Skip to main content
padlock icon - secure page this page is secure

Population structure, effective population size and adverse effects of stocking in the endangered Australian eastern freshwater cod Maccullochella ikei

Buy Article:

$52.00 + tax (Refund Policy)

Microsatellite markers were used to examine spatio-temporal genetic variation in the endangered eastern freshwater cod Maccullochella ikei in the Clarence River system, eastern Australia. High levels of population structure were detected. A model-based clustering analysis of multilocus genotypes identified four populations that were highly differentiated by F-statistics (FST = 0· 09 − 0· 49; P < 0· 05), suggesting fragmentation and restricted dispersal particularly among upstream sites. Hatchery breeding programmes were used to re-establish locally extirpated populations and to supplement remnant populations. Bayesian and frequency-based analyses of hatchery fingerling samples provided evidence for population admixture in the hatchery, with the majority of parental stock sourced from distinct upstream sites. Comparison between historical and contemporary wild-caught samples showed a significant loss of heterozygosity (21%) and allelic richness (24%) in the Mann and Nymboida Rivers since the commencement of stocking. Fragmentation may have been a causative factor; however, temporal shifts in allele frequencies suggest swamping with hatchery-produced M. ikei has contributed to the genetic decline in the largest wild population. This study demonstrates the importance of using information on genetic variation and population structure in the management of breeding and stocking programmes, particularly for threatened species.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: conservation; genetic variation; isolation by distance; microsatellite; stocking impact

Document Type: Regular Paper

Affiliations: 1: Molecular Fisheries Laboratory, Queensland Department of Employment, Economic Development and Innovation, St Lucia, QLD, Australia 2: Grafton Aquaculture Centre, Industry and Investment NSW, Grafton, NSW, Australia 3: Narrandera Fisheries Centre, Industry and Investment NSW, Narrandera, NSW, Australia 4: Fisheries and Marine Sciences, Australian Bureau of Agricultural and Resource Economics–Bureau of Rural Sciences, Department of Agriculture, Fisheries and Forestry, Canberra, ACT, Australia 5: Centres for Animal and Plant Conservation Genetics, Southern Cross University, P. O. Box 157 Lismore, NSW, Australia

Publication date: January 1, 2011

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more