Dynamics of the Fraser River plume front: implications for fish larval survival

了解导致鱼类种群波动的因素，包括鲑鱼，仍然是渔业研究中的一个重要挑战。海洋初期的摄食对鱼类的成功招募至关重要。因此，在具有短寿命和非常动态（短暂）锋面特征的沿海地区，海洋幼鱼的存活率可能会提高。这是因为近海岸锋面，包括羽流、潮汐和大陆架断裂锋面，与邻近水域相比，似乎具有更高的生产力和更长的滞留时间。这些锋线的短暂性往往没有反映在浮游生物种群的增加上，这就造成了用传统实地技术检测其生物重要性的困难。生物速率过程，而不是浮游生物种群，似乎在这样的前缘特征中得到了加强。拟议研究的总体目标是更好地了解导致鱼类种群数量和增收波动的潜在因素。具体而言，本研究将调查小规模物理干扰与幼鱼生物学和种群统计学之间的相互作用。这将采用一种新的方法，通过将细胞生物分子的复合稳定同位素组成与目前在生物海洋学领域使用的标准技术相结合来解决。该研究将为小规模海洋过程和浮游热点在整个生态系统预算中的重要性提供基础知识。预计本研究结果可用于将上述知识纳入鱼类种群模型，以改善鱼类种群管理和幼鱼生存。

The understanding of factors leading to fluctuations in fish populations, including salmonids, remains an important challenge in fisheries research. The feeding during the initial oceanic period is crucial for the recruitment success of fish. The juvenile oceanic survival may therefore be enhanced in coastal regions reach with short-living and very dynamic (ephemeral) frontal features. This is because near-coastal fronts, including plume, tidal and shelf-break fronts, appeared to have higher productivity and longer retention time compared to adjacent waters. The ephemeral nature of these fronts is often not reflected in enhanced planktonic stocks, which create difficulties in detection of their biological importance by traditional field techniques. Biological rate processes, rather than plankton stocks, appeared to be enhanced in such frontal features. The overall goal of the proposed research is to better understand the underlying factors contributing to fluctuations in fish populations and recruitment. Specifically, this research will investigate interactions between small-scale physical disturbances and larval fish biology and demography. This will be addressed using a novel methodological approach by combining a compound stable isotope composition of cellular biomolecules with standard techniques currently used in the field of biological oceanography. This research will provide a fundamental knowledge of the significance of small-scale oceanic processes and planktonic hot spots in the overall ecosystem budget. It is anticipated that the findings of this study could be used to improve management of fish stocks and juvenile fish survival by incorporating the above knowledge into fish population modeling.