Effective protection of migratory fish requires long‐term conservation encompassing active restoration and management measures with follow‐up studies. The main findings of long‐term (1995–2019) monitoring of anadromous and potamodromous brown trout Salmo trutta in the River Bidasoa are presented. The main aims were evaluating trout number and median migration date changes, and assessing the effects of management (closures, size limits and quotas, fish stoking) and connectivity measures (fishways and weir removals). Results showed an increasing trend in upstream migrants and decrease in migration dates (earlier migrations). Effects of overlapping measures were difficult to differentiate and were affected by environmental conditions. Statistical analysis demonstrated that fishing closures (2008–2011) and fishway construction (2008) were of great importance, whereas the effect of fish stocking (2003–2012) was variable and unclear. The unexpectedly short‐term effect of three weir removals (2014–2016) may have been due to unusually high discharges in March, affecting the recruitment during previous years.

中文翻译：

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恢复措施对大西洋河流的影响：比达索阿河海鳟和河鳟褐鳟种群25年概览

要有效保护迁徙鱼类，就需要长期保护，包括采取积极的恢复和管理措施以及后续研究。监测的溯河和淡水洄游鱼类鳟长期（1995年至2019年）的主要结果褐鳟在河Bidasoa被介绍。主要目的是评估鳟鱼数量和中位数迁徙日期变化，并评估管理（封闭，规模限制和定额、,鱼）和连通性措施（鱼道和堰的清除）的影响。结果表明，上游移民呈上升趋势，而迁徙日期减少（较早迁徙）。重叠措施的效果难以区分，并且受环境条件的影响。统计分析表明，关闭捕鱼（2008-2011年）和鱼道建设（2008年）非常重要，而鱼类种群（2003-2012年）的影响却是多变的且不清楚。三处堰的拆除（2014-2016年）的短期影响出乎意料，可能是由于三月份异常高的排水量，影响了前几年的招聘。