Alternative Methodologies for Providing Interim Catch Advice for Eastern Georges Bank Cod

Following the 2018 TRAC, poor diagnostics of both the VPA and ASAP assessment models for eastern Georges Bank cod resulted in TMGC requesting that TRAC investigate alternative methodologies for providing catch advice until a benchmark can be held. The two approaches presented for further exploration in this document are the Rose and Data Limited Methods Tool (DLMtool). The Rose approach uses a variety of assessment models to address retrospective patterns and provide catch advice based on the ensemble of models through either a formulaic calculation or making trade-offs between short and long term consequences. The DLMtool provides a simulation platform which mimics stock dynamics across a range of uncertainties, against which simple index-based management procedures for provision of interim advice can be tested. Pros and cons of both approaches will be discussed and a decision will be made regarding which one of the two approaches will be used to provide advice at the 2020 TRAC.