Genetic Stock Identification

Genetic stock identification uses inherited DNA markers to assign individual fish to their population of origin, testing whether management units match true reproductive boundaries. Microsatellites and single-nucleotide polymorphisms (SNPs) build a baseline of allele frequencies for each candidate population, then mixed-stock analysis estimates each population’s share of a mixed-fishery catch. The method resolves stock structure that morphology and tagging miss, separates straddling and shared stocks, and detects mislabeled harvest. RFMOs apply it to tuna and salmon to confirm that the unit stock managed under one quota is a single population, not a blend of distinct breeding groups.