Historic catches, abundance, and decline of Atlantic salmon Salmo salar in the River Elbe
Historic catches, abundance, and decline of Atlantic salmon Salmo salar in the River Elbe
复制标题
易北河大西洋鲑鱼 Salmo salar 的历史捕获量、丰度和减少
作者：
C. Wolter
自16世纪中叶以来，易北河流域的渔业统计数据已被汇编和分析，以评估1。大马哈鱼洄游的空间分布与格局；总丰度的鲑鱼存量，以及3。鲑鱼数量减少对当地的影响、原因和时间滞后。编制了从1552年至1949年期间67个地点长达117年的捕捞数据和渔业统计。虽然通常不完整，但现有数据揭示了鲑鱼捕获量的年际空间格局。特别是，在遥远的支流或源头，最近的或异常的鲑鱼记录可以用洪水事件来解释。在易北河，历史上每年大约收获4000条鲑鱼，远高于最近估计的300-400条鲑鱼。易北河流域鲑鱼数量减少的时空格局有力地说明了上游河段历史产卵地对鲑鱼恢复的重要性，以及大河对人类干扰的复原力。这两项发现都强调了在鲑鱼恢复中需要一种集水区方法，包括与上游集水区源头的结合和纵向连接。
Fisheries statistics available from the River Elbe catchment since the middle of the 16th century onwards have been compiled and analyzed to assess 1. the spatial distribution and patterns of returning salmon, 2. the total abundance of the salmon stock, as well as 3. local impacts, reasons, and time lags of salmon decline. Catch data and fisheries statistics of up to 117 years from 67 sites have been compiled covering a period from 1552 to 1949. Although often incomplete, the available data revealed strong inter-annual spatial patterns of salmon catches. In particular, last or exceptional salmon records in distant tributaries or headwaters were significantly explained by flood events. In the River Elbe, the historical salmon harvest amounts of about 4,000 salmon annually are well above recent estimates of 300–400 returning salmon. The spatio-temporal patterns of salmon decline in the River Elbe catchment strongly indicate the importance of the historical spawning sites in the upstream river sections for salmon recovery as well as the resilience of large rivers against human disturbances. Both findings underline the need for a catchment approach in salmon rehabilitation including incorporation of and longitudinal connectivity to the upper catchment headwaters.