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Reed TE, Kane A, McGinnity P, O'Sullivan RJ. Competitive interactions affect introgression and population viability amidst maladaptive hybridization. Evol Appl 2024; 17:e13746. [PMID: 38957310 PMCID: PMC11217556 DOI: 10.1111/eva.13746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 04/03/2024] [Accepted: 06/18/2024] [Indexed: 07/04/2024] Open
Abstract
The deliberate release of captive-bred individuals, the accidental escape of domesticated strains, or the invasion of closely related conspecifics into wild populations can all lead to introgressive hybridization, which poses a challenge for conservation and wildlife management. Rates of introgression and the magnitude of associated demographic impacts vary widely across ecological contexts. However, the reasons for this variation remain poorly understood. One rarely considered phenomenon in this context is soft selection, wherein relative trait values determine success in intraspecific competition for a limiting resource. Here we develop an eco-genetic model explicitly focussed on understanding the influence of such competitive interactions on the eco-evolutionary dynamics of wild populations experiencing an influx of foreign/domesticated individuals. The model is applicable to any taxon that experiences natural or human-mediated inputs of locally maladapted genotypes ('intrusion'), in addition to phenotype-dependent competition for a limiting resource (e.g. breeding sites, feeding territories). The effects of both acute and chronic intrusion depended strongly on the relative competitiveness of intruders versus locals. When intruders were competitively inferior, density-dependent regulation limited their reproductive success (ability to compete for limited spawning sites), which prevented strong introgression or population declines from occurring. In contrast, when intruders were competitively superior, this amplified introgression and led to increased maladaptation of the admixed population. This had negative consequences for population size and population viability. The results were sensitive to the intrusion level, the magnitude of reproductive excess, trait heritability and the extent to which intruders were maladapted relative to locals. Our findings draw attention to under-appreciated interactions between phenotype-dependent competitive interactions and maladaptive hybridization, which may be critical to determining the impact captive breeding programmes and domesticated escapees can have on otherwise self-sustaining wild populations.
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Affiliation(s)
- Thomas Eric Reed
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Adam Kane
- School of Biology and Environmental Science and Earth InstituteUniversity College DublinDublinIreland
| | - Philip McGinnity
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
- Marine Institute, Furnace, Newport, CoMayoIreland
| | - Ronan James O'Sullivan
- Human Diversity Consortium, Faculty of Physiology and Genetics, Department of BiologyUniversity of TurkuTurkuFinland
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2
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Bekkevold D, Besnier F, Frank‐Gopolos T, Nielsen EE, Glover KA. Introgression affects Salmo trutta juvenile life-history traits generations after stocking with non-native strains. Evol Appl 2024; 17:e13725. [PMID: 38962360 PMCID: PMC11219512 DOI: 10.1111/eva.13725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/22/2024] [Accepted: 05/15/2024] [Indexed: 07/05/2024] Open
Abstract
Introgression of non-native conspecifics changes the genetic composition of wild populations, potentially leading to loss of local adaptations and fitness declines. However, long-term data from wild populations are still relatively few. Here, we studied the effects of introgression in a Danish brown trout (Salmo trutta, L.) population, subjected to intensive stocking with domesticated hatchery fish of non-native origin. We used wild-caught genetically wild and admixed trout as well as fish from the partly domesticated hatchery strain used for stocking the river up until ~15 years prior to this study, to produce 22 families varying in hatchery/wild admixture. Following a replicated common-garden experiment conducted in fish tanks from first feeding through 23 weeks at 7, 12, and 16°C, we observed a significant positive relationship between family admixture and fish size upon termination, an effect observed through all levels of admixture. Furthermore, the admixture effect was most distinct at the higher rearing temperatures. Although the hatchery strain used for stocking had been in culture for ~7 generations, it had not been deliberately selected for increased growth. These data thus demonstrate: (i) that growth had increased in the hatchery strain even in the absence of deliberate directional selection for this trait, (ii) that the increasing effect of admixture by temperature could represent inadvertent selection for performance in the hatchery strain at higher temperatures, and most significantly, (iii) that despite undergoing up to five generations of natural selection in the admixed wild population, the genetically increased growth potential was still detectable and thus persistent. Our findings suggest that altered growth patterns and potentially their cascading effects are of importance to the severity of hatchery/wild introgression, especially under changing-climate scenarios and are of general significance to conservation practitioners seeking to evaluate long-term effects of intra-specific hybridization including under recovery.
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Affiliation(s)
- Dorte Bekkevold
- National Institute of Aquatic ResourcesTechnical University of DenmarkSilkeborgDenmark
| | | | - Thomas Frank‐Gopolos
- National Institute of Aquatic ResourcesTechnical University of DenmarkSilkeborgDenmark
| | - Einar E. Nielsen
- National Institute of Aquatic ResourcesTechnical University of DenmarkSilkeborgDenmark
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3
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Power M, Thorstad EB, Forseth T, Fiske P. Temporal shifts in the marine feeding of individual Atlantic salmon inferred from scale isotope ratios. Ecol Evol 2023; 13:e10656. [PMID: 37920771 PMCID: PMC10618632 DOI: 10.1002/ece3.10656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/10/2023] [Accepted: 09/27/2023] [Indexed: 11/04/2023] Open
Abstract
Given the limited information on prey use during the marine residency period for Atlantic salmon, scales were collected from salmon at return to the River Namsen (Norway) for spawning after 1 year at sea, and scale material from the first and second summer marine feeding periods was analysed using stable isotope methods to understand dynamics of their trophic ecology. As the salmon increased in size from the first to second summer, they reduced their feeding niche and specialised more (narrowed the δ13C range) and increased their dependency on higher tropic level (δ15N) prey, likely fish. Changes in δ13C indicated a consistent pattern of movement towards the north and west between summer feeding periods. Hence, salmon during their first year at sea may have a migration route roughly resembling that of previous spawners, as inferred from earlier tagging studies. Feeding conditions and nutrient composition during the last summer at sea, i.e. in the months before returning to the river for spawning, impacted final body size and within-season timing of return. Fish undergoing the largest trophic niche shift (δ13C and δ15N combined) between summer feeding periods, returned earliest. The earliest returning fish had the fastest specific growth rates at sea. Hence, salmon encountering abundant high-quality fish food during the marine migration, particularly during the last months, may reach a size and energetic state whereby it is better to return early to a safer environment in freshwater than risk being eaten by a big predator at sea. Both trophic status (δ15N), resource use (δ13C) and growth rates were significantly correlated between feeding periods. Nutrient composition during the first summer at sea did not impact the fish body length after the following winter, but growth conditions during the first summer evidenced carry-over effects from the first to the second summer of feeding.
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Affiliation(s)
- Michael Power
- Department of BiologyUniversity of WaterlooWaterlooOntarioCanada
| | - Eva B. Thorstad
- Aquatic Ecology DepartmentNorwegian Institute for Nature Research (NINA)TrondheimNorway
| | - Torbjørn Forseth
- Aquatic Ecology DepartmentNorwegian Institute for Nature Research (NINA)TrondheimNorway
| | - Peder Fiske
- Aquatic Ecology DepartmentNorwegian Institute for Nature Research (NINA)TrondheimNorway
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4
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Langille BL, Kess T, Brachmann M, Nugent CM, Messmer A, Duffy SJ, Holborn MK, Van Wyngaarden M, Knutsen TM, Kent M, Boyce D, Gregory RS, Gauthier J, Fairchild EA, Pietrak M, Eddy S, de Leaniz CG, Consuegra S, Whittaker B, Bentzen P, Bradbury IR. Fine-scale environmentally associated spatial structure of lumpfish ( Cyclopterus lumpus) across the Northwest Atlantic. Evol Appl 2023; 16:1619-1636. [PMID: 37752959 PMCID: PMC10519416 DOI: 10.1111/eva.13590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 07/10/2023] [Accepted: 08/14/2023] [Indexed: 09/28/2023] Open
Abstract
Lumpfish, Cyclopterus lumpus, have historically been harvested throughout Atlantic Canada and are increasingly in demand as a solution to controlling sea lice in Atlantic salmon farms-a process which involves both the domestication and the transfer of lumpfish between geographic regions. At present, little is known regarding population structure and diversity of wild lumpfish in Atlantic Canada, limiting attempts to assess the potential impacts of escaped lumpfish individuals from salmon pens on currently at-risk wild populations. Here, we characterize the spatial population structure and genomic-environmental associations of wild populations of lumpfish throughout the Northwest Atlantic using both 70K SNP array data and whole-genome re-sequencing data (WGS). At broad spatial scales, our results reveal a large environmentally associated genetic break between the southern populations (Gulf of Maine and Bay of Fundy) and northern populations (Newfoundland and the Gulf of St. Lawrence), linked to variation in ocean temperature and ice cover. At finer spatial scales, evidence of population structure was also evident in a distinct coastal group in Newfoundland and significant isolation by distance across the northern region. Both evidence of consistent environmental associations and elevated genome-wide variation in F ST values among these three regional groups supports their biological relevance. This study represents the first extensive description of population structure of lumpfish in Atlantic Canada, revealing evidence of broad and fine geographic scale environmentally associated genomic diversity. Our results will facilitate the commercial use of lumpfish as a cleaner fish in Atlantic salmon aquaculture, the identification of lumpfish escapees, and the delineation of conservation units of this at-risk species throughout Atlantic Canada.
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Affiliation(s)
- Barbara L. Langille
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | - Tony Kess
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | - Matthew Brachmann
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | - Cameron M. Nugent
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | - Amber Messmer
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | - Steven J. Duffy
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | - Melissa K. Holborn
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | - Mallory Van Wyngaarden
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | | | - Matthew Kent
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Centre for Integrative GeneticsNorwegian University of Life SciencesÅsNorway
| | - Danny Boyce
- Department of Ocean Sciences, Ocean Sciences CentreMemorial University of NewfoundlandSt John'sNewfoundland and LabradorCanada
| | - Robert S. Gregory
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
| | - Johanne Gauthier
- Maurice Lamontagne Institute, Fisheries and Oceans CanadaQuebecCanada
| | | | - Michael Pietrak
- USDA, Agricultural Research ServiceNational Cold Water Marine Aquaculture CenterFranklinMaineUSA
| | - Stephen Eddy
- University of Maine Center for Cooperative Aquaculture ResearchFranklinMaineUSA
| | | | - Sofia Consuegra
- Centre for Sustainable Aquatic Research, Swansea UniversitySwanseaUK
| | - Ben Whittaker
- Centre for Sustainable Aquatic Research, Swansea UniversitySwanseaUK
| | - Paul Bentzen
- Marine Gene Probe Laboratory, Department of BiologyDalhousie UniversityHalifaxNova ScotiaCanada
| | - Ian R. Bradbury
- Northwest Atlantic Fisheries Centre, Fisheries and Oceans CanadaSt. John'sNewfoundland and LabradorCanada
- Marine Gene Probe Laboratory, Department of BiologyDalhousie UniversityHalifaxNova ScotiaCanada
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5
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Bradbury IR, Lehnert SJ, Kess T, Van Wyngaarden M, Duffy S, Messmer A, Wringe B, Karoliussen S, Dempson JB, Fleming IA, Solberg MF, Glover KA, Bentzen P. Genomic evidence of recent European introgression into North American farmed and wild Atlantic Salmon. Evol Appl 2022; 15:1436-1448. [PMID: 36187183 PMCID: PMC9488674 DOI: 10.1111/eva.13454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 06/10/2022] [Accepted: 07/08/2022] [Indexed: 12/02/2022] Open
Abstract
Gene flow between wild and domestic populations has been repeatedly demonstrated across a diverse range of taxa. Ultimately, the genetic impacts of gene flow from domestic into wild populations depend both on the degree of domestication and the original source of the domesticated population. Atlantic salmon, Salmo salar, used in North American aquaculture are ostensibly of North American origin. However, evidence of European introgression into North American aquaculture salmon has accumulated in recent decades, even though the use of diploid European salmon has never been approved in Canada. The full extent of such introgression as well as the potential impacts on wild salmon in the Northwest Atlantic remains uncertain. Here, we extend previous work comparing North American and European wild salmon (n = 5799) using a 220 K SNP array to quantify levels of recent European introgression into samples of domestic salmon, aquaculture escapees, and wild salmon collected throughout Atlantic Canada. Analysis of North American farmed salmon (n = 403) and escapees (n = 289) displayed significantly elevated levels of European ancestry by comparison with wild individuals (p < 0.001). Of North American farmed salmon sampled between 2011 and 2018, ~17% had more than 10% European ancestry and several individuals exceeded 40% European ancestry. Samples of escaped farmed salmon similarly displayed elevated levels of European ancestry, with two individuals classified as 100% European. Analysis of juvenile salmon collected in rivers proximate to aquaculture locations also revealed evidence of elevated European ancestry and larger admixture tract in comparison to individuals collected at distance from aquaculture. Overall, our results demonstrate that even though diploid European salmon have never been approved for use in Canada, individuals of full and partial European ancestry have been in use over the last decade, and that some of these individuals have escaped and hybridized in the wild.
