Schoen Alexandra N, Hutton Melody, Klein Andrew, Versluis Riley, Kroeker Derek, Hasler Caleb T
Department of Biology, The University of Winnipeg, Winnipeg, Manitoba, Canada.
Department of Natural Resources and Indigenous Futures, Province of Manitoba, Lac du Bonnet, Manitoba, Canada.
J Exp Zool A Ecol Integr Physiol. 2025 Nov;343(9):981-994. doi: 10.1002/jez.70013. Epub 2025 Jul 16.
Catch-and-release angling (C&R) is a conservation strategy that assumes released fish survive and contribute to populations. However, C&R stress, particularly during spawning, may impact reproductive females and their offspring, such as changes in maternal offspring investment. Here, we studied the effects of maternal stress on lake trout (Salvelinus namaycush), a heavily targeted C&R species, and their offspring. Females were angled, blood sampled, and either held for 48 h (Bag), or held for 48 h and air-exposed every 12 h to mimic repeated C&R events (Air+Bag). A third group of fish (Control) was not held and sampled immediately after capture only (Control). Females in bagged treatments were again blood sampled after 48 h to determine stress indices (cortisol, glucose, and lactate). Following treatment, fish were euthanised and eggs were collected and incubated for 69 days post-fertilization (DPF). Eggs and larvae were temporally analyzed for cortisol, macromolecular contents (glycogen, protein, water, and lipids), and morphometrics (wet mass, dry mass, and length). Maternal cortisol levels increased in bagged treatments, showing deviation in the stress response. Similarly, in these treatments, egg cortisol was elevated at 3 and 12 DPF, and in larvae at 69 DPF. While there were limited changes in macromolecular contents between treatments, the Air+Bag treatment demonstrated increases in egg and larval mass, as well as longer larvae at 69 DPF. These findings suggest maternal stress impacts the stress axis and morphometric development in lake trout offspring. However, the long-term implications of altered larval stress response and growth on lake trout populations remain unclear and a critical area of future work to develop sustainable recreational fisheries.
钓放式钓鱼（C&R）是一种保护策略，该策略假定被放生的鱼类能够存活并对种群数量有所贡献。然而，钓放应激，尤其是在产卵期间，可能会影响处于繁殖期的雌鱼及其后代，比如母代对子代的投资变化。在此，我们研究了母代应激对湖鳟（Salvelinus namaycush，一种被大量钓放的鱼类）及其后代的影响。将雌鱼钓获、采集血液样本，然后一部分雌鱼被放置48小时（袋装组），或者放置48小时且每隔12小时进行空气暴露以模拟反复的钓放事件（气曝+袋装组）。第三组鱼（对照组）仅在捕获后不做放置并立即采样（对照组）。袋装处理组的雌鱼在48小时后再次采集血液样本以确定应激指标（皮质醇、葡萄糖和乳酸）。处理后，对鱼实施安乐死并收集鱼卵，受精后孵化69天（DPF）。对鱼卵和幼体进行定时分析，检测皮质醇、大分子物质含量（糖原、蛋白质、水分和脂质）以及形态指标（湿重、干重和体长）。袋装处理组中母代皮质醇水平升高，表明应激反应出现偏差。同样，在这些处理组中，鱼卵皮质醇在3 DPF和12 DPF时升高，幼体皮质醇在69 DPF时升高。虽然各处理组之间大分子物质含量变化有限，但气曝+袋装处理组的鱼卵和幼体质量增加，且在69 DPF时幼体体长更长。这些发现表明母代应激会影响湖鳟后代的应激轴和形态发育。然而，幼体应激反应和生长变化对湖鳟种群的长期影响仍不明确，这是未来发展可持续休闲渔业工作的一个关键领域。
