Close‑kin mark‑recapture scoping suggests CKMR could reduce uncertainty for some stocks

Erin Jacobson described a Commission‑funded project to evaluate close‑kin mark‑recapture (CKMR) for U.S. marine mammal stocks. CKMR uses genetic identification of close relatives (parents, siblings) to infer population size from samples, and it can incorporate samples from live biopsies, strandings and harvests. Jacobson said the method scales efficiently for very large populations but is less useful for very small stocks because sample requirements increase as population size declines.

Drawing on a published simulation study for Pacific walrus, Jacobson said adding CKMR to existing biopsy programs could reduce uncertainty in abundance estimates by nearly half, shortening intensive field effort. The project's next steps are to score all 258 U.S. marine mammal stocks for CKMR feasibility and necessity, identify three to five priority stocks for CKMR implementation, catalogue existing sample holdings, and build a roadmap for agency collaboration. "The goal here is to survey all of the marine mammal stocks in the U.S. and identify maybe three to five of them that we think could be suitable for CKMR," Jacobson said.