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Affiliation(s)
- I. R. Bradbury
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, 80 E White Hills Rd St. John’s, Newfoundland, A1C 5X1 Canada
| | - S. J. Lehnert
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, 80 E White Hills Rd St. John’s, Newfoundland, A1C 5X1 Canada
| | - T. Kess
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, 80 E White Hills Rd St. John’s, Newfoundland, A1C 5X1 Canada
| | - M. Van Wyngaarden
- Biology Department Dalhousie University 1355 Oxford Street Halifax Nova Scotia
| | - S. Duffy
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, 80 E White Hills Rd St. John’s, Newfoundland, A1C 5X1 Canada
| | - A. Messmer
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, 80 E White Hills Rd St. John’s, Newfoundland, A1C 5X1 Canada
| | - B. Wringe
- Bedford Institute of Oceanography Fisheries and Oceans Canada Dartmouth NS Canada
| | - S. Karoliussen
- Centre for Integrative Genetics Norwegian University of Life Sciences Ås Norway
| | - J. B. Dempson
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, 80 E White Hills Rd St. John’s, Newfoundland, A1C 5X1 Canada
| | - I. A. Fleming
- Department of Ocean Sciences, Ocean Sciences Centre Memorial University of Newfoundland St John’s, NL, A1C 5S7 Canada
| | - M. F. Solberg
- Institute of Marine Research Population Genetics Research Group PO Box 1870, Nordnes, N‐5817 Bergen Norway
| | - K. A. Glover
- Institute of Marine Research Population Genetics Research Group PO Box 1870, Nordnes, N‐5817 Bergen Norway
- Department of Biological Sciences University of Bergen N‐5020 Bergen Norway
| | - P. Bentzen
- Biology Department Dalhousie University 1355 Oxford Street Halifax Nova Scotia
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6
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Assessing Genetic Variation in Wild and Domesticated Pikeperch Populations: Implications for Conservation and Fish Farming. Animals (Basel) 2022; 12:ani12091178. [PMID: 35565604 PMCID: PMC9102197 DOI: 10.3390/ani12091178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/19/2022] [Accepted: 04/27/2022] [Indexed: 12/30/2022] Open
Abstract
Simple Summary The pikeperch Sander lucioperca (Linnaeus, 1758) is an important fish species in the development of European aquaculture. The aquaculture of a fish species can be facilitated by knowing the genetic variability within and among populations. Here, we assessed the genetic background of 8 wild populations along with 13 broodstocks (i.e., from fish farms) of pikeperch through a combination of genetic markers. We underlined that current broodstocks have a genetic diversity similar to wild populations. When focusing on genetic differentiation, we highlight that European pikeperch populations are divided into two groups: one predominantly present in Northern Europe and around the Baltic Sea and another mainly in Central Europe. Broodstocks appear to contain fish of a single origin with only a few exceptions. Ultimately, we have proposed baseline information about genetic diversity of pikeperch along with a genetic tool that can help pikeperch producers manage and improve their fish stock. Abstract The pikeperch is a freshwater/brackish water fish species with growing interest for European aquaculture. Wild populations show signs of decline in many areas of the species natural range due to human activities. The comparative evaluation of genetic status in wild and domesticated populations is extremely useful for the future establishment of genetic breeding programs. The main objective of the present study was to assess and compare the genetic variability of 13 domesticated populations from commercial farms and 8 wild populations, developing an efficient microsatellite multiplex tool for genotyping. Partial cytochrome b gene sequences were also used to infer phylogeographic relationships. Results show that on average, the domesticated populations do not exhibit significantly lower levels of genetic diversity compared to the wild ones and do not suffer from inbreeding. Nuclear data provide evidence that pikeperch populations in Europe belong to at least two genetically differentiated groups: the first one is predominantly present in Northern Europe and around the Baltic Sea, while the second one comprises populations from Central Europe. In this second group, Hungarian origin populations constitute a differentiated stock that needs special consideration. Aquaculture broodstocks analyzed appear to contain fish of a single origin with only a few exceptions.
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Harvey A, Skaala Ø, Borgstrøm R, Fjeldheim PT, Christine Andersen K, Rong Utne K, Askeland Johnsen I, Fiske P, Winterthun S, Knutar S, Sægrov H, Urdal K, Alan Glover K. Time series covering up to four decades reveals major changes and drivers of marine growth and proportion of repeat spawners in an Atlantic salmon population. Ecol Evol 2022; 12:e8780. [PMID: 35386868 PMCID: PMC8976282 DOI: 10.1002/ece3.8780] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 03/03/2022] [Accepted: 03/10/2022] [Indexed: 11/10/2022] Open
Abstract
Wild Atlantic salmon populations have declined in many regions and are affected by diverse natural and anthropogenic factors. To facilitate management guidelines, precise knowledge of mechanisms driving population changes in demographics and life history traits is needed.Our analyses were conducted on (a) age and growth data from scales of salmon caught by angling in the river Etneelva, Norway, covering smolt year classes from 1980 to 2018, (b) extensive sampling of the whole spawning run in the fish trap from 2013 onwards, and (c) time series of sea surface temperature, zooplankton biomass, and salmon lice infestation intensity.Marine growth during the first year at sea displayed a distinct stepwise decline across the four decades. Simultaneously, the population shifted from predominantly 1SW to 2SW salmon, and the proportion of repeat spawners increased from 3 to 7%. The latter observation is most evident in females and likely due to decreased marine exploitation. Female repeat spawners tended to be less catchable than males by anglers.Depending on the time period analyzed, marine growth rate during the first year at sea was both positively and negatively associated with sea surface temperature. Zooplankton biomass was positively associated with growth, while salmon lice infestation intensity was negatively associated with growth.Collectively, these results are likely to be linked with both changes in oceanic conditions and harvest regimes. Our conflicting results regarding the influence of sea surface temperature on marine growth are likely to be caused by long-term increases in temperature, which may have triggered (or coincided with) ecosystem shifts creating generally poorer growth conditions over time, but within shorter datasets warmer years gave generally higher growth. We encourage management authorities to expand the use of permanently monitored reference rivers with complete trapping facilities, like the river Etneelva, generating valuable long-term data for future analyses.
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Affiliation(s)
| | | | - Reidar Borgstrøm
- Faculty of Environmental Sciences and Natural Resource ManagementÅsNorway
| | | | | | | | | | - Peder Fiske
- Norwegian Institute for Nature ResearchTrondheimNorway
| | | | | | | | | | - Kevin Alan Glover
- Institute of Marine ResearchBergenNorway
- Department of BiologyUniversity of BergenBergenNorway
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8
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Besnier F, Ayllon F, Skaala Ø, Solberg MF, Fjeldheim PT, Anderson K, Knutar S, Glover KA. Introgression of domesticated salmon changes life history and phenology of a wild salmon population. Evol Appl 2022; 15:853-864. [PMID: 35603027 PMCID: PMC9108307 DOI: 10.1111/eva.13375] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 03/03/2022] [Accepted: 03/09/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- F. Besnier
- Institute of Marine Research PO box 1870 Nordnes N‐5817 Norway
| | - F. Ayllon
- Institute of Marine Research PO box 1870 Nordnes N‐5817 Norway
| | - Ø. Skaala
- Institute of Marine Research PO box 1870 Nordnes N‐5817 Norway
| | - M. F. Solberg
- Institute of Marine Research PO box 1870 Nordnes N‐5817 Norway
| | | | - K. Anderson
- Institute of Marine Research PO box 1870 Nordnes N‐5817 Norway
| | - S. Knutar
- Institute of Marine Research PO box 1870 Nordnes N‐5817 Norway
| | - K. A. Glover
- Institute of Marine Research PO box 1870 Nordnes N‐5817 Norway
- Department of Biological Sciences University of Bergen N‐5020 Bergen Norway
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9
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Vollset KW, Urdal K, Utne K, Thorstad EB, Sægrov H, Raunsgard A, Skagseth Ø, Lennox RJ, Østborg GM, Ugedal O, Jensen AJ, Bolstad GH, Fiske P. Ecological regime shift in the Northeast Atlantic Ocean revealed from the unprecedented reduction in marine growth of Atlantic salmon. SCIENCE ADVANCES 2022; 8:eabk2542. [PMID: 35245115 PMCID: PMC8896796 DOI: 10.1126/sciadv.abk2542] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
Ecological regime shifts are abrupt changes in the structure and function of ecosystems that persist over time, but evidence of contemporary regime shifts are rare. Historical scale data from 52,384 individual wild Atlantic salmon caught in 180 rivers from 1989 to 2017 reveal that growth of Atlantic salmon across the Northeast Atlantic Ocean abruptly decreased following the year 2004. At the same time, the proportion of early maturing Atlantic salmon decreased. These changes occurred after a marked decrease in the extent of Arctic water in the Norwegian Sea, a subsequent warming of spring water temperature before Atlantic salmon entering the sea, and an approximately 50% reduction of zooplankton across large geographic areas of the Northeast Atlantic Ocean. A sudden decrease in growth was also observed among Atlantic mackerel in the Norwegian Sea. Our results point toward an ecosystem-scale regime shift in the Northeast Atlantic Ocean.
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Affiliation(s)
- Knut Wiik Vollset
- Norwegian Research Centre (NORCE), Laboratory for Freshwater Ecology and Inland Fisheries, 5008 Bergen, Norway
| | - Kurt Urdal
- Rådgivende Biologer AS, 5059 Bergen, Norway
| | - Kjell Utne
- Institute of Marine Research, 5817 Bergen, Norway
| | - Eva B. Thorstad
- Norwegian Institute for Nature Research (NINA), 7485 Trondheim, Norway
| | | | - Astrid Raunsgard
- Norwegian Institute for Nature Research (NINA), 7485 Trondheim, Norway
| | | | - Robert J. Lennox
- Norwegian Research Centre (NORCE), Laboratory for Freshwater Ecology and Inland Fisheries, 5008 Bergen, Norway
- Norwegian Institute for Nature Research (NINA), 7485 Trondheim, Norway
| | - Gunnel M. Østborg
- Norwegian Institute for Nature Research (NINA), 7485 Trondheim, Norway
| | - Ola Ugedal
- Norwegian Institute for Nature Research (NINA), 7485 Trondheim, Norway
| | - Arne J. Jensen
- Norwegian Institute for Nature Research (NINA), 7485 Trondheim, Norway
| | - Geir H. Bolstad
- Norwegian Institute for Nature Research (NINA), 7485 Trondheim, Norway
| | - Peder Fiske
- Norwegian Institute for Nature Research (NINA), 7485 Trondheim, Norway
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10
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Islam SS, Xue X, Caballero-Solares A, Bradbury IR, Rise ML, Fleming IA. Distinct early life stage gene expression effects of hybridization among European and North American farmed and wild Atlantic salmon populations. Mol Ecol 2022; 31:2712-2729. [PMID: 35243721 DOI: 10.1111/mec.16418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 01/29/2022] [Accepted: 02/21/2022] [Indexed: 11/27/2022]
Abstract
Due to multi-generation domestication selection, farmed and wild Atlantic salmon diverge genetically, which raises concerns about potential genetic interactions among escaped farmed and wild populations and disruption of local adaptation through introgression. When farmed strains of distant geographic origin are used, it is unknown whether the genetic consequences posed by escaped farmed fish will be greater than if more locally derived strains are used. Quantifying gene transcript expression differences among divergent farmed, wild and F1 hybrids under controlled conditions is one of the ways to explore the consequences of hybridization. We compared the transcriptomes of fry at the end of yolk sac absorption of a European (EO) farmed ("StofnFiskur", Norwegian strain), a North American (NA) farmed (Saint John River, NB strain), a Newfoundland (NF) wild population with EO ancestry, and related F1 hybrids using 44K microarrays. Our findings indicate that the wild population showed greater transcriptome differences from the EO farmed strain than that of the NA farmed strain. We also found the largest differences in global gene expression between the two farmed strains. We detected the fewest differentially expressed transcripts between F1 hybrids and domesticated/wild maternal strains. We also found that the differentially expressed genes between cross types over-represented GO terms associated with metabolism, development, growth, immune response, and redox homeostasis processes. These findings suggest that the interbreeding of escaped EO/NA farmed and NF wild population would alter gene transcription, and the consequences of hybridization would be greater from escaped EO farmed than NA farmed salmon, resulting in potential effects on the wild populations.
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Affiliation(s)
- Shahinur S Islam
- Department of Ocean Sciences, Ocean Sciences Centre, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada
| | - Xi Xue
- Department of Ocean Sciences, Ocean Sciences Centre, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada
| | - Albert Caballero-Solares
- Department of Ocean Sciences, Ocean Sciences Centre, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada
| | - Ian R Bradbury
- Department of Ocean Sciences, Ocean Sciences Centre, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada.,Salmonids Section, Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, 80 East White Hills Road, St. John's, NL, A1C 5X, Canada
| | - Matthew L Rise
- Department of Ocean Sciences, Ocean Sciences Centre, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada
| | - Ian A Fleming
- Department of Ocean Sciences, Ocean Sciences Centre, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada
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11
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Bolstad GH, Karlsson S, Hagen IJ, Fiske P, Urdal K, Sægrov H, Florø-Larsen B, Sollien VP, Østborg G, Diserud OH, Jensen AJ, Hindar K. Introgression from farmed escapees affects the full life cycle of wild Atlantic salmon. SCIENCE ADVANCES 2021; 7:eabj3397. [PMID: 34936452 PMCID: PMC8694624 DOI: 10.1126/sciadv.abj3397] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 11/03/2021] [Indexed: 05/28/2023]
Abstract
After a half a century of salmon farming, we have yet to understand how the influx of genes from farmed escapees affects the full life history of Atlantic salmon (Salmo salar L.) in the wild. Using scale samples of over 6900 wild adult salmon from 105 rivers, we document that increased farmed genetic ancestry is associated with increased growth throughout life and a younger age at both seaward migration and sexual maturity. There was large among-population variation in the effects of introgression. Most saliently, the increased growth at sea following introgression declined with the population’s average growth potential. Variation at two major-effect loci associated with age at maturity was little affected by farmed genetic ancestry and could not explain the observed phenotypic effects of introgression. Our study provides knowledge crucial for predicting the ecological and evolutionary consequences of increased aquaculture production worldwide.
