Abstract

The spatial distribution of fish early life stages can impact recruitment at later stages and affect population size and resilience. Northeast Arctic (NEA) cod spawning occurs along the Norwegian coast. Eggs, larvae, and pelagic juveniles drift near-surface towards the Barents Sea nursery area. In this study, a 35-year long time series of NEA cod larvae data was analysed in combination with factors that potentially may affect the distribution of eggs and larvae. These factors included biological aspects of the spawning stock, and environmental variables, such as water temperature, wind, ocean current, and prey abundance. Our aim was to shed light on how these factors influence larval abundance and distribution and how larval abundance and distribution influenced recruitment at age 3. We found that biomass and mean weight of the spawners were positively associated with larval abundance and that a high liver condition index of the spawners was associated with a north-easterly distribution of the larvae. The environmental variables showed generally weak or no correlations with abundance or distribution of larvae. Lastly, we found significant association between larval abundance and year-class abundance at age 3, while the spatial distribution metrics of the larvae, i.e. distribution extent, mean longitude, and mean latitude, showed no significant association with future year-class abundance.

中文翻译：

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气候和产卵种群结构对东北北极鳕鱼幼体空间分布的影响

摘要

鱼类早期生命阶段的空间分布会影响后期的补充，并影响种群规模和恢复力。北极东北部 (NEA) 鳕鱼产卵发生在挪威海岸。卵、幼虫和远洋幼鱼靠近地表漂向巴伦支海育苗区。在这项研究中，结合可能影响卵和幼虫分布的因素，分析了 35 年长的 NEA 鳕鱼幼虫数据时间序列。这些因素包括产卵种群的生物学方面和环境变量，如水温、风、洋流和猎物丰度。我们的目的是阐明这些因素如何影响幼虫丰度和分布，以及幼虫丰度和分布如何影响 3 岁时的招募。我们发现产卵者的生物量和平均重量与幼虫丰度呈正相关，并且产卵者的高肝脏状况指数与幼虫的东北分布有关。环境变量与幼虫的丰度或分布通常显示出较弱的相关性或没有相关性。最后，我们发现幼虫丰度与 3 岁时的年级丰度之间存在显着关联，而幼虫的空间分布指标，即分布范围、平均经度和平均纬度，与未来的年级丰度没有显着关联。环境变量与幼虫的丰度或分布通常显示出较弱的相关性或没有相关性。最后，我们发现幼虫丰度与 3 岁时的年级丰度之间存在显着关联，而幼虫的空间分布指标，即分布范围、平均经度和平均纬度，与未来的年级丰度没有显着关联。环境变量与幼虫的丰度或分布通常显示出微弱或没有相关性。最后，我们发现幼虫丰度与 3 岁时的年级丰度之间存在显着关联，而幼虫的空间分布指标，即分布范围、平均经度和平均纬度，与未来的年级丰度没有显着关联。