Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system
Abstract Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and decline worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (Salmo trutta L.) is an ideal model species for stu...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2019-05-01
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| Series: | Ecology and Evolution |
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| Online Access: | https://doi.org/10.1002/ece3.5191 |
| _version_ | 1818940593578967040 |
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| author | Cornelya F. C. Klütsch Simo N. Maduna Natalia Polikarpova Kristin Forfang Paul Eric Aspholm Tommi Nyman Hans Geir Eiken Per‐Arne Amundsen Snorre B. Hagen |
| author_facet | Cornelya F. C. Klütsch Simo N. Maduna Natalia Polikarpova Kristin Forfang Paul Eric Aspholm Tommi Nyman Hans Geir Eiken Per‐Arne Amundsen Snorre B. Hagen |
| author_sort | Cornelya F. C. Klütsch |
| collection | DOAJ |
| description | Abstract Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and decline worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (Salmo trutta L.) is an ideal model species for studying anthropogenic influences on genetic integrity, as it has experienced significant genetic alterations throughout its natural distribution range due to habitat fragmentation, overexploitation, translocations, and stocking. The Pasvik River is a subarctic riverine system shared between Norway, Russia, and Finland, subdivided by seven hydroelectric power dams that destroyed about 70% of natural spawning and nursing areas. Stocking is applied in certain river parts to support the natural brown trout population. Adjacent river segments with different management strategies (stocked vs. not stocked) facilitated the simultaneous assessment of genetic impacts of dams and stocking based on analyses of 16 short tandem repeat loci. Dams were expected to increase genetic differentiation between and reduce genetic diversity within river sections. Contrastingly, stocking was predicted to promote genetic homogenization and diversity, but also potentially lead to loss of private alleles and to genetic erosion. Our results showed comparatively low heterozygosity and clear genetic differentiation between adjacent sections in nonstocked river parts, indicating that dams prevent migration and contribute to genetic isolation and loss of genetic diversity. Furthermore, genetic differentiation was low and heterozygosity relatively high across stocked sections. However, in stocked river sections, we found signatures of recent bottlenecks and reductions in private alleles, indicating that only a subset of individuals contributes to reproduction, potentially leading to divergence away from the natural genetic state. Taken together, these results indicate that stocking counteracts the negative fragmentation effects of dams, but also that stocking practices should be planned carefully in order to ensure long‐term preservation of natural genetic diversity and integrity in brown trout and other species in regulated river systems. |
| first_indexed | 2024-12-20T06:42:07Z |
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| id | doaj.art-c6e5eb77a2804e2691076aa8bf9e8e22 |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-12-20T06:42:07Z |
| publishDate | 2019-05-01 |
| publisher | Wiley |
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| series | Ecology and Evolution |
| spelling | doaj.art-c6e5eb77a2804e2691076aa8bf9e8e222022-12-21T19:49:50ZengWileyEcology and Evolution2045-77582019-05-019106068608110.1002/ece3.5191Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine systemCornelya F. C. Klütsch0Simo N. Maduna1Natalia Polikarpova2Kristin Forfang3Paul Eric Aspholm4Tommi Nyman5Hans Geir Eiken6Per‐Arne Amundsen7Snorre B. Hagen8Norwegian Institute of Bioeconomy Research (NIBIO) Svanvik NorwayNorwegian Institute of Bioeconomy Research (NIBIO) Svanvik NorwayPasvik Strict Nature Reserve Rajakoski, Murmansk RussiaNorwegian Institute of Bioeconomy Research (NIBIO) Svanvik NorwayNorwegian Institute of Bioeconomy Research (NIBIO) Svanvik NorwayNorwegian Institute of Bioeconomy Research (NIBIO) Svanvik NorwayNorwegian Institute of Bioeconomy Research (NIBIO) Svanvik NorwayDepartment of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics UiT The Arctic University of Norway Tromsø NorwayNorwegian Institute of Bioeconomy Research (NIBIO) Svanvik NorwayAbstract Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and decline worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (Salmo trutta L.) is an ideal model species for studying anthropogenic influences on genetic integrity, as it has experienced significant genetic alterations throughout its natural distribution range due to habitat fragmentation, overexploitation, translocations, and stocking. The Pasvik River is a subarctic riverine system shared between Norway, Russia, and Finland, subdivided by seven hydroelectric power dams that destroyed about 70% of natural spawning and nursing areas. Stocking is applied in certain river parts to support the natural brown trout population. Adjacent river segments with different management strategies (stocked vs. not stocked) facilitated the simultaneous assessment of genetic impacts of dams and stocking based on analyses of 16 short tandem repeat loci. Dams were expected to increase genetic differentiation between and reduce genetic diversity within river sections. Contrastingly, stocking was predicted to promote genetic homogenization and diversity, but also potentially lead to loss of private alleles and to genetic erosion. Our results showed comparatively low heterozygosity and clear genetic differentiation between adjacent sections in nonstocked river parts, indicating that dams prevent migration and contribute to genetic isolation and loss of genetic diversity. Furthermore, genetic differentiation was low and heterozygosity relatively high across stocked sections. However, in stocked river sections, we found signatures of recent bottlenecks and reductions in private alleles, indicating that only a subset of individuals contributes to reproduction, potentially leading to divergence away from the natural genetic state. Taken together, these results indicate that stocking counteracts the negative fragmentation effects of dams, but also that stocking practices should be planned carefully in order to ensure long‐term preservation of natural genetic diversity and integrity in brown trout and other species in regulated river systems.https://doi.org/10.1002/ece3.5191fish stockinggenetic diversitygenetic erosiongenetic integrityhabitat fragmentationSalmo trutta |
| spellingShingle | Cornelya F. C. Klütsch Simo N. Maduna Natalia Polikarpova Kristin Forfang Paul Eric Aspholm Tommi Nyman Hans Geir Eiken Per‐Arne Amundsen Snorre B. Hagen Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system Ecology and Evolution fish stocking genetic diversity genetic erosion genetic integrity habitat fragmentation Salmo trutta |
| title | Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system |
| title_full | Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system |
| title_fullStr | Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system |
| title_full_unstemmed | Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system |
| title_short | Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system |
| title_sort | genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system |
| topic | fish stocking genetic diversity genetic erosion genetic integrity habitat fragmentation Salmo trutta |
| url | https://doi.org/10.1002/ece3.5191 |
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