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Affiliation(s)
- Geir H. Bolstad
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Sten Karlsson
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Ingerid J. Hagen
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Peder Fiske
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Kurt Urdal
- Rådgivende Biologer, NO-5059 Bergen, Norway
| | | | | | | | - Gunnel Østborg
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Ola H. Diserud
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Arne J. Jensen
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Kjetil Hindar
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
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12
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Cucherousset J, Sundt-Hansen LE, Buoro M, Závorka L, Lassus R, Baekkelie KAE, Fleming IA, Björnsson BT, Johnsson JI, Hindar K. Growth-enhanced salmon modify stream ecosystem functioning. JOURNAL OF FISH BIOLOGY 2021; 99:1978-1989. [PMID: 34495559 DOI: 10.1111/jfb.14904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 08/10/2021] [Accepted: 08/28/2021] [Indexed: 06/13/2023]
Abstract
Use of fast-growing domesticated and/or genetically modified strains of fish is becoming increasingly common in aquaculture, increasing the likelihood of deliberate or accidental introductions into the wild. To date, their ecological impacts on ecosystems remain to be quantified. Here, using a controlled phenotype manipulation by implanting growth hormone in juvenile Atlantic salmon (Salmo salar), we found that growth-enhanced fish display changes in several phenotypic traits known to be important for ecosystem functioning, such as habitat use, morphology and excretion rate. Furthermore, these phenotypic changes were associated with significant impacts on the invertebrate community and key stream ecosystem functions such as primary production and leaf-litter decomposition. These findings provide novel evidence that introductions of growth-enhanced fish into the wild can affect the functioning of natural ecosystems and represent a form of intraspecific invasion. Consequently, environmental impact assessments of growth-enhanced organisms need to explicitly consider ecosystem-level effects.
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Affiliation(s)
- Julien Cucherousset
- Laboratoire Évolution and Diversité Biologique (EDB UMR 5174), Université de Toulouse, CNRS, ENFA, UPS, Toulouse, France
| | | | - Mathieu Buoro
- Laboratoire Évolution and Diversité Biologique (EDB UMR 5174), Université de Toulouse, CNRS, ENFA, UPS, Toulouse, France
- ECOBIOP, Université de Pau et des Pays de l'Adour, E2S UPPA, INRAE, Saint-Pée-sur-Nivelle, France
| | - Libor Závorka
- Laboratoire Évolution and Diversité Biologique (EDB UMR 5174), Université de Toulouse, CNRS, ENFA, UPS, Toulouse, France
| | - Rémy Lassus
- Laboratoire Évolution and Diversité Biologique (EDB UMR 5174), Université de Toulouse, CNRS, ENFA, UPS, Toulouse, France
| | | | - Ian A Fleming
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | | | - Jörgen I Johnsson
- Department of Biological & Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Kjetil Hindar
- Norwegian Institute for Nature Research, Trondheim, Norway
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13
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Perry WB. Turbo charged salmon and stream ecosystem function: the plight of aquaculture escapees. JOURNAL OF FISH BIOLOGY 2021; 99:1777. [PMID: 34951020 DOI: 10.1111/jfb.14954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/24/2021] [Accepted: 11/25/2021] [Indexed: 06/14/2023]
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14
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Andrew King R, Miller AL, Stevens JR. Has stocking contributed to an increase in the rod catch of anadromous trout (Salmo trutta L.) in the Shetland Islands, UK? JOURNAL OF FISH BIOLOGY 2021; 99:980-989. [PMID: 33991118 DOI: 10.1111/jfb.14784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/11/2021] [Indexed: 06/12/2023]
Abstract
The stocking of hatchery-origin fish into rivers and lakes has long been used in fisheries management to try to enhance catches, especially for trout and salmon species. Frequently, however, the long-term impacts of stocking programmes have not been evaluated. In this study, the authors investigate the contribution of a stocking programme undertaken to support the rod catch of sea trout in the Shetland Islands, UK. Once a highly productive recreational fishery, Shetland sea trout catches crashed in the mid-1990s. Around the time that stocking began, increases in rod catches were also reported, with advocates of the stocking highlighting the apparent success of the programme. Using a suite of genetic markers (microsatellites), this study explores the contribution of the stocking programme to the Shetland sea trout population. The authors found that the domesticated broodstock and wild spawned brown trout from seven streams were genetically distinct. Despite extensive stocking, wild spawned brown trout dominated, even in those streams with a long history of supplementation. The majority of sea trout caught and analysed were of wild origin - only a single individual was of pure stocked origin, with a small number of fish being of wild × stocked origins. This study suggests that stocking with a domesticated strain of brown trout has made only a very limited contribution to the Shetland Islands rod catch, and that the revival of sea trout numbers appears to be driven almost exclusively by recovery of trout spawned in the wild.
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Affiliation(s)
- R Andrew King
- College of Life and Environmental Sciences, Hatherly Building, University of Exeter, Exeter, UK
| | - Andrew L Miller
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR
- North Atlantic Fisheries College Marine Centre, University of the Highlands and Islands, Scalloway, Shetland, UK
| | - Jamie R Stevens
- College of Life and Environmental Sciences, Hatherly Building, University of Exeter, Exeter, UK
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15
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Perry WB, Kaufmann J, Solberg MF, Brodie C, Coral Medina AM, Pillay K, Egerton A, Harvey A, Phillips KP, Coughlan J, Egan F, Grealis R, Hutton S, Leseur F, Ryan S, Poole R, Rogan G, Ryder E, Schaal P, Waters C, Wynne R, Taylor M, Prodöhl P, Creer S, Llewellyn M, McGinnity P, Carvalho G, Glover KA. Domestication-induced reduction in eye size revealed in multiple common garden experiments: The case of Atlantic salmon ( Salmo salar L.). Evol Appl 2021; 14:2319-2332. [PMID: 34603501 PMCID: PMC8477603 DOI: 10.1111/eva.13297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 08/24/2021] [Indexed: 11/28/2022] Open
Abstract
Domestication leads to changes in traits that are under directional selection in breeding programmes, though unintentional changes in nonproduction traits can also arise. In offspring of escaping fish and any hybrid progeny, such unintentionally altered traits may reduce fitness in the wild. Atlantic salmon breeding programmes were established in the early 1970s, resulting in genetic changes in multiple traits. However, the impact of domestication on eye size has not been studied. We measured body size corrected eye size in 4000 salmon from six common garden experiments conducted under artificial and natural conditions, in freshwater and saltwater environments, in two countries. Within these common gardens, offspring of domesticated and wild parents were crossed to produce 11 strains, with varying genetic backgrounds (wild, domesticated, F1 hybrids, F2 hybrids and backcrosses). Size-adjusted eye size was influenced by both genetic and environmental factors. Domesticated fish reared under artificial conditions had smaller adjusted eye size when compared to wild fish reared under identical conditions, in both the freshwater and marine environments, and in both Irish and Norwegian experiments. However, in parr that had been introduced into a river environment shortly after hatching and sampled at the end of their first summer, differences in adjusted eye size observed among genetic groups were of a reduced magnitude and were nonsignificant in 2-year-old sea migrating smolts sampled in the river immediately prior to sea entry. Collectively, our findings could suggest that where natural selection is present, individuals with reduced eye size are maladapted and consequently have reduced fitness, building on our understanding of the mechanisms that underlie a well-documented reduction in the fitness of the progeny of domesticated salmon, including hybrid progeny, in the wild.
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Affiliation(s)
- William Bernard Perry
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
- Water Research InstituteSchool of BiosciencesCardiff UniversityCardiffUK
- Population Genetics Research GroupInstitute of Marine ResearchBergenNorway
| | - Joshka Kaufmann
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | | | - Christopher Brodie
- Ecosystems and Environment Research CentreSchool of Environment and Life SciencesUniversity of SalfordSalfordUK
| | | | - Kirthana Pillay
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
| | - Anna Egerton
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
| | - Alison Harvey
- Population Genetics Research GroupInstitute of Marine ResearchBergenNorway
| | - Karl P. Phillips
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Jamie Coughlan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Fintan Egan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Ronan Grealis
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Steve Hutton
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Floriane Leseur
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Sarah Ryan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | | | - Ger Rogan
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Elizabeth Ryder
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Patrick Schaal
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
- Institute of BiodiversityAnimal Health & Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Catherine Waters
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Robert Wynne
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Martin Taylor
- School of Biological SciencesUniversity of East AngliaNorwichUK
| | - Paulo Prodöhl
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen’s UniversityBelfastUK
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
| | - Martin Llewellyn
- Institute of BiodiversityAnimal Health & Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Philip McGinnity
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Gary Carvalho
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
| | - Kevin Alan Glover
- Population Genetics Research GroupInstitute of Marine ResearchBergenNorway
- Institute of BiologyUniversity of BergenBergenNorway
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16
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Revathi Venkateswaran V, Roth O, Gokhale CS. Consequences of combining sex-specific traits. Evolution 2021; 75:1274-1287. [PMID: 33759452 DOI: 10.1111/evo.14204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 02/12/2021] [Indexed: 12/22/2022]
Abstract
Males and females follow distinct life-history strategies that have co-evolved with several sex-specific traits. Higher investment into parental investment (PI) demands an increased lifespan. Thus, resource allocation toward an efficient immune system is mandatory. In contrast, resources allocated toward secondary sexual signals (ornamentation) may negatively correlate with investment into immunity and ultimately result in a shorter lifespan. Previous studies have addressed how resource allocation toward single sex-specific traits impacts lifetime reproductive success (LRS). However, the trade-offs between diverse sex-specific characteristics and their impact on LRS remain largely unassessed impeding our understanding of life-history evolution. We have designed a theoretical framework (informed by experimental data and evolutionary genetics) that explores the effects of multiple sex-specific traits and assessed how they influence LRS. From the individual sex-specific traits, we inferred the consequences at the population level by evaluating adult sex ratios (ASR). Our theory implies that sex-specific resource allocation toward the assessed traits resulted in a biased ASR. Our model focuses on the impact of PI, ornamentation, and immunity as causal to biased ASR. The framework developed herein can be employed to understand the combined impact of diverse sex-specific traits on the LRS and the eventual population dynamics of particular model systems.
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Affiliation(s)
- Vandana Revathi Venkateswaran
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, August Thienemann Str. 2, Plön, 24306, Germany
| | - Olivia Roth
- GEOMAR - Helmholtz Center for Ocean Research, Düsternbrookerweg 20, Kiel, D-24105, Germany
| | - Chaitanya S Gokhale
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, August Thienemann Str. 2, Plön, 24306, Germany
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17
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Wacker S, Aronsen T, Karlsson S, Ugedal O, Diserud OH, Ulvan EM, Hindar K, Næsje TF. Selection against individuals from genetic introgression of escaped farmed salmon in a natural population of Atlantic salmon. Evol Appl 2021; 14:1450-1460. [PMID: 34025778 PMCID: PMC8127704 DOI: 10.1111/eva.13213] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 01/14/2021] [Accepted: 02/26/2021] [Indexed: 11/27/2022] Open
Abstract
The viability of wild Atlantic salmon populations is threatened by genetic introgression from escaped farmed salmon. Farmed Atlantic salmon are genetically improved for important commercial traits and a life in captivity but are poorly adapted to the natural environment. The rate of gene flow from escaped farmed to wild salmon depends on their spawning success and on offspring survival at various life stages. We here investigate relative survival of introgressed juvenile Atlantic salmon (parr) in a river in northern Norway. The studied population has experienced genetic introgression from farmed salmon for about four generations (20 years). We followed two cohorts of parr from the year of hatching (0+) to the age of 2 years (2+). Farmed genetic introgression was quantified at the individual level and on a continuous scale using diagnostic SNPs. Population-level genetic introgression decreased from 0+ to 2+ by 64% (2011 cohort) and 37% (2013 cohort). This change was driven by a 70% (2011 cohort) and 49% (2013 cohort) lower survival from age 0+ to 2+ in introgressed parr compared to parr of wild origin. Our observations show that there is natural selection against genetic introgression with a potential cost of lower productivity.
