Conservation Genetics

, Volume 2, Issue 3, pp 257–269

Stability in the historical pattern of genetic structure of Newfoundland cod (Gadus morhua) despite the catastrophic decline in population size from 1964 to 1994


    • Danish Institute for Fisheries ResearchDepartment of Inland Fisheries
  • Christopher T. Taggart
    • Department of Oceanography, Marine Gene Probe LaboratoryDalhousie University
  • Roger W. Doyle
    • Department of Biology, Marine Gene Probe LaboratoryDalhousie University
  • Doug Cook
    • Marine Gene Probe LaboratoryDalhousie University

DOI: 10.1023/A:1012247213644

Cite this article as:
Ruzzante, D.E., Taggart, C.T., Doyle, R.W. et al. Conservation Genetics (2001) 2: 257. doi:10.1023/A:1012247213644


We report on evidence of long term stability inthe geographic pattern of geneticdifferentiation among cod (Gadus morhua)collected from 5 spawning banks offNewfoundland and Labrador over a periodspanning three decades (1964–1994) and 2orders of magnitude of population sizevariation. Six microsatellite DNA lociamplified from archived otoliths (1964 and1978) and contemporary (1990s) tissue samplesrevealed fidelity to natal spawning banks overthis period. A two level (spawning bank anddecade) hierarchical and multilocus AMOVAindicated that 1.55% of the total variation inallele frequencies could be attributed(P = 0.036) to spatial structure while novariance component could be attributed totemporal changes. A finer scale analysis amongcod from just 3 of these spawning banksreveals, however, evidence consistent with somepost-collapse mixing between cod from twobanks. In the context of fisheries managementand conservation, the survival of the spatialpattern of genetic differentiation during thepopulation collapse suggests that if recoveryeventually occurs it will likely be throughpopulation re-growth in situ rather thanby migratory influx.

cod (Gadus morhua)fisheries management and conservationhistorical microsatellite DNA from otolithspopulation structurespawning fidelity
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© Kluwer Academic Publishers 2001