Across the world’s oceans, western boundary currents are strengthening and warming faster than the global average. This is expected to have large impacts on the distribution of pelagic fishes, as their dispersal and physiological range limits shift. Monitoring the distribution of larval fish assemblages, sampled with plankton nets, allows for population and community-level responses to climate-driven changes to be observed without reliance on fisheries data. Here, we characterise patterns in the distribution of larval fish over 15° of latitude with highly variable conditions driven by a western boundary current, the East Australian Current, using a newly available larval fish database supplemented with recently collected samples. Using generalized additive mixed models, we show strong non-linear relationships between larval fish taxonomic richness and abundance with latitude. During autumn, winter and spring, both larval fish abundance and richness are greater in equatorward latitudes (28°S) than in more poleward ones (43°S), with this pattern reversed during the summer. The region where the East Australian Current separates from the coast delineates a zone of marked change in larval fish richness and abundance. Analyses of larval fish assemblages using Gaussian copula graphics models revealed a strong association between assemblage composition and temperature. The direction of temperature effects on individual taxa varied greatly, highlighting the complex nature of possible climate-driven shifts. Our study highlights the utility of compiling multi-voyage databases and their role in monitoring the global oceans.

在全球海洋中，西部边界流的增强和变暖速度快于全球平均水平。预计这将对远洋鱼类的分布产生重大影响，因为它们的扩散和生理范围受到限制。监测用浮游生物网取样的幼体鱼群的分布，可以观察到人口和社区一级对气候驱动变化的反应，而无需依靠渔业数据。在这里，我们使用新近获得的幼体鱼数据库，并补充了最近收集的样本，以15个纬度为基础，在受西部边界流，东澳大利亚洋流驱动的高度可变条件下，对幼体鱼的分布模式进行了表征。使用广义加性混合模型，我们显示了幼虫鱼分类学丰富度与纬度丰富度之间的强非线性关系。在秋季，冬季和春季，赤道纬度（28°S）的幼体鱼的丰度和丰度都比极极纬度的纬度（43°S）的大，而夏季则相反。东澳大利亚洋流与海岸分开的区域勾勒出一个区域，其幼鱼的丰富度和丰富度发生了显着变化。使用高斯copula图形模型对幼体鱼的组合进行分析后发现，组合物的组成与温度之间存在很强的联系。温度对单个分类单元的影响方向变化很大，突显了可能由气候驱动的转变的复杂性。我们的研究突出了编译多航次数据库的实用性及其在监测全球海洋中的作用。