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Affiliation(s)
| | - Tonje Aronsen
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Sten Karlsson
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Ola Ugedal
- Norwegian Institute for Nature ResearchTrondheimNorway
| | | | - Eva M. Ulvan
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Kjetil Hindar
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Tor F. Næsje
- Norwegian Institute for Nature ResearchTrondheimNorway
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18
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Perry WB, Solberg MF, Brodie C, Medina AC, Pillay KG, Egerton A, Harvey A, Creer S, Llewellyn M, Taylor M, Carvalho G, Glover KA. Disentangling the effects of sex, life history and genetic background in Atlantic salmon: growth, heart and liver under common garden conditions. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200811. [PMID: 33204455 PMCID: PMC7657880 DOI: 10.1098/rsos.200811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
Livestock domestication has long been a part of agriculture, estimated to have first occurred approximately 10 000 years ago. Despite the plethora of traits studied, there is little understanding of the possible impacts domestication has had on internal organs, which are key determinants of survival. Moreover, the genetic basis of observed associated changes in artificial environments is still puzzling. Here we examine impacts of captivity on two organs in Atlantic salmon (Salar salar) that have been domesticated for approximately 50 years: heart and liver, in addition to growth. We studied multiple families of wild, domesticated, F1 and F2 hybrid, and backcrossed strains of S. salar in replicated common garden tanks during the freshwater and marine stages of development. Heart and liver weight were investigated, along with heart morphology metrics examined in just the wild, domesticated and F1 hybrid strains (heart height and width). Growth was positively linked with the proportion of the domesticated strain, and recombination in F2 hybrids (and the potential disruption of co-adapted gene complexes) did not influence growth. Despite the influence of domestication on growth, we found no evidence for domestication-driven divergence in heart or liver morphology. However, sexual dimorphism was detected in heart morphology, and after controlling for body size, females exhibited significantly larger heart weight and heart width when compared with males. Wild females also had an increased heart height when compared with wild males, and this was not observed in any other strain. Females sampled in saltwater showed significantly larger heart height with rounder hearts, than saltwater males. Collectively, these results demonstrate an additive basis of growth and, despite a strong influence of domestication on growth, no clear evidence of changes in heart or liver morphology associated with domestication was identified.
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Affiliation(s)
- William Bernard Perry
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Monica F. Solberg
- Population Genetics Research Group, Institute of Marine Research, PO Box 1870, Nordnes 5817, Bergen, Norway
| | - Christopher Brodie
- Mariani Molecular Ecology Laboratory, School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool L3 5UX, UK
| | - Angela C. Medina
- School of Microbiology, Food Science and Technology Building University College Cork, Cork T12 TP07, Ireland
| | - Kirthana G. Pillay
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Anna Egerton
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Alison Harvey
- Population Genetics Research Group, Institute of Marine Research, PO Box 1870, Nordnes 5817, Bergen, Norway
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Martin Llewellyn
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Martin Taylor
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Gary Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Kevin A. Glover
- Population Genetics Research Group, Institute of Marine Research, PO Box 1870, Nordnes 5817, Bergen, Norway
- Institute of Biology, University of Bergen, Bergen, Norway
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19
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Islam SS, Wringe BF, Bradbury IR, Fleming IA. Behavioural variation among divergent European and North American farmed and wild Atlantic salmon (Salmo salar) populations. Appl Anim Behav Sci 2020. [DOI: 10.1016/j.applanim.2020.105029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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20
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Bicskei B, Taggart JB, Bron JE, Glover KA. Transcriptomic comparison of communally reared wild, domesticated and hybrid Atlantic salmon fry under stress and control conditions. BMC Genet 2020; 21:57. [PMID: 32471356 PMCID: PMC7257211 DOI: 10.1186/s12863-020-00858-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 05/12/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Domestication is the process by which organisms become adapted to the human-controlled environment. Since the selection pressures that act upon cultured and natural populations differ, adaptations that favour life in the domesticated environment are unlikely to be advantageous in the wild. Elucidation of the differences between wild and domesticated Atlantic salmon may provide insights into some of the genomic changes occurring during domestication, and, help to predict the evolutionary consequences of farmed salmon escapees interbreeding with wild conspecifics. In this study the transcriptome of the offspring of wild and domesticated Atlantic salmon were compared using a common-garden experiment under standard hatchery conditions and in response to an applied crowding stressor. RESULTS Transcriptomic differences between wild and domesticated crosses were largely consistent between the control and stress conditions, and included down-regulation of environmental information processing, immune and nervous system pathways and up-regulation of genetic information processing, carbohydrate metabolism, lipid metabolism and digestive and endocrine system pathways in the domesticated fish relative to their wild counterparts, likely reflective of different selection pressures acting in wild and cultured populations. Many stress responsive functions were also shared between crosses and included down-regulation of cellular processes and genetic information processing and up-regulation of some metabolic pathways, lipid and energy in particular. The latter may be indicative of mobilization and reallocation of energy resources in response to stress. However, functional analysis indicated that a number of pathways behave differently between domesticated and wild salmon in response to stress. Reciprocal F1 hybrids permitted investigation of inheritance patterns that govern transcriptomic differences between these genetically divergent crosses. Additivity and maternal dominance accounted for approximately 42 and 25% of all differences under control conditions for both hybrids respectively. However, the inheritance of genes differentially expressed between crosses under stress was less consistent between reciprocal hybrids, potentially reflecting maternal environmental effects. CONCLUSION We conclude that there are transcriptomic differences between the domesticated and wild salmon strains studied here, reflecting the different selection pressures operating on them. Our results indicate that stress may affect certain biological functions differently in wild, domesticated and hybrid crosses and these should be further investigated.
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Affiliation(s)
- Beatrix Bicskei
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA UK
| | - John B. Taggart
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA UK
| | - James E. Bron
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA UK
| | - Kevin A. Glover
- Institute of Marine Research, Bergen, Norway
- Department of Biology, University of Bergen, Bergen, Norway
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21
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Naval-Sanchez M, McWilliam S, Evans B, Yáñez JM, Houston RD, Kijas JW. Changed Patterns of Genomic Variation Following Recent Domestication: Selection Sweeps in Farmed Atlantic Salmon. Front Genet 2020; 11:264. [PMID: 32318091 PMCID: PMC7147387 DOI: 10.3389/fgene.2020.00264] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/05/2020] [Indexed: 12/30/2022] Open
Abstract
The introduction of wild Atlantic salmon into captivity, and their subsequent artificial selection for production traits, has caused phenotypic differences between domesticated fish and their wild counterparts. Identification of regions of the genome underling these changes offers the promise of characterizing the early biological consequences of domestication. In the current study, we sequenced a population of farmed European Atlantic salmon and compared the observed patterns of SNP variation to those found in conspecific wild populations. This identified 139 genomic regions that contained significantly elevated SNP homozygosity in farmed fish when compared to their wild counterparts. The most extreme was adjacent to versican, a gene involved in control of neural crest cell migration. To control for false positive signals, a second and independent dataset of farmed and wild European Atlantic salmon was assessed using the same methodology. A total of 81 outlier regions detected in the first dataset showed significantly reduced homozygosity within the second one, strongly suggesting the genomic regions identified are enriched for true selection sweeps. Examination of the associated genes identified a number previously characterized as targets of selection in other domestic species and that have roles in development, behavior and olfactory system. These include arcvf, sema6, errb4, id2-like, and 6n1-like genes. Finally, we searched for evidence of parallel sweeps using a farmed population of North American origin. This failed to detect a convincing overlap to the putative sweeps present in European populations, suggesting the factors that drive patterns of variation under domestication and early artificial selection were largely independent. This is the first analysis on domestication of aquaculture species exploiting whole-genome sequence data and resulted in the identification of sweeps common to multiple independent populations of farmed European Atlantic salmon.
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Affiliation(s)
| | | | - Bradley Evans
- Salmon Enterprises of Tasmania Pty. Limited, Wayatinah, TAS, Australia
| | - José M Yáñez
- Faculty of Veterinary and Animal Sciences, University of Chile, Santiago, Chile
| | - Ross D Houston
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom
| | - James W Kijas
- CSIRO Agriculture and Food, Brisbane, QLD, Australia
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22
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Harvey AC, Glover KA, Wennevik V, Skaala Ø. Atlantic salmon and sea trout display synchronised smolt migration relative to linked environmental cues. Sci Rep 2020; 10:3529. [PMID: 32103141 PMCID: PMC7044379 DOI: 10.1038/s41598-020-60588-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 02/14/2020] [Indexed: 11/09/2022] Open
Abstract
Anadromous salmon and sea trout smolts face challenging migrations from freshwater to the marine environment characterised by high mortality. Therefore, the timing of smolt migration is likely to be critical for survival. Time-series comparing migration of Atlantic salmon and sea trout smolts in the same river, and their response to the same environmental cues, are scarce. Here, we analysed migration timing of ~41 000 Atlantic salmon and sea trout smolts over a 19-year period from the river Guddalselva, western Norway. Trout displayed a longer migration window in earlier years, which decreased over time to become more similar to the salmon migration window. On average, salmon migrated out of the river earlier than trout. Migration of both species was significantly influenced by river water temperature and water discharge, but their relative influence varied across the years. On average, body-length of smolts of both species overlapped, however, size differences were observed within the migration period and among the years. We conclude that salmon and trout smolts in this river are highly synchronised and migrate in response to the same range of linked environmental cues.
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Affiliation(s)
| | - Kevin A Glover
- Institute of Marine Research (IMR), Bergen, Norway.,Institute of Biology, University of Bergen, Bergen, Norway
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23
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Besnier F, Solberg MF, Harvey AC, Carvalho GR, Bekkevold D, Taylor MI, Creer S, Nielsen EE, Skaala Ø, Ayllon F, Dahle G, Glover KA. Epistatic regulation of growth in Atlantic salmon revealed: a QTL study performed on the domesticated-wild interface. BMC Genet 2020; 21:13. [PMID: 32033538 PMCID: PMC7006396 DOI: 10.1186/s12863-020-0816-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 01/28/2020] [Indexed: 12/23/2022] Open
Abstract
Background Quantitative traits are typically considered to be under additive genetic control. Although there are indications that non-additive factors have the potential to contribute to trait variation, experimental demonstration remains scarce. Here, we investigated the genetic basis of growth in Atlantic salmon by exploiting the high level of genetic diversity and trait expression among domesticated, hybrid and wild populations. Results After rearing fish in common-garden experiments under aquaculture conditions, we performed a variance component analysis in four mapping populations totaling ~ 7000 individuals from six wild, two domesticated and three F1 wild/domesticated hybrid strains. Across the four independent datasets, genome-wide significant quantitative trait loci (QTLs) associated with weight and length were detected on a total of 18 chromosomes, reflecting the polygenic nature of growth. Significant QTLs correlated with both length and weight were detected on chromosomes 2, 6 and 9 in multiple datasets. Significantly, epistatic QTLs were detected in all datasets. Discussion The observed interactions demonstrated that the phenotypic effect of inheriting an allele deviated between half-sib families. Gene-by-gene interactions were also suggested, where the combined effect of two loci resulted in a genetic effect upon phenotypic variance, while no genetic effect was detected when the two loci were considered separately. To our knowledge, this is the first documentation of epistasis in a quantitative trait in Atlantic salmon. These novel results are of relevance for breeding programs, and for predicting the evolutionary consequences of domestication-introgression in wild populations.
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Affiliation(s)
- Francois Besnier
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.
| | - Monica F Solberg
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Alison C Harvey
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, UK
| | - Gary R Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, UK
| | - Dorte Bekkevold
- Section for Marine Living Resources, National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Martin I Taylor
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, UK
| | - Einar E Nielsen
- Section for Marine Living Resources, National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Øystein Skaala
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Fernando Ayllon
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Geir Dahle
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen, Norway
| | - Kevin A Glover
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen, Norway
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24
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Solberg MF, Robertsen G, Sundt-Hansen LE, Hindar K, Glover KA. Domestication leads to increased predation susceptibility. Sci Rep 2020; 10:1929. [PMID: 32029847 PMCID: PMC7005312 DOI: 10.1038/s41598-020-58661-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 01/19/2020] [Indexed: 12/18/2022] Open
Abstract
Domestication involves adapting animals to the human-controlled environment. Genetic changes occurring during the domestication process may manifest themselves in phenotypes that render domesticated animals maladaptive for life in the wild. Domesticated Atlantic salmon frequently interbreed with wild conspecifics, and their offspring display reduced survival in the wild. However, the mechanism(s) contributing to their lower survival in the wild remains a subject of conjecture. Here, we document higher susceptibility to predation by brown trout in fast-growing domesticated salmon, as compared to their slow-growing wild conspecifics, demonstrating that directional selection for increased growth comes at a cost of decreased survival when under the risk of predation, as predicted by the growth/predation risk trade-off. Despite earlier documentation of altered risk-taking behavior, this study demonstrates for the first time that domestication of Atlantic salmon has lead to increased predation susceptibility, and that this consitutes a mechanism underpinning the observed survial differences in the wild.
