Catch-and-release ice angling is a popular recreational activity, but little is known about the postrelease behavior of fish in the winter. Cold water temperatures and an ambush hunting strategy may constrain Northern Pike Esox lucius, limiting their postrelease movements to a small area near the capture location. We used manual acoustic telemetry to track 15 Northern Pike ranging from 56 to 98.5 cm total length for up to 7 d after catch-and-release ice angling in Buffalo Pound Lake, Saskatchewan, Canada. All of the fish but one moved unexpectedly long distances of several km over the tracking period. For the fish that were tracked over all 7 d, path lengths traveled ranged from 1.4 to 18.4 km. The minimum daily distance traveled ranged from 0 to 4.6 km and varied significantly by tracking day; the fish moved shorter distances on day 4 postrelease. There was a significant interaction between fish size and day postrelease; larger fish moved shorter minimum daily distances and dispersed shorter distances from the release site over the first 2 d of tracking. In contrast, by 5 d after release, both the largest and smallest fish had dispersed the longest distances from the release site and intermediate-sized fish dispersed the least. The cumulative path length traveled by day 5 of tracking did not reveal any significant size-based patterns. Our study raises the possibility that relatively large movements may be common for Northern Pike in the winter despite cold water temperatures and their expected foraging behavior. In addition, postrelease behavior varies with fish size. Habitat and space requirements for Northern Pike in the winter can encompass much larger areas and more habitat features than has been previously envisioned.

中文翻译：

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在冰下追逐北梭鱼：抓放冰钓后的长距离运动

抓放冰钓是一种流行的娱乐活动，但人们对冬季放生后的鱼类行为知之甚少。冷水温度和伏击狩猎策略可能会限制北派克鱼 Esox lucius，将他们的发布后移动限制在捕获位置附近的一个小区域内。在加拿大萨斯喀彻温省布法罗庞德湖捕捞放冰后，我们使用手动声学遥测技术跟踪了 15 条总长度从 56 到 98.5 厘米不等的北梭鱼长达 7 天。在跟踪期间，除了一条鱼之外，所有的鱼都意外地移动了几公里的长距离。对于在所有 7 d 内被跟踪的鱼，路径长度从 1.4 到 18.4 公里不等。每日最小行驶距离为 0 至 4.6 公里，并随追踪日变化显着；这条鱼在发布后第 4 天移动的距离较短。鱼的大小和放生后天数之间存在显着的相互作用；在追踪的前 2 天，较大的鱼移动的最小每日距离更短，并且离释放地点的距离更短。相比之下，到释放后 5 d，最大和最小的鱼都离释放点的距离最长，中型鱼的距离最小。跟踪第 5 天的累积路径长度没有显示任何基于大小的显着模式。我们的研究提出了一种可能性，即尽管冷水温度和预期的觅食行为，北梭鱼在冬季可能会发生相对较大的运动。此外，释放后的行为因鱼的大小而异。北派克冬季对栖息地和空间的要求可以包含比以前预想的更大的区域和更多的栖息地特征。跟踪第 5 天的累积路径长度没有显示任何基于大小的显着模式。我们的研究提出了一种可能性，即尽管冷水温度和预期的觅食行为，北梭鱼在冬季可能会发生相对较大的运动。此外，释放后的行为因鱼的大小而异。北派克冬季对栖息地和空间的要求可以包含比以前预想的更大的区域和更多的栖息地特征。跟踪第 5 天的累积路径长度没有显示任何基于大小的显着模式。我们的研究提出了一种可能性，即尽管冷水温度和预期的觅食行为，北梭鱼在冬季可能会发生相对较大的运动。此外，释放后的行为因鱼的大小而异。北派克冬季对栖息地和空间的要求可以包含比以前设想的更大的区域和更多的栖息地特征。