This project developed and simulation tested harvest control rules (HCRs) that do not depend on biological reference points based on unfished biomass, B0, using a close-kin mark-recapture (CKMR) assessment. Instead of unfished biomass, the HCRs evaluated in this project utilise spawning potential ratio (SPR), the ratio of the spawning biomass-per-recruit that is expected to be produced over the lifetime of a cohort with and without fishing. SPR can be calculated from CKMR assessments and, as it does not depend on knowing unfished biomass, it is ideal for situations where B0 is not available. The HCRs were tested on a generic shark-like species, based on School Shark (Galeorhinus galeus) and a generic teleost species, based on Tiger Flathead (Neoplatycephalus richardsoni). This project demonstrates that SPR-based reference points can be applied for CKMR assessments of both sharks and teleosts where B0 is not available. The process for applying the HCRs developed in this project to Australia’s School Shark in the Southern and Eastern Scalefish and Shark Fishery (SESSF) is currently being developed by the Australian Fisheries Management Authority (AFMA) and CSIRO.