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Affiliation(s)
- Monica F Solberg
- Institute of Marine Research, P.O. Box 1870 Nordnes, NO, 5817, Bergen, Norway.
| | - Grethe Robertsen
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, NO, 7485, Trondheim, Norway
| | - Line E Sundt-Hansen
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, NO, 7485, Trondheim, Norway
| | - Kjetil Hindar
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, NO, 7485, Trondheim, Norway
| | - Kevin A Glover
- Institute of Marine Research, P.O. Box 1870 Nordnes, NO, 5817, Bergen, Norway.,Department of Biology, University of Bergen, Bergen, Norway
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25
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Tamario C, Sunde J, Petersson E, Tibblin P, Forsman A. Ecological and Evolutionary Consequences of Environmental Change and Management Actions for Migrating Fish. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00271] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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26
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Skaala Ø, Besnier F, Borgstrøm R, Barlaup B, Sørvik AG, Normann E, Østebø BI, Hansen MM, Glover KA. An extensive common-garden study with domesticated and wild Atlantic salmon in the wild reveals impact on smolt production and shifts in fitness traits. Evol Appl 2019; 12:1001-1016. [PMID: 31080511 PMCID: PMC6503829 DOI: 10.1111/eva.12777] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/18/2019] [Accepted: 01/19/2019] [Indexed: 01/15/2023] Open
Abstract
Interactions between domesticated escapees and wild conspecifics represent a threat to the genetic integrity and fitness of native populations. For Atlantic salmon, the recurrent presence of large numbers of domesticated escapees in the wild makes it necessary to better understand their impacts on native populations. We planted 254,400 eggs from 75 families of domesticated, F1-hybrid, and wild salmon in a river containing up- and downstream traps. Additionally, 41,630 hatchery smolts of the same pedigrees were released into the river. Over 8 years, 6,669 out-migrating smolts and 356 returning adults were recaptured and identified to their families of origin with DNA. In comparison with wild salmon, domesticated fish had substantially lower egg to smolt survival (1.8% vs. 3.8% across cohorts), they migrated earlier in the year (11.8 days earlier across years), but they only displayed marginally larger smolt sizes and marginally lower smolt ages. Upon return to freshwater, domesticated salmon were substantially larger at age than wild salmon (2.4 vs. 2.0, 4.8 vs. 3.2, and 8.5 vs. 5.6 kg across sexes for 1, 2, and 3 sea-winter fish) and displayed substantially lower released smolt to adult survival (0.41% vs. 0.94% across releases). Overall, egg-to-returning adult survival ratios were 1:0.76:0.30 and 1:0.44:0.21 for wild:F1-hybrid:domesticated salmon, respectively, using two different types of data. This study represents the most updated and extensive analysis of domesticated, hybrid, and wild salmon in the wild and provides the first documentation of a clear genetic difference in the timing of smolt migration-an adaptive trait presumed to be linked with optimal timing of entry to seawater. We conclude that spawning and hybridization of domesticated escapees can lead to (i) reduced wild smolt output and therefore wild adult abundance, through resource competition in freshwater, (ii) reduced total adult abundance due to freshwater competition and reduced marine survival of domesticated salmon, and (iii) maladaptive changes in phenotypic traits.
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Affiliation(s)
| | | | - Reidar Borgstrøm
- Faculty of Environmental Sciences and Natural Resource ManagementÅsNorway
| | | | | | | | | | - Michael Møller Hansen
- Institute of Marine ResearchNordnes, BergenNorway
- Department of BioscienceAarhus UniversityAarhus CDenmark
| | - Kevin Alan Glover
- Institute of Marine ResearchNordnes, BergenNorway
- Department of Biological SciencesUniversity of BergenBergenNorway
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27
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Ayllon F, Solberg MF, Glover KA, Mohammadi F, Kjærner-Semb E, Fjelldal PG, Andersson E, Hansen T, Edvardsen RB, Wargelius A. The influence of vgll3 genotypes on sea age at maturity is altered in farmed mowi strain Atlantic salmon. BMC Genet 2019; 20:44. [PMID: 31060499 PMCID: PMC6501413 DOI: 10.1186/s12863-019-0745-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/25/2019] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND In Atlantic salmon in the wild, age at maturity is strongly influenced by the vgll3 locus. Under farming conditions, light, temperature and feeding regimes are known significantly advance or delay age at maturity. However, the potential influence of the vgll3 locus on the maturation of salmon reared under farming conditions has been rarely investigated, especially in females. RESULTS Here, we reared domesticated salmon (mowi strain) with different vgll3 genotypes under standard farming conditions until they matured at either one, two or more than two sea winters. Interestingly, and in contrast to previous findings in the wild, we were not able to identify a link between vgll3 and age at maturity in females when reared under farming conditions. For males however, we found that the probability of delaying maturation from one to two sea winters was significantly lower in fish homozygous for the early allele compared to homozygous fish for the late allele, while the probability for heterozygous fish was intermediate. These data also contrast to previous findings in the wild where the early allele has been reported as dominant. However, we found that the probability of males delaying maturation from two to three sea winters was regulated in the same manner as the wild. CONCLUSIONS Collectively, our data suggest that increased growth rates in mowi salmon, caused by high feed intake and artificial light and temperature regimes together with other possible genetic/epigenetic components, may significantly influence the impact that the vgll3 locus has on age at maturity, especially in females. In turn, our results show that the vgll3 locus can only to a large extent be used in selective breeding to control age at maturation in mowi males. In summary, we here show that in contrast to the situation in wild salmon, under farming conditions vgll3 does not seem to influence age at maturity in mowi females whereas in mowi males, maturing as one or two sea winters it alters the early allele effect from dominant to intermediate.
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Affiliation(s)
- Fernando Ayllon
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Monica F Solberg
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kevin A Glover
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Institute of Biology, University of Bergen, Bergen, Norway
| | - Faezeh Mohammadi
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Erik Kjærner-Semb
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Per Gunnar Fjelldal
- Institute of Marine research (IMR), Matre Aquaculture Research Station, 5984, Matredal, Norway
| | - Eva Andersson
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Tom Hansen
- Institute of Marine research (IMR), Matre Aquaculture Research Station, 5984, Matredal, Norway
| | - Rolf B Edvardsen
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.
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28
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Perry WB, Solberg MF, Besnier F, Dyrhovden L, Matre IH, Fjelldal PG, Ayllon F, Creer S, Llewellyn M, Taylor MI, Carvalho G, Glover KA. Evolutionary drivers of kype size in Atlantic salmon ( Salmo salar): domestication, age and genetics. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190021. [PMID: 31183145 PMCID: PMC6502380 DOI: 10.1098/rsos.190021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 03/20/2019] [Indexed: 06/09/2023]
Abstract
The diversity of reproduction and associated mating patterns in Atlantic salmon (Salmo salar) has long captivated evolutionary biologists. Salmo salar exhibit strategies involving migration, bold mating behaviours and radical morphological and physiological change. One such radical change is the elongation and curvature of the lower jaw in sexually mature males into a hook-like appendage called the kype. The kype is a secondary sexual characteristic used in mating hierarchies and a prime candidate for sexual selection. As one of the core global aquaculture fish species, however, mate choice, and thus sexual selection, has been replaced by industrial artificial fertilization seeking to develop more commercially viable strains. Removal of mate choice provides a unique opportunity to examine the kype over successive generations in the absence of sexual selection. Here we use a large-scale common-garden experiment, incorporating six experimental strains (wild, farmed and wild × farmed hybrids), experiencing one to three sea winters, to assess the impact of age and genetic background. After controlling for allometry, fork length-adjusted kype height (AKH) was significantly reduced in the domesticated strain in comparison to two wild strains. Furthermore, genetic variation at a locus on linkage group SSA1 was associated with kype height, and a locus on linkage group SSA23 was associated with fork length-adjusted kype length (AKL). The reduction in fork length-AKH in domesticated salmon suggests that the kype is of importance in mate choice and that it has decreased due to relaxation of sexual selection. Fork length-AKL showed an increase in domesticated individuals, highlighting that it may not be an important cue in mate choice. These results give us insight into the evolutionary significance of the kype, as well as implications of genetic induced phenotypic change caused by domesticated individuals escaping into the natural environment.
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Affiliation(s)
- William Bernard Perry
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Monica Favnebøe Solberg
- Population Genetics Research Group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817 Bergen, Norway
| | - Francois Besnier
- Population Genetics Research Group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817 Bergen, Norway
| | - Lise Dyrhovden
- Matre Research Station, Institute of Marine Research, Matredal, Norway
| | - Ivar Helge Matre
- Matre Research Station, Institute of Marine Research, Matredal, Norway
| | - Per Gunnar Fjelldal
- Population Genetics Research Group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817 Bergen, Norway
| | - Fernando Ayllon
- Population Genetics Research Group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817 Bergen, Norway
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Martin Llewellyn
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Martin I. Taylor
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Gary Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK
| | - Kevin Alan Glover
- Population Genetics Research Group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817 Bergen, Norway
- Institute of Biology, University of Bergen, N-5020 Bergen, Norway
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29
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Sylvester EVA, Wringe BF, Duffy SJ, Hamilton LC, Fleming IA, Castellani M, Bentzen P, Bradbury IR. Estimating the relative fitness of escaped farmed salmon offspring in the wild and modelling the consequences of invasion for wild populations. Evol Appl 2019; 12:705-717. [PMID: 30976304 PMCID: PMC6439497 DOI: 10.1111/eva.12746] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/09/2018] [Accepted: 11/14/2018] [Indexed: 12/25/2022] Open
Abstract
Throughout their native range, wild Atlantic salmon populations are threatened by hybridization and introgression with escapees from net-pen salmon aquaculture. Although domestic-wild hybrid offspring have shown reduced fitness in laboratory and field experiments, consequential impacts on population abundance and genetic integrity remain difficult to predict in the field, in part because the strength of selection against domestic offspring is often unknown and context-dependent. Here, we follow a single large escape event of farmed Atlantic salmon in southern Newfoundland and monitor changes in the in-river proportions of hybrids and feral individuals over time using genetically based hybrid identification. Over a three-year period following the escape, the overall proportion of wild parr increased consistently (total wild proportion of 71.6%, 75.1% and 87.5% each year, respectively), with subsequent declines in feral (genetically pure farmed individuals originating from escaped, farmed adults) and hybrid parr. We quantify the strength of selection against parr of aquaculture ancestry and explore the genetic and demographic consequences for populations in the region. Within-cohort changes in the relative proportions of feral and F1 parr suggest reduced relative survival compared to wild individuals over the first (0.15 and 0.81 for feral and F1, respectively) and second years of life (0.26, 0.83). These relative survivorship estimates were used to inform an individual-based salmon eco-genetic model to project changes in adult abundance and overall allele frequency across three invasion scenarios ranging from short-term to long-term invasion and three relative survival scenarios. Modelling results indicate that total population abundance and time to recovery were greatly affected by relative survivorship and predict significant declines in wild population abundance under continued large escape events and calculated survivorship. Overall, this work demonstrates the importance of estimating the strength of selection against domestic offspring in the wild to predict the long-term impact of farmed salmon escape events on wild populations.
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Affiliation(s)
- Emma V. A. Sylvester
- Science Branch, Fisheries and Oceans CanadaSt. John’sNewfoundland and LabradorCanada
| | - Brendan F. Wringe
- Science Branch, Department of Fisheries and Oceans CanadaBedford Institute of OceanographyDartmouthNova ScotiaCanada
| | - Steven J. Duffy
- Science Branch, Fisheries and Oceans CanadaSt. John’sNewfoundland and LabradorCanada
| | - Lorraine C. Hamilton
- Aquatic Biotechnology Laboratory, Fisheries and Oceans CanadaBedford Institute of OceanographyDartmouthNova ScotiaCanada
| | - Ian A. Fleming
- Memorial University of NewfoundlandDepartment of Ocean SciencesSt. John’sNewfoundland and LabradorCanada
| | - Marco Castellani
- Department of Mechanical EngineeringUniversity of BirminghamBirminghamUK
| | - Paul Bentzen
- Marine Gene Probe Laboratory, Department of BiologyDalhousie UniversityHalifaxNova ScotiaCanada
| | - Ian R. Bradbury
- Science Branch, Fisheries and Oceans CanadaSt. John’sNewfoundland and LabradorCanada
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30
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Andersen Ø, Vieira V, Dessen JE, Johnston IA. Influence of feed ration size on somatic and muscle growth in landlocked dwarf and farmed Atlantic salmon Salmo salar. JOURNAL OF FISH BIOLOGY 2019; 94:614-620. [PMID: 30810225 DOI: 10.1111/jfb.13942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
We examined the possible adaptation of the dwarf Bleke population of Atlantic salmon Salmo salar from Lake Byglandsfjord in southern Norway to limited food resources. The growth performance and muscle development in juvenile Bleke and farmed S. salar under satiated or restricted (50%) feeding were examined for 10 months, starting 3 weeks after first-feeding stage. Four-thousand fish were divided into four replicated groups and random samples of 16-40 fish per group were measured six times during the experiment. The two strains showed no significant difference in mean body mass when fed restricted ration, but the individual variation was considerably higher in the farmed fish. Both Bleke and farmed S. salar grew significantly faster when fed to satiation, but the farmed S. salar showed much higher gain in mass and were three times heavier (201.5 g vs 66.7 g) and possessed twice as many fast muscle fibres (179,682 vs 84,779) compared with landlocked S. salar after 10 months. Farmed fish fed full ration displayed both hypertrophic and hyperplasic muscle growth, while the increased growth in Bleke S. salar was entirely associated with a larger fibre diameter. The landlocked Bleke strain has apparently adapted to low food availability by minimising the metabolic costs of maintenance and growth through reduced dominance hierarchies and by an increase in average muscle fibre diameter relative to the ancestral condition.
