Maintaining a wild phenotype in a conservation hatchery program for Chinook salmon: The effect of managed breeding on early male maturation

Details

• Alternative Title:
  Maintaining a wild phenotype in a conservation hatchery program for Chinook salmon: The effect of managed breeding on early male maturation
• Journal Title:
  PLOS ONE
• Personal Author:
  Larsen, Donald A. ; Harstad, Deborah L. ; Fuhrman, Abby E. ; Knudsen, Curtis M. ; Schroder, Steven L. ; Bosch, William J. ; Galbreath, Peter F. ; Fast, David E. ; Beckman, Brian R.
• NOAA Program & Office:
  NMFS (National Marine Fisheries Service) ; NWFSC (Northwest Fisheries Science Center)
• Description:
  In many salmonid species, age and size at maturation is plastic and influenced by the interaction between genetic and environmental factors. Hatchery reared salmon often mature at an earlier age and smaller size than wild fish. Modern salmon conservation efforts have focused on managing the level of gene flow between hatchery and natural origin fish to minimize potential genotypic and phenotypic change. In salmonids, maturation probability is dependent on exceeding a genetically set threshold in growth rate and energetic status (and by association, body size) referred to as the probabalisitic maturation reaction norm (PMRN). Over fourteen years, we monitored the frequency of age-2 precocious male maturation (common term: age-2 minijack rate) and the PMRN of natural founder (FNDR), integrated natural-hatchery (INT), and segregated hatchery (SEG) broodlines of spring Chinook salmon, Oncorhynchus tshawytscha. The average age-2 minijack rate (+/- SEM) of the FNDR, INT and SEG broodlines was 48.2 +/- 5.2%, 41.9 +/- 3.6% and 30.9 +/- 4.7%, respectively. Additionally, the PMRNWP50 (predicted weight at 50% maturation) of the SEG broodline was significantly greater (20.5 g) than that of the FNDR/INT broodlines (18.2 g). We also conducted a common garden experiment exploring the effects of less than one [INT (0-1)], one [SEG (1)] or two [SEG (2)] generations of hatchery culture on the age-2 minijack rate and PMRNWP50. Growth was not significantly different among broodlines, but age-2 minijack rates were significantly lower following two consecutive generations of hatchery culture: [INT (0-1): 68.3 +/- 1.7%], [SEG (1): 70.3 +/- 1.8%] and [SEG (2): 58.6 +/- 0.4%] and the PMRNWP50 was significantly higher by 6.1 g after two generations of SEG culture. These results indicate that managed gene flow reduces phenotypic divergence, but may serve to maintain potentially undesirably high age-2 minijack rates in salmon conservation hatchery programs.
• Keywords:
  Chinook Salmon Evolution Hatchery Fishes History Life Maturation Reaction Reproduction Salmon Science Technology Variation (Biology) Chinook Salmon Hatchery Fishes

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• Source:
  PLOS ONE, 14(5), 32
• DOI:
  https://doi.org/10.1371/journal.pone.0216168
• Pubmed Central ID:
  PMC6519831
• Document Type:
  Journal Article
• Place as Subject:
  United States ; Yakima River Valley (Wash.)
• Rights Information:
  CC BY
• Compliance:
  PMC
• Main Document Checksum:
  urn:sha-512:39a1227a6478b0a4e4512edcb31cb3c74af801f352c8c79d912d5948b4535f486e8384616e546a18b8ec955a38077b010748292b10b32150e748733ad51584ec
• Download URL:
  https://repository.library.noaa.gov/view/noaa/24453/noaa_24453_DS1.pdf
• File Type:
  [PDF - 3.40 MB ]