Grandparent Inference from Genetic Data: The Potential for Parentage‐Based Tagging Programs to Identify Offspring of Hatchery Strays

Abstract Fisheries managers routinely use hatcheries to increase angling opportunity. Many operate as segregated programs where hatchery‐origin fish are not intended spawn with natural‐origin conspecifics in order prevent potential negative effects on the population. Currently available techniques monitor frequency which strays successfully wild rely either genetic differentiation between hatchery‐ and or extensive sampling of spawning grounds. We present a method infer grandparent–grandchild trios by using only genotypes from two putative grandparents one grandchild. developed estimators false‐positive false‐negative error rates showed that panels containing 500–700 single‐nucleotide polymorphisms 200–300 microhaplotypes expected allow application this technique for monitoring hatchery programs. discuss ease can be implemented pre‐existing parentage‐based tagging provide an R package applies method.