Conservation Genetics

, Volume 19, Issue 5, pp 1123–1136 | Cite as

Population genetic structure after 125 years of stocking in sea trout (Salmo trutta L.)

  • Christoph PetereitEmail author
  • Dorte Bekkevold
  • Sascha Nickel
  • Jan Dierking
  • Harry Hantke
  • Albrecht Hahn
  • Thorsten Reusch
  • Oscar Puebla
Research Article


Stocking can be an effective management and conservation tool, but it also carries the danger of eroding natural population structure, introducing non-native strains and reducing genetic diversity. Sea trout, the anadromous form of the brown trout (Salmo trutta), is a highly targeted species that is often managed by stocking. Here, we assess the present-day population genetic structure of sea trout in a backdrop of 125 years of stocking in Northern Germany. The study area is characterized by short distances between the Baltic and North Sea river watersheds, historic use of fish from both watersheds for stocking, and the creation of a potential migration corridor between the Baltic and North Sea with the opening of the Kiel Canal 120 years ago. A survey of 24 river systems with 180 SNPs indicates that moderate but highly significant population genetic structure has persisted both within and between the Baltic and North Sea. This genetic structure is characterized by (i) heterogeneous patterns of admixture between the Baltic and North Sea that do not correlate with distance from the Kiel Canal and are therefore likely due to historic stocking practises, (ii) genetic isolation by distance in the Baltic Sea at a spatial scale of < 200 km that is consistent with the homing behaviour of sea trout, and (iii) at least one genetically distinct Baltic Sea river system. In light of these results, we recommend keeping fish of North Sea and Baltic Sea origin separate for stocking, and restricting Baltic Sea translocations to neighbouring river systems.


Sea trout Population genetics SNPs Stocking Baltic Sea Kiel Canal 



CP was funded by the Federal-Fishing Fund “Fischereiabgabe” of Schleswig-Holstein, the European Fisheries Fund (EFF) and GEOMAR through the Ministry of Energy, Agriculture, the Environment and Rural Areas of Schleswig-Holstein in the frame of the projects “Sea Trout Literature Study, ParrQuant, VariParr & SMARRT (30/SH305E)”. We thank all people involved in the electrofishing campaigns conducted for tissue sampling, especially Tim Kuchenbecker, Jens Wein, Sebastian Albrecht, Enno Prigge and the staff of the Fish Hatchery Altmühlendorf. We also acknowledge the respective local Water and Soil Organizations for permissions and access to their rivers and the Angling Clubs for their help during field samplings.

Supplementary material

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10592_2018_1083_MOESM4_ESM.xlsx (14 kb)
Supplementary material 4 (XLSX 14 KB)


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Copyright information

© Springer Nature B.V. 2018

Authors and Affiliations

  1. 1.GEOMAR Helmholtz Centre for Ocean Research Kiel, Evolutionary Ecology of Marine FishesKielGermany
  2. 2.DTU-Aqua National Institute of Aquatic ResourcesTechnical University of DenmarkSilkeborgDenmark
  3. 3.NLWKN – Lower Saxony Water Management, Coastal Defence and Nature Conservation AgencyLüneburgGermany
  4. 4.Institute of FisheriesMecklenburg-Vorpommern State Research Center for Agriculture and FisheriesRostockGermany
  5. 5.Fish Hatchery Altmühlendorf, Inland and Pond Fisheries Association Schleswig-HolsteinRendsburgGermany
  6. 6.Faculty of Mathematics and Natural SciencesUniversity of KielKielGermany

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