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Affiliation(s)
- Øivind Andersen
- Norwegian Institute of Food, Fisheries and Aquaculture Research (Nofima AS), Aas, Norway
- Department of Animal and Aquaculture Sciences, Norwegian University of Life Sciences, Aas, Norway
| | - Vera Vieira
- Gatty Marine Laboratory, School of Biology, University of St Andrews, St Andrews, Scotland, UK
| | - Jens-Erik Dessen
- Norwegian Institute of Food, Fisheries and Aquaculture Research (Nofima AS), Aas, Norway
| | - Ian A Johnston
- Gatty Marine Laboratory, School of Biology, University of St Andrews, St Andrews, Scotland, UK
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31
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Kitada S, Nakajima K, Hamasaki K, Shishidou H, Waples RS, Kishino H. Rigorous monitoring of a large-scale marine stock enhancement program demonstrates the need for comprehensive management of fisheries and nursery habitat. Sci Rep 2019; 9:5290. [PMID: 30918306 PMCID: PMC6437203 DOI: 10.1038/s41598-019-39050-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 01/16/2019] [Indexed: 12/16/2022] Open
Abstract
Release of captively-bred individuals into the wild is one of the most popular tools in fisheries, forestry, and wildlife management, and introgression of hatchery-reared animals into wild populations is of global concern. However, research and monitoring of impacts on wild populations are generally lacking, and the benefit of hatcheries for long-term fisheries and conservation goals is unclear. Using spatio-temporal genetic monitoring and a four-dacade time series of catch data, we quantified the effects on the size and genetic diversity of wild populations of one of the world’s largest marine stock enhancement programs–the red sea bream (Pagrus major) in Kagoshima Bay, Japan. Our analyses found that the stock enhancement program reduced genetic diversity of the population, but the genetic effect diminished with increased size of the wild population. Increases to the seaweed communities and reduced fishing efforts were the primary factors associated with the wild population recovery; effects of aquaculture were much smaller. Our results represent crucial evidence that hatcheries for enhancement and conservation of populations cannot be successful over the long term unless sufficient efforts are also made to reduce harvest rates and rehabilitate natural habitats.
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Affiliation(s)
- Shuichi Kitada
- Tokyo University of Marine Science and Technology, Tokyo, 108-8477, Japan.
| | - Kaori Nakajima
- Tokyo University of Marine Science and Technology, Tokyo, 108-8477, Japan
| | - Katsuyuki Hamasaki
- Tokyo University of Marine Science and Technology, Tokyo, 108-8477, Japan
| | - Hirotoshi Shishidou
- Kagoshima Prefectural Fisheries Technology and Development Center, Kagoshima, 891-0315, Japan
| | - Robin S Waples
- Northwest Fisheries Science Center, NOAA, Seattle, WA, 98112, USA
| | - Hirohisa Kishino
- Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan
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32
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Hagen IJ, Jensen AJ, Bolstad GH, Diserud OH, Hindar K, Lo H, Karlsson S. Supplementary stocking selects for domesticated genotypes. Nat Commun 2019; 10:199. [PMID: 30643117 PMCID: PMC6331577 DOI: 10.1038/s41467-018-08021-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 12/13/2018] [Indexed: 01/21/2023] Open
Abstract
Stocking of hatchery produced fish is common practise to mitigate declines in natural populations and may have unwanted genetic consequences. Here we describe a novel phenomenon arising where broodstock used for stocking may be introgressed with farmed individuals. We test how stocking affects introgression in a wild population of Atlantic salmon (Salmo salar) by quantifying how the number of adult offspring recaptured in a stocked river depend on parental introgression. We found that hatchery conditions favour farmed genotypes such that introgressed broodstock produce up to four times the number of adult offspring compared to non-introgressed broodstock, leading to increased introgression in the recipient spawning population. Our results provide the first empirical evidence that stocking can unintentionally favour introgressed individuals and through selection for domesticated genotypes compromise the fitness of stocked wild populations.
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Affiliation(s)
- Ingerid J Hagen
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, 7485, Trondheim, Norway.
| | - Arne J Jensen
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, 7485, Trondheim, Norway
| | - Geir H Bolstad
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, 7485, Trondheim, Norway
| | - Ola H Diserud
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, 7485, Trondheim, Norway
| | - Kjetil Hindar
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, 7485, Trondheim, Norway
| | - Håvard Lo
- Norwegian Veterinary Institute, P.O. Box 5695 Torgarden, 7485, Trondheim, Norway
| | - Sten Karlsson
- Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, 7485, Trondheim, Norway
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Robertsen G, Reid D, Einum S, Aronsen T, Fleming IA, Sundt‐Hansen LE, Karlsson S, Kvingedal E, Ugedal O, Hindar K. Can variation in standard metabolic rate explain context-dependent performance of farmed Atlantic salmon offspring? Ecol Evol 2019; 9:212-222. [PMID: 30680108 PMCID: PMC6342125 DOI: 10.1002/ece3.4716] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 01/13/2023] Open
Abstract
Escaped farmed Atlantic salmon interbreed with wild Atlantic salmon, leaving offspring that often have lower success in nature than pure wild salmon. On top of this, presence of farmed salmon descendants can impair production of wild-type recruits. We hypothesize that both these effects connect with farmed salmon having acquired higher standard metabolic rates (SMR, the energetic cost of self-maintenance) during domestication. Fitness-related advantages of phenotypic traits associated with both high SMR and farmed salmon (e.g., social dominance) depend on environmental conditions, such as food availability. We hypothesize that farmed offspring have an advantage at high food availability due to, for example, dominance behavior but suffer increased risks of starvation when food is scarce because this behavior is energy-demanding. To test these hypotheses, we first compare embryo SMR of pure farmed, farmed-wild hybrids and pure wild offspring. Next, we test early-life performance (in terms of survival and growth) of hybrids relative to that of their wild half-siblings, as well as their competitive abilities, in semi-natural conditions of high and low food availability. Finally, we test how SMR affects early-life performance at high and low food availability. We find inconclusive support for the hypothesis that domestication has induced increased SMR. Further, wild and hybrid juveniles had similar survival and growth in the semi-natural streams. Yet, the presence of hybrids led to decreased survival of their wild half-siblings. Contrary to our hypothesis about context-dependency, these effects were not modified by food availability. However, wild juveniles with high SMR had decreased survival when food was scarce, but there was no such effect at high food availability. This study provides further proof that farmed salmon introgression may compromise the viability of wild salmon populations. We cannot, however, conclude that this is connected to alterations in the metabolic phenotype of farmed salmon.
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Affiliation(s)
| | - Donald Reid
- School of Life Sciences, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Sigurd Einum
- Centre for Biodiversity Dynamics, Department of BiologyNorwegian University of Science and TechnologyTrondheimNorway
| | - Tonje Aronsen
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Ian A. Fleming
- Department of Ocean SciencesMemorial University of NewfoundlandSt John’sNewfoundlandCanada
| | | | - Sten Karlsson
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Eli Kvingedal
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Ola Ugedal
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Kjetil Hindar
- Norwegian Institute for Nature ResearchTrondheimNorway
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Harvey AC, Skilbrei OT, Besnier F, Solberg MF, Sørvik AGE, Glover KA. Implications for introgression: has selection for fast growth altered the size threshold for precocious male maturation in domesticated Atlantic salmon? BMC Evol Biol 2018; 18:188. [PMID: 30558529 PMCID: PMC6298023 DOI: 10.1186/s12862-018-1294-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 11/16/2018] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Mature male parr (MMP) represent an important alternative life-history strategy in Atlantic salmon populations. Previous studies indicate that the maturation size threshold for male parr varies among wild populations and is influenced by individual growth, environmental conditions, and genetics. More than ten generations of breeding have resulted in domesticated salmon displaying many genetic differences to wild salmon, including greatly increased growth rates. This may have resulted in domesticated fish with the potential to outgrow the size threshold for early maturation, or evolution of the size threshold of the trait itself. To investigate this, we performed a common-garden experiment under farming conditions using 4680 salmon from 39 families representing four wild, two wild-domesticated hybrid, and two domesticated strains. RESULTS Domesticated salmon outgrew wild salmon 2-5-fold, and hybrids displayed intermediate growth. Overall, the numbers of MMP varied greatly among families and strains: averaging 4-12% in domesticated, 18-25% in hybrid, and 43-74% in the wild populations. However, when the influence of growth was accounted for, by dividing fish into lower and upper size modes, no difference in the incidence of MMP was detected among domesticated and wild strains in either size mode. In the lower size mode, hybrids displayed significantly lower incidences of mature males than their wild parental strains. No consistent differences in the body size of MMP, connected to domestication, was detected. CONCLUSIONS Our data demonstrate: 1- no evidence for the evolution of the size threshold for MMP in domesticated salmon, 2- the vastly lower incidence of MMP in domesticated strains under aquaculture conditions is primarily due to their genetically increased growth rate causing them to outgrow the size threshold for early maturation, 3- the incidence of MMP is likely to overlap among domesticated and wild salmon in the natural habitat where they typically display overlapping growth, although hybrid offspring may display lower incidences of mature male parr. These results have implications for wild salmon populations that are exposed to introgression from domesticated escapees.
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Affiliation(s)
- A C Harvey
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway.
| | - O T Skilbrei
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - F Besnier
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - M F Solberg
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - A-G E Sørvik
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - K A Glover
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Department of Biology, University of Bergen, P. O. Box 7803, N-5020, Bergen, Norway
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Glover KA, Solberg MF, Besnier F, Skaala Ø. Cryptic introgression: evidence that selection and plasticity mask the full phenotypic potential of domesticated Atlantic salmon in the wild. Sci Rep 2018; 8:13966. [PMID: 30228303 PMCID: PMC6143624 DOI: 10.1038/s41598-018-32467-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 09/03/2018] [Indexed: 01/13/2023] Open
Abstract
Domesticated Atlantic salmon grow much faster than wild salmon when reared together in fish tanks under farming conditions (size ratios typically 1:2-3). In contrast, domesticated salmon only display marginally higher growth than wild salmon when reared together in rivers (size ratios typically 1:1-1.2). This begs the question why? Is this a difference in the plastic response driven by divergent energy budgets between the two environments, or is it a result of selection, whereby domesticated salmon that display the greatest growth-potential are those at greatest risk of mortality in the wild? We reared domesticated, hybrid and wild salmon in a river until they smoltified at age 2 or 4, and thereafter in fish tanks for a further 2 years. In the river, there was no difference in the mean size between the groups. In contrast, after being transferred from the river to fish tanks, the domesticated salmon significantly outgrew the wild salmon (maximum size ratio of ~1:1.8). This demonstrates that selection alone cannot be responsible for the lack of growth differences observed between domesticated and wild salmon in rivers. Nevertheless, the final size ratios observed after rearing in tanks were lower than expected in that environment, thus suggesting that plasticity, as for selection, cannot be the sole mechanism. We therefore conclude that a combination of energy-budget plasticity, and selection via growth-potential mortality, cause the differences in growth reaction norms between domesticated and wild salmon across these contrasting environments. Our results imply that if phenotypic changes are not observed in wild populations following introgression of domesticated conspecifics, it does not mean that functional genetic changes have not occurred in the admixed population. Clearly, under the right environmental conditions, the underlying genetic changes will manifest themselves in the phenotype.
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Affiliation(s)
- Kevin A Glover
- Institute of Marine Research, P.O. Box 1870, N-5817, Bergen, Norway. .,University of Bergen, Department of Biology, P.O. Box 7803, N-5020, Bergen, Norway.
| | - Monica F Solberg
- Institute of Marine Research, P.O. Box 1870, N-5817, Bergen, Norway
| | - Francois Besnier
- Institute of Marine Research, P.O. Box 1870, N-5817, Bergen, Norway
| | - Øystein Skaala
- Institute of Marine Research, P.O. Box 1870, N-5817, Bergen, Norway
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36
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Wringe BF, Jeffery NW, Stanley RRE, Hamilton LC, Anderson EC, Fleming IA, Grant C, Dempson JB, Veinott G, Duffy SJ, Bradbury IR. Extensive hybridization following a large escape of domesticated Atlantic salmon in the Northwest Atlantic. Commun Biol 2018; 1:108. [PMID: 30271988 PMCID: PMC6123692 DOI: 10.1038/s42003-018-0112-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 07/16/2018] [Indexed: 11/09/2022] Open
Abstract
Domestication is rife with episodes of interbreeding between cultured and wild populations, potentially challenging adaptive variation in the wild. In Atlantic salmon, Salmo salar, the number of domesticated individuals far exceeds wild individuals, and escape events occur regularly, yet evidence of the magnitude and geographic scale of interbreeding resulting from individual escape events is lacking. We screened juvenile Atlantic salmon using 95 single nucleotide polymorphisms following a single, large aquaculture escape in the Northwest Atlantic and report the landscape-scale detection of hybrid and feral salmon (27.1%, 17/18 rivers). Hybrids were reproductively viable, and observed at higher frequency in smaller wild populations. Repeated annual sampling of this cohort revealed decreases in the presence of hybrid and feral offspring over time. These results link previous observations of escaped salmon in rivers with reports of population genetic change, and demonstrate the potential negative consequences of escapes from net-pen aquaculture on wild populations.
