ABSTRACT: The maraena whitefish Coregonus maraena is a threatened anadromous species in the North Sea, which in the past was decimated to near extinction. Since the late 1980s, several re-establishment programs have been implemented in rivers draining into the North Sea, but the scientific basis for sustainable conservation measures is often lacking, since little is known about the biology of this species. In this study, otolith microchemistry of fish ranging from 24.6 to 58.4 cm in total length (median 31.3 cm, SD 8.4 cm) was used to characterize the migration behavior of a reintroduced population of maraena whitefish from the River Elbe, Germany. Our analyses revealed the presence of 3 different migration patterns: (1) one-time migration into high-salinity habitat (North Sea) within the first year of life (29.6%), (2) multiple migrations between low- and high-salinity habitats starting in the first year of life (14.8%) and (3) permanent residency within low-salinity habitats, a pattern displayed by the majority (55.6%) of sampled individuals. Not only do these results reveal differential migration behavior, but they also indicate that permanent river residency is common in the River Elbe population of C. maraena. The role of the Elbe as both a feeding and a spawning habitat should thus be considered more explicitly in current conservation measures to support recovery of this species.

中文翻译：

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从德国易北河迁移的斑马白鲑Coregonus maraena种群的部分迁徙

摘要：马拉纳白鲑Coregonus maraena是北海的一种濒危濒危物种，过去曾被濒临灭绝。自1980年代后期以来，已经在流入北海的河流中实施了一些重建计划，但是由于缺乏对该物种的生物学知之甚少，因此经常缺乏可持续保护措施的科学依据。在这项研究中，鱼的耳石微化学总长度在24.6至58.4 cm之间（中位数31.3 cm，SD 8.4 cm）被用来表征从德国易北河重新引入的马拉纳白鲑种群的迁移行为。我们的分析揭示了3种不同的迁移模式：（1）在生命的第一年内一次迁移到高盐度栖息地（北海）（29.6％），（2）低盐度和高盐度生境之间的多次迁移始于生命的第一年（14.8％），以及（3）低盐度生境中的永久居留权，这是大多数抽样个体（55.6％）表现出的一种模式。这些结果不仅揭示了不同的迁徙行为，而且还表明，在易北河人口中，永久性河流居住很普遍。C. maraena。因此，在当前的保护措施中应更明确地考虑易北河既是觅食地又是产卵地的作用，以支持该物种的恢复。