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Variable stocking effect and endemic population genetic structure in Murray cod Maccullochella peelii
M L Rourke1, H C McPartlan, B A Ingram
1Australian Centre for Biodiversity, School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia. meaghan.rourke@industry.nsw.gov.au
Journal of Fish Biology
|July 5, 2011
Summary
Stocking Murray cod (Maccullochella peelii) in the Murray-Darling Basin shows varied genetic impacts. While some populations remain panmictic, others exhibit distinct genetic changes due to stocking efforts.
Area of Science:
- Fisheries Science
- Conservation Genetics
- Ecology
Background:
- Murray cod (Maccullochella peelii) are a significant freshwater fish in the Murray-Darling Basin (MDB).
- Decades of stocking hatchery-reared fish aim to support wild populations.
- Understanding the genetic consequences of stocking is crucial for effective conservation.
Purpose of the Study:
- To investigate the genetic structure of Murray cod across the MDB.
- To assess the genetic impacts of long-term stocking programs on wild populations.
- To identify specific catchments where stocking has influenced genetic diversity.
Main Methods:
- Utilized microsatellite markers for genetic analysis.
- Employed Bayesian analysis (Structure) to infer population genetic structure.
- Compared genetic profiles of wild populations with stocking records.
Main Results:
- Murray cod populations are largely genetically panmictic throughout most of the MDB, suggesting high connectivity.
- Three distinct populations were identified in the Lachlan, Macquarie, and Gwydir catchments.
- Stocking significantly altered the genetic structure in the Gwydir and Macquarie catchments, but not in the Lachlan.
Conclusions:
- Murray cod stocking has had variable genetic effects across the MDB.
- High connectivity maintains panmixia in many areas, masking stocking impacts.
- Specific catchments show clear genetic changes, highlighting the need for targeted management strategies.
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