; simulate observed physical conditions and migratory pathways and extrapolate these results in time and space using a coupled bio-physical model; determine whether the behavior underlying STST is mediated by an endogenous rhythm in activity or by behavioral responses to exogenous cues; and determine the cues mediating the onset of ebb-tide transport by females with mature eggs and flood-tide transport of post--spawn females. The study integrates the fields of biological and physical oceanography and will expand our understanding of the cues, behaviors, and physical mechanisms underlying STST, a common life history trait among many marine and estuarine species that is essential for continuation of populations. Specifically, combining results from field observations and laboratory experiments with a circulation model will allow researchers to predict hydrologic and meteorologic conditions that promote or impede female blue crab migration to and from spawning sites and estimate the relative contribution of larvae released from different areas of an estuary to the supply of developing larvae in coastal waters.