1. Animal movements are influenced by the environment they inhabit and the need to maximise fitness and minimise cost. As such, seasonal thermal cycles in temperate lakes play an important role in the selection of habitat by species. Lake trout (Salvelinus namaycush) is a native top predator in the Laurentian Great Lakes and currently under rehabilitation in Lake Ontario. This cold, deep‐water species is known to migrate to shallower depths in the autumn to spawn, but their spatial and seasonal distribution have not been examined in detail.
2. We quantified the residency and home ranges of 24 lake trout in eastern Lake Ontario across a full year (1 May 2017 to 30 April 2018) using acoustic telemetry to assess the influence of seasonal thermal cycles. Specifically, we used three thermal logging stations in the eastern basin, 164 acoustic receivers, and a total of over 1,000,000 detections to describe seasonal distribution. We also documented occurrences of long‐distance movements (via 130 acoustic receivers located in the western basin of Lake Ontario), and thus the potential spatial overlap of populations from the eastern and western basins.
3. During stratification (1 July–1 November), lake trout (n = 24) showed a horizontally restricted distribution in regions of deeper water in eastern Lake Ontario. A variable and broad distribution was observed around the shallower Kingston Basin shoals during isothermal (1 January–30 April), spring warming (1 May–30 June; spring mix), and autumn cooling (2 November–31 December) periods. Home range sizes ranged from 0.1 to 3,966 km² among all thermal cycles, with the largest observed during cooling autumn mix conditions driven by four individuals. Large variation in home range area was observed among individuals, and, thus, means were not statistically different between seasons. Three individuals occupied shallower shoals even during stratified conditions, and another individual crossed the entire lake from the east to the west end of Lake Ontario, travelling over 200 linear km in 17 days.
4. Our results confirm that thermal regimes and spawning needs affect the spatial use of lake trout in Lake Ontario, but demonstrate that there are broad distributions during isothermal conditions, highly individualistic spatial utilisation, and inter‐individual variation in spatial distribution and exploratory behaviour. All of these behaviours are consistent with other top predator species.
5. Defining the spatial utilisation and distribution of individuals are important steps toward a better understanding of reintroduced species ecology in freshwater ecosystems. The variation of individual lake trout distribution across seasons implies that individuals may have different influences on the overall ecosystem function and potentially different responses to increasing water temperatures. These results suggest that an adaptive management approach is required when rehabilitating populations of this native fish where populating multiple habitats in an ecosystem is an objective in the face of a changing environment.

中文翻译：

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大型湖泊中季节性季节性热循环中湖鳟（Salvelinus namaycush）的空间分布

1. 动物的运动受到它们所居住的环境以及最大化适应度和最小化成本的需求的影响。因此，温带湖泊的季节性热循环在按物种选择栖息地方面起着重要作用。鳟鱼（Salvelinus namaycush）是Laurentian大湖中的原生顶级捕食者，目前在安大略湖中正在恢复之中。已知这种冷的深水物种在秋天会迁移到较浅的深度以产卵，但尚未详细检查它们的空间和季节分布。
2. 我们使用声学遥测技术评估了安大略湖东部一整年（2017年5月1日至2018年4月30日）内24个湖鳟的居住地和栖息地范围，以评估季节性热循环的影响。具体而言，我们使用了东部盆地的三个热测站，164个声波接收器以及总共超过1,000,000次的探测来描述季节分布。我们还记录了长距离运动的发生（通过位于安大略湖西部盆地的130个声波接收器），从而记录了东部和西部盆地人口的潜在空间重叠。
3. 在分层过程中（7月1日至11月1日），鳟鱼（n  = 24）在安大略湖东部的较深水域显示出水平受限的分布。在等温（1月1日至4月30日），春季增暖（5月1日至6月30日；春季混合）和秋季降温（11月2日至12月31日）期间，金斯敦盆地浅滩周围观察到了变化广泛的分布。范围为0.1至3,966 km ^2的范围在所有热循环中，由四个人驱动的秋季降温混合条件下观察到的最大。个体之间的家园面积差异很大，因此，季节之间的均值在统计学上没有差异。即使在分层条件下，三个人仍占据浅滩，另一个人从安大略湖的东到西越过整个湖面，在17天内移动了200多个线性公里。
4. 我们的结果证实了热力状态和产卵需求会影响安大略湖中鳟鱼的空间利用，但表明在等温条件下，高个体化的空间利用以及空间分布和探索行为的个体差异之间存在广泛的分布。所有这些行为都与其他顶级捕食者物种一致。
5. 定义个体的空间利用和分布是更好地了解淡水生态系统中重新引入的物种生态的重要步骤。个体鳟鱼在整个季节中的分布变化意味着个体可能会对整体生态系统功能产生不同的影响，并且可能对水温升高做出不同的反应。这些结果表明，在恢复这种本地鱼类种群的过程中，需要适应性管理方法，而面对不断变化的环境，在一个生态系统中居住多个栖息地是一个目标。