A methodology for the initial stock assessment and adaption of catch limits and tagging rates is presented for new and exploratory stocks in the CAMLR Convention Area. The assessment methodology is designed to be able to accommodate mark–recapture data, catch (legal and illegal, unreported and unregulated (IUU)) and relative abundance data into an integrated assessment framework when more detailed data are not available – namely catch-at-length/age data and tagging data at-length/age. A simple algorithm, based upon the Petersen abundance estimator, is defined whereby catch limits and tagging rates can be adjusted together to define tagging levels that will produce an expected abundance estimate in the following year of a given precision whilst ensuring the sustainable exploitation of the stock as per the CCAMLR management procedure. The combination of the assessment and tagging rate adaption methods can then form the basis of an early management plan for exploratory fisheries. The accuracy of the catch limit and tag-rate adaption algorithm is tested using the assessment results for toothfish in CCAMLR Subarea 48.3 and the assessment method is applied to the catch (legal and IUU) and mark–recapture data for Patagonian toothfish (Dissostichus eleginoides) in Division 58.4.3a with catch limit and tag-rate recommendations being made given the assessment results and using the catch limit/tag-rate adaption algorithm.