Anadromous chars are iteroparous and have complex migratory patterns, with multiple annual descents and ascents between seawater and freshwater. Winter habitat use, whether in the sea or rivers, varies among regions and individuals, and it is necessary to understand these patterns to examine the environmental responses of anadromous chars. We investigated the winter migratory patterns of sea-wintering anadromous white-spotted char in southwestern Hokkaido, Japan, using three different methods: (1) bio-logging for continuous fish behavior record, (2) fish-count observations in the field, and (3) a questionnaire survey for recreational anglers catch. Experimental fish were tagged with micro bio-logger and released in the sea. They showed seasonal behavioral changes, and multiple habitat shifts were estimated: ascending in February, descending in April, ascending in June, and descending in October. Fish counts in the sea and rivers showed that fish were frequently observed in the sea, and occasionally in the river on the same day. The questionnaire survey results indicated that anglers universally caught individuals during all the winter months. Continuous long-term behavioral observations across seasons suggest a new migratory pattern of white-spotted char ascending upstream in February, and combining these results suggests alternative migratory patterns between the sea and the river in winter.

溯河螈是反复繁殖的，具有复杂的迁徙模式，每年在海水和淡水之间进行多次下降和上升。冬季栖息地的使用，无论是在海洋还是河流中，因地区和个体而异，有必要了解这些模式以检查溯河炭的环境响应。我们使用三种不同的方法调查了日本北海道西南部越冬溯河白斑炭的冬季洄游模式：（1）连续鱼类行为记录的生物记录，（2）野外鱼类计数观察，以及(3)休闲垂钓者捕捞问卷调查。实验鱼用微型生物记录器标记并在海中释放。他们表现出季节性的行为变化，并估计了多个栖息地变化：二月上升，四月下降，六月上升，十月下降。海洋和河流中的鱼类数量表明，鱼在海中经常被观察到，并且在同一天偶尔在河流中。问卷调查结果表明，垂钓者在整个冬季都普遍捕获个体。跨季节持续的长期行为观察表明，白斑炭在二月份向上游上升的新洄游模式，结合这些结果表明，冬季海洋和河流之间存在不同的洄游模式。问卷调查结果表明，垂钓者在整个冬季都普遍捕获个体。跨季节持续的长期行为观察表明，白斑炭在二月份向上游上升的新洄游模式，结合这些结果表明，冬季海洋和河流之间存在不同的洄游模式。问卷调查结果表明，垂钓者在整个冬季都普遍捕获个体。跨季节持续的长期行为观察表明，白斑炭在二月份向上游上升的新洄游模式，结合这些结果表明，冬季海洋和河流之间存在不同的洄游模式。