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Affiliation(s)
- Brendan F Wringe
- Science Branch, Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, Newfoundland, A1C 5X1, Canada
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland, A1C 5S7, Canada
| | - Nicholas W Jeffery
- Science Branch, Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, Newfoundland, A1C 5X1, Canada
- Faculty of Computer Science, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Ryan R E Stanley
- Science Branch, Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, NS, B2Y 4A2, Canada
| | - Lorraine C Hamilton
- Aquatic Biotechnology Laboratory, Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, NS, B2Y 4A2, Canada
| | - Eric C Anderson
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, 95060, USA
| | - Ian A Fleming
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland, A1C 5S7, Canada
| | - Carole Grant
- Science Branch, Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, Newfoundland, A1C 5X1, Canada
| | - J Brian Dempson
- Science Branch, Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, Newfoundland, A1C 5X1, Canada
| | - Geoff Veinott
- Science Branch, Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, Newfoundland, A1C 5X1, Canada
| | - Steven J Duffy
- Science Branch, Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, Newfoundland, A1C 5X1, Canada
| | - Ian R Bradbury
- Science Branch, Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, Newfoundland, A1C 5X1, Canada.
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland, A1C 5S7, Canada.
- Faculty of Computer Science, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
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Castellani M, Heino M, Gilbey J, Araki H, Svåsand T, Glover KA. Modeling fitness changes in wild Atlantic salmon populations faced by spawning intrusion of domesticated escapees. Evol Appl 2018; 11:1010-1025. [PMID: 29928306 PMCID: PMC5999203 DOI: 10.1111/eva.12615] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 02/11/2018] [Indexed: 12/17/2022] Open
Abstract
Genetic interaction between domesticated escapees and wild conspecifics represents a persistent challenge to an environmentally sustainable Atlantic salmon aquaculture industry. We used a recently developed eco-genetic model (IBSEM) to investigate potential changes in a wild salmon population subject to spawning intrusion from domesticated escapees. At low intrusion levels (5%-10% escapees), phenotypic and demographic characteristics of the recipient wild population only displayed weak changes over 50 years and only at high intrusion levels (30%-50% escapees) were clear changes visible in this period. Our modeling also revealed that genetic changes in phenotypic and demographic characteristics were greater in situations where strayers originating from a neighboring wild population were domestication-admixed and changed in parallel with the focal wild population, as opposed to nonadmixed. While recovery in the phenotypic and demographic characteristics was observed in many instances after domesticated salmon intrusion was halted, in the most extreme intrusion scenario, the population went extinct. Based upon results from these simulations, together with existing knowledge, we suggest that a combination of reduced spawning success of domesticated escapees, natural selection purging maladapted phenotypes/genotypes from the wild population, and phenotypic plasticity, buffer the rate and magnitude of change in phenotypic and demographic characteristics of wild populations subject to spawning intrusion of domesticated escapees. The results of our simulations also suggest that under specific conditions, natural straying among wild populations may buffer genetic changes in phenotypic and demographic characteristics resulting from introgression of domesticated escapees and that variation in straying in time and space may contribute to observed differences in domestication-driven introgression among native populations.
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Affiliation(s)
| | - Mikko Heino
- Department of Biological SciencesUniversity of BergenBergenNorway
- Institute of Marine ResearchBergenNorway
- International Institute for Applied Systems Analysis (IIASA)LaxenburgAustria
| | - John Gilbey
- Freshwater Fisheries LaboratoryMarine ScotlandPitlochryUK
| | - Hitoshi Araki
- Research Faculty of AgricultureHokkaido UniversitySapporoJapan
| | | | - Kevin A. Glover
- Department of Biological SciencesUniversity of BergenBergenNorway
- Institute of Marine ResearchBergenNorway
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Association between sea lice (Lepeophtheirus salmonis) infestation on Atlantic salmon farms and wild Pacific salmon in Muchalat Inlet, Canada. Sci Rep 2018; 8:4023. [PMID: 29507330 PMCID: PMC5838213 DOI: 10.1038/s41598-018-22458-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 02/22/2018] [Indexed: 11/16/2022] Open
Abstract
Growth in salmon aquaculture over the past two decades has raised concerns regarding the potential impacts of the industry on neighboring ecosystems and wild fish productivity. Despite limited evidence, sea lice have been identified as a major cause for the decline in some wild Pacific salmon populations on the west coast of Canada. We used sea lice count and management data from farmed and wild salmon, collected over 10 years (2007–2016) in the Muchalat Inlet region of Canada, to evaluate the association between sea lice recorded on salmon farms with the infestation levels on wild out-migrating Chum salmon. Our analyses indicated a significant positive association between the sea lice abundance on farms and the likelihood that wild fish would be infested. However, increased abundance of lice on farms was not significantly associated with the levels of infestation observed on the wild salmon. Our results suggest that Atlantic salmon farms may be an important source for the introduction of sea lice to wild Pacific salmon populations, but that the absence of a dose response relationship indicates that any estimate of farm impact requires more careful evaluation of causal inference than is typically seen in the extant scientific literature.
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39
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Caldeira C, García-Molina A, Valverde A, Bompart D, Hassane M, Martin P, Soler C. Comparison of sperm motility subpopulation structure among wild anadromous and farmed male Atlantic salmon (Salmo salar) parr using a CASA system. Reprod Fertil Dev 2018; 30:897-906. [DOI: 10.1071/rd17466] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/17/2018] [Indexed: 11/23/2022] Open
Abstract
Atlantic salmon (Salmo salar) is an endangered freshwater species that needs help to recover its wild stocks. However, the priority in aquaculture is to obtain successful fertilisation and genetic variability to secure the revival of the species. The aims of the present work were to study sperm subpopulation structure and motility patterns in wild anadromous males and farmed male Atlantic salmon parr. Salmon sperm samples were collected from wild anadromous salmon (WS) and two generations of farmed parr males. Sperm samples were collected from sexually mature males and sperm motility was analysed at different times after activation (5 and 35 s). Differences among the three groups were analysed using statistical techniques based on Cluster analysis the Bayesian method. Atlantic salmon were found to have three sperm subpopulations, and the spermatozoa in ejaculates of mature farmed parr males had a higher velocity and larger size than those of WS males. This could be an adaptation to high sperm competition because salmonid species are naturally adapted to this process. Motility analysis enables us to identify sperm subpopulations, and it may be useful to correlate these sperm subpopulations with fertilisation ability to test whether faster-swimming spermatozoa have a higher probability of success.
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40
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Crossin GT, Devlin RH. Predation, metabolic priming and early life-history rearing environment affect the swimming capabilities of growth hormone transgenic rainbow trout. Biol Lett 2017; 13:rsbl.2017.0279. [PMID: 28855413 DOI: 10.1098/rsbl.2017.0279] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 08/08/2017] [Indexed: 11/12/2022] Open
Abstract
The period of first feeding, when young salmonid fishes emerge from natal stream beds, is one fraught with predation risk. Experiments conducted in semi-natural stream mesocosms have shown that growth hormone transgenic salmonids are at greater risk of predation than their non-transgenic siblings, due partly to the higher metabolic demands associated with transgenesis, which force risky foraging behaviours. This raises questions as to whether there are differences in the swim-performance of transgenic and non-transgenic fishes surviving predation experiments. We tested this hypothesis in wild-origin rainbow trout (Oncorhynchus mykiss) that were reared from first feeding in semi-natural stream mesocosms characterized by complex hydrodynamics, the presence of predators and oligotrophic conditions. Using an open-flume raceway, we swam fish and measured their capacity for burst-swimming against a sustained flow. We found a significant genotype effect on burst-performance, with transgenic fish sustaining performance longer than their wild-type siblings, both in predator and predator-free stream segments. Importantly, this effect occurred before differences in growth were discernable. We also found that mesocosm-reared fish had greater burst-performance than fish reared in the controlled hatchery environment, despite the latter being unexposed to predators and having abundant food. Our results suggest a potential interaction between predation and metabolic priming, which leads to greater burst capacity in transgenic trout.
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Affiliation(s)
- Glenn T Crossin
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Robert H Devlin
- Fisheries and Oceans Canada, West Vancouver Laboratory, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, British Columbia, Canada V7 V 1N6
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41
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Tufto J. Domestication and fitness in the wild: A multivariate view. Evolution 2017; 71:2262-2270. [DOI: 10.1111/evo.13307] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/30/2017] [Accepted: 07/01/2017] [Indexed: 01/27/2023]
Affiliation(s)
- Jarle Tufto
- Centre for Biodiversity Dynamics/Department of Mathematical Sciences; Norwegian University of Science and Technology; 7491 Trondheim Norway
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42
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Jonsson B, Jonsson M, Jonsson N. Influences of migration phenology on survival are size-dependent in juvenile Atlantic salmon (Salmo salar). CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0136] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Long-distance migratory species can reduce mortality risks by synchronizing the migration event and create confusion by swamping predators with high densities. To reduce confusion, predators are known to primarily select aberrant prey. We hypothesized that at the start of their sea sojourn, particularly small and large Atlantic salmon (Salmo salar L., 1758) would spread the risk by also migrating at other times of the year. Based on data from the Norwegian river Imsa between 1976 and 2015, we found that juveniles, 14–19 cm in total length, started their sea sojourn during a short period between late April and early June. However, more than 20% of fish 13 cm or shorter migrated downstream between October and March, whereas 55% of fish 20 cm or longer migrated downstream between July and September. The regular-sized, spring-migrating juveniles had 2–3 times higher survival at sea than similar-sized conspecifics migrating to sea at other times of the year. The survival at sea for smaller juveniles was not improved by migration in spring relative to winter, and the survival of the largest juveniles was similar in spring and summer. Thus, the migration phenology appears adapted to survival in a high-risk environment by changing the timing according to their sizes.
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Affiliation(s)
- B. Jonsson
- Norwegian Institute for Nature Research, Gaustadalléen 21, N-0349 Oslo, Norway
| | - M. Jonsson
- Department of Physics, University of Oslo, P.O. Box 1048, Blindern, N-0316 Oslo, Norway
| | - N. Jonsson
- Norwegian Institute for Nature Research, Gaustadalléen 21, N-0349 Oslo, Norway
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Hamoutene D, Perez-Casanova J, Burt K, Lush L, Caines J, Collier C, Hinks R. Early life traits of farm and wild Atlantic salmon Salmo salar and first generation hybrids in the south coast of Newfoundland. JOURNAL OF FISH BIOLOGY 2017; 90:2271-2288. [PMID: 28488356 DOI: 10.1111/jfb.13304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 03/01/2017] [Indexed: 06/07/2023]
Abstract
This study examined fertilization rates, survival and early life-trait differences of pure farm, wild and first generation (F1) hybrid origin embryos after crossing farm and wild Atlantic salmon Salmo salar. Results show that despite a trend towards higher in vitro fertilization success for wild females, differences in fertilization success in river water are not significantly different among crosses. In a hatchery environment, wild females' progeny (pure wild and hybrids with wild maternal parent) hatched 7-11 days earlier than pure farm crosses and hybrids with farm maternal parents. In addition, pure wild progeny had higher total lengths (LT ) at hatch than pure farm crosses and hybrids. Directions in trait differences need to be tested in a river environment, but results clearly show the maternal influence on early stages beyond egg-size differences. Differences in LT were no longer significant at 70 days post hatch (shortly after the onset of exogenous feeding) showing the need to investigate later developmental stages to better assess somatic growth disparities due to genetic differences. Higher mortality rates of the most likely hybrids (farm female × wild male hybrids) at egg and fry stages and their delayed hatch suggest that these F1 hybrids might be less likely to survive the early larval stages than wild stocks.
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Affiliation(s)
- D Hamoutene
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, P. O. Box 5667, St John's, NL, A1C 5X1, Canada
| | - J Perez-Casanova
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, P. O. Box 5667, St John's, NL, A1C 5X1, Canada
| | - K Burt
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, P. O. Box 5667, St John's, NL, A1C 5X1, Canada
| | - L Lush
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, P. O. Box 5667, St John's, NL, A1C 5X1, Canada
| | - J Caines
- Northern Harvest Sea Farms NL Ltd., P. O. Box 190, St Alban's, NL, A0H 2E0, Canada
| | - C Collier
- Gray Aqua Group Limited, P. O. Box 275, Conne River, NL, A0H 1J0, Canada
| | - R Hinks
- Natural Resources Miawpukek First Nations, MiawpukekMi'kamaweyMawi'omi, P. O. Box 10, Conne River, NL, A0H 1J0, Canada
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Lundebye AK, Lock EJ, Rasinger JD, Nøstbakken OJ, Hannisdal R, Karlsbakk E, Wennevik V, Madhun AS, Madsen L, Graff IE, Ørnsrud R. Lower levels of Persistent Organic Pollutants, metals and the marine omega 3-fatty acid DHA in farmed compared to wild Atlantic salmon (Salmo salar). ENVIRONMENTAL RESEARCH 2017; 155:49-59. [PMID: 28189073 DOI: 10.1016/j.envres.2017.01.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/13/2017] [Accepted: 01/23/2017] [Indexed: 05/19/2023]
Abstract
Contaminants and fatty acid levels in farmed- versus wild Atlantic salmon have been a hot topic of debate in terms of food safety. The present study determined dioxins (polychlorinated dibenzo-p-dioxin and dibenzofuran), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), metals and fatty acids in wild and farmed Atlantic salmon. Contaminant levels of dioxins, PCBs, OCPs (DDT, dieldrin, lindane, chlordane, Mirex, and toxaphene), and mercury were higher in wild salmon than in farmed salmon, as were the concentrations of the essential elements selenium, copper, zinc and iron, and the marine omega-3 fatty acid docosahexaenoic acid (DHA). PBDE, endosulfan, pentachlorobenzene, hexachlorobenzene, cadmium and lead levels were low and comparable in both wild and farmed fish, and there was no significant difference in the marine omega-3 fatty acid eicosapentaenoic acid (EPA) concentration. The total fat content was significantly higher in farmed than wild salmon due to a higher content of both saturated and monounsaturated fatty acids, as well as a higher content of omega-6 fatty acids. The omega-3 to omega-6 fatty acid ratio was considerably lower in farmed than wild salmon due to the high level of omega-6 fatty acids. Contaminant concentrations in Atlantic salmon were well below maximum levels applicable in the European Union. Atlantic salmon, both farmed and wild, is a good source of EPA and DHA with a 200g portion per week contributing 3.2g or 2.8g respectively, being almost twice the intake considered adequate for adults by the European Food Safety Authority (i.e. 250mg/day or 1.75g/week).
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Affiliation(s)
- Anne-Katrine Lundebye
- National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes, 5817 Bergen, Norway.
| | - Erik-Jan Lock
- National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes, 5817 Bergen, Norway
| | - Josef D Rasinger
- National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes, 5817 Bergen, Norway
| | - Ole Jakob Nøstbakken
- National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes, 5817 Bergen, Norway
| | - Rita Hannisdal
- National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes, 5817 Bergen, Norway
| | - Egil Karlsbakk
- Institute of Marine Research,, P.O. Box 1870 Nordnes, 5817 Bergen, Norway
| | - Vidar Wennevik
- Institute of Marine Research,, P.O. Box 1870 Nordnes, 5817 Bergen, Norway
| | - Abdullah S Madhun
- Institute of Marine Research,, P.O. Box 1870 Nordnes, 5817 Bergen, Norway
| | - Lise Madsen
- National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes, 5817 Bergen, Norway
| | - Ingvild Eide Graff
- National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes, 5817 Bergen, Norway
| | - Robin Ørnsrud
- National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes, 5817 Bergen, Norway
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Bolstad GH, Hindar K, Robertsen G, Jonsson B, Sægrov H, Diserud OH, Fiske P, Jensen AJ, Urdal K, Næsje TF, Barlaup BT, Florø-Larsen B, Lo H, Niemelä E, Karlsson S. Gene flow from domesticated escapes alters the life history of wild Atlantic salmon. Nat Ecol Evol 2017; 1:124. [PMID: 28812692 DOI: 10.1038/s41559-017-0124] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/23/2017] [Indexed: 11/09/2022]
Abstract
Interbreeding between domesticated and wild animals occurs in several species. This gene flow has long been anticipated to induce genetic changes in life-history traits of wild populations, thereby influencing population dynamics and viability. Here, we show that individuals with high levels of introgression (domesticated ancestry) have altered age and size at maturation in 62 wild Atlantic salmon Salmo salar populations, including seven ancestral populations to breeding lines of the domesticated salmon. This study documents widespread changes to life-history traits in wild animal populations following gene flow from selectively bred, domesticated conspecifics. The continued high abundance of escaped, domesticated Atlantic salmon thus threatens wild Atlantic salmon populations by inducing genetic changes in fitness-related traits. Our results represent key evidence and a timely warning concerning the potential ecological impacts of the globally increasing use of domesticated animals.
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Affiliation(s)
- Geir H Bolstad
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Kjetil Hindar
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Grethe Robertsen
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Bror Jonsson
- Norwegian Institute for Nature Research (NINA), NO-0349 Oslo, Norway
| | | | - Ola H Diserud
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Peder Fiske
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Arne J Jensen
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | - Kurt Urdal
- Radgivende Biologer, NO-5003 Bergen, Norway
| | - Tor F Næsje
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
| | | | | | - Håvard Lo
- Norwegian Veterinary Institute, NO-7485 Trondheim, Norway
| | - Eero Niemelä
- Natural Resources Institute Finland, FI-90014 Oulu, Finland
| | - Sten Karlsson
- Norwegian Institute for Nature Research (NINA), NO-7485 Trondheim, Norway
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46
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The Development of Sustainable Saltwater-Based Food Production Systems: A Review of Established and Novel Concepts. WATER 2016. [DOI: 10.3390/w8120598] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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47
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Harvey AC, Solberg MF, Troianou E, Carvalho GR, Taylor MI, Creer S, Dyrhovden L, Matre IH, Glover KA. Plasticity in growth of farmed and wild Atlantic salmon: is the increased growth rate of farmed salmon caused by evolutionary adaptations to the commercial diet? BMC Evol Biol 2016; 16:264. [PMID: 27905882 PMCID: PMC5134087 DOI: 10.1186/s12862-016-0841-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 11/25/2016] [Indexed: 11/10/2022] Open
Abstract
Background Domestication of Atlantic salmon for commercial aquaculture has resulted in farmed salmon displaying substantially higher growth rates than wild salmon under farming conditions. In contrast, growth differences between farmed and wild salmon are much smaller when compared in the wild. The mechanisms underlying this contrast between environments remain largely unknown. It is possible that farmed salmon have adapted to the high-energy pellets developed specifically for aquaculture, contributing to inflated growth differences when fed on this diet. We studied growth and survival of 15 families of farmed, wild and F1 hybrid salmon fed three contrasting diets under hatchery conditions; a commercial salmon pellet diet, a commercial carp pellet diet, and a mixed natural diet consisting of preserved invertebrates commonly found in Norwegian rivers. Results For all groups, despite equal numbers of calories presented by all diets, overall growth reductions as high 68 and 83%, relative to the salmon diet was observed in the carp and natural diet treatments, respectively. Farmed salmon outgrew hybrid (intermediate) and wild salmon in all treatments. The relative growth difference between wild and farmed fish was highest in the carp diet (1: 2.1), intermediate in the salmon diet (1:1.9) and lowest in the natural diet (1:1.6). However, this trend was non-significant, and all groups displayed similar growth reaction norms and plasticity towards differing diets across the treatments. Conclusions No indication of genetic-based adaptation to the form or nutritional content of commercial salmon diets was detected in the farmed salmon. Therefore, we conclude that diet alone, at least in the absence of other environmental stressors, is not the primary cause for the large contrast in growth differences between farmed and wild salmon in the hatchery and wild. Additionally, we conclude that genetically-increased appetite is likely to be the primary reason why farmed salmon display higher growth rates than wild salmon when fed ad lib rations under hatchery conditions. Our results contribute towards an understanding of the potential genetic changes that have occurred in farmed salmon in response to domestication, and the potential mechanisms underpinning genetic and ecological interactions between farmed escapees and wild salmonids. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0841-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alison Catherine Harvey
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, UK
| | | | - Eva Troianou
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Gary Robert Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, UK
| | - Martin Ian Taylor
- School of Biological Sciences, University of East Anglia, NR4 7TJ, Norwich, UK
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, UK
| | - Lise Dyrhovden
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Ivar Helge Matre
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kevin Alan Glover
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen, Norway
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Harvey AC, Solberg MF, Glover KA, Taylor MI, Creer S, Carvalho GR. Plasticity in response to feed availability: Does feeding regime influence the relative growth performance of domesticated, wild and hybrid Atlantic salmon Salmo salar parr? JOURNAL OF FISH BIOLOGY 2016; 89:1754-1768. [PMID: 27460446 DOI: 10.1111/jfb.13076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/09/2016] [Indexed: 06/06/2023]
Abstract
Growth of farmed, wild and F1 hybrid Atlantic salmon parr Salmo salar was investigated under three contrasting feeding regimes in order to understand how varying levels of food availability affects relative growth. Treatments consisted of standard hatchery feeding (ad libitum), access to feed for 4 h every day, and access to feed for 24 h on three alternate days weekly. Mortality was low in all treatments, and food availability had no effect on survival of all groups. The offspring of farmed S. salar significantly outgrew the wild S. salar, while hybrids displayed intermediate growth. Furthermore, the relative growth differences between the farmed and wild S. salar did not change across feeding treatments, indicating a similar plasticity in response to feed availability. Although undertaken in a hatchery setting, these results suggest that food availability may not be the sole driver behind the observed reduced growth differences found between farmed and wild fishes under natural conditions.
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Affiliation(s)
- A C Harvey
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, U.K
| | - M F Solberg
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - K A Glover
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
- Department of Biology, Sea Lice Research Centre, University of Bergen, P. O. Box 7803, N-5020, Bergen, Norway
| | - M I Taylor
- School of Biological Sciences, University of East Anglia, NR4 7TJ, Norwich, U.K
| | - S Creer
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, U.K
| | - G R Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, U.K
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49
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Harvey AC, Juleff G, Carvalho GR, Taylor MI, Solberg MF, Creer S, Dyrhovden L, Matre IH, Glover KA. Does density influence relative growth performance of farm, wild and F1 hybrid Atlantic salmon in semi-natural and hatchery common garden conditions? ROYAL SOCIETY OPEN SCIENCE 2016; 3:160152. [PMID: 27493772 PMCID: PMC4968464 DOI: 10.1098/rsos.160152] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/27/2016] [Indexed: 06/06/2023]
Abstract
The conditions encountered by Atlantic salmon, Salmo salar L., in aquaculture are markedly different from the natural environment. Typically, farmed salmon experience much higher densities than wild individuals, and may therefore have adapted to living in high densities. Previous studies have demonstrated that farmed salmon typically outgrow wild salmon by large ratios in the hatchery, but these differences are much less pronounced in the wild. Such divergence in growth may be explained partly by the offspring of wild salmon experiencing higher stress and thus lower growth when compared under high-density farming conditions. Here, growth of farmed, wild and F1 hybrid salmon was studied at contrasting densities within a hatchery and semi-natural environment. Farmed salmon significantly outgrew hybrid and wild salmon in all treatments. Importantly, however, the reaction norms were similar across treatments for all groups. Thus, this study was unable to find evidence that the offspring of farmed salmon have adapted more readily to higher fish densities than wild salmon as a result of domestication. It is suggested that the substantially higher growth rate of farmed salmon observed in the hatchery compared with wild individuals may not solely be caused by differences in their ability to grow in high-density hatchery scenarios.
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Affiliation(s)
- Alison C. Harvey
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
| | - Gareth Juleff
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
| | - Gary R. Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
| | - Martin I. Taylor
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
- Biological Sciences, University of East Anglia, Norwich, UK
| | | | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
| | | | | | - Kevin A. Glover
- Havforskningsinstituttet, Bergen, Norway
- Sea Lice Research Centre, Universitetet i Bergen Institutt for Biologi, Bergen, Norway
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50
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Bicskei B, Taggart JB, Glover KA, Bron JE. Comparing the transcriptomes of embryos from domesticated and wild Atlantic salmon (Salmo salar L.) stocks and examining factors that influence heritability of gene expression. Genet Sel Evol 2016; 48:20. [PMID: 26987528 PMCID: PMC4797325 DOI: 10.1186/s12711-016-0200-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 03/07/2016] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Due to selective breeding, domesticated and wild Atlantic salmon are genetically diverged, which raises concerns about farmed escapees having the potential to alter the genetic composition of wild populations and thereby disrupting local adaptation. Documenting transcriptional differences between wild and domesticated stocks under controlled conditions is one way to explore the consequences of domestication and selection. We compared the transcriptomes of wild and domesticated Atlantic salmon embryos, by using a custom 44k oligonucleotide microarray to identify perturbed gene pathways between the two stocks, and to document the inheritance patterns of differentially-expressed genes by examining gene expression in their reciprocal hybrids. RESULTS Data from 24 array interrogations were analysed: four reciprocal cross types (W♀ × W♂, D♀ × W♂; W♀ × D♂, D♀ × D♂) × six biological replicates. A common set of 31,491 features on the microarrays passed quality control, of which about 62 % were assigned a KEGG Orthology number. A total of 6037 distinct genes were identified for gene-set enrichment/pathway analysis. The most highly enriched functional groups that were perturbed between the two stocks were cellular signalling and immune system, ribosome and RNA transport, and focal adhesion and gap junction pathways, relating to cell communication and cell adhesion molecules. Most transcripts that were differentially expressed between the stocks were governed by additive gene interaction (33 to 42 %). Maternal dominance and over-dominance were also prevalent modes of inheritance, with no convincing evidence for a stock effect. CONCLUSIONS Our data indicate that even at this relatively early developmental stage, transcriptional differences exist between the two stocks and affect pathways that are relevant to wild versus domesticated environments. Many of the identified differentially perturbed pathways are involved in organogenesis, which is expected to be an active process at the eyed egg stage. The dominant effects are more largely due to the maternal line than to the origin of the stock. This finding is particularly relevant in the context of potential introgression between farmed and wild fish, since female escapees tend to have a higher spawning success rate compared to males.
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Affiliation(s)
- Beatrix Bicskei
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK.
| | - John B Taggart
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Kevin A Glover
- Institute of Marine Research, Bergen, Norway.,Department of Biology, University of Bergen, Bergen, Norway
| | - James E Bron
- Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
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