A Framework for Conditioning Operating Models for the Southwest Nova Scotia/Bay of Fundy Spawning Component of 4VWX Herring

Abstract

An approach for conditioning operating models is described and demonstrated for use in a management strategy evaluation for the southwest Nova Scotia / Bay of Fundy spawning component of Atlantic Herring in NAFO area 4VWX. This document (1) provides a detailed account of operating model structure and estimation methods; (2) describes a reference case operating model; (3) investigates sensitivities of conditioning to central uncertainties identified for Atlantic Herring; (4) evaluates the impact of these sensitivities to determine a reference set grid of operating models spanning natural mortality rate, growth, resilience, and historical catch levels; (5) identifies those reference set operating models with the most contrasting implications for MSE projection for use in robustness operating models; (6) identifies outstanding sources of uncertainty and specifies robustness operating models that address these uncertainties; (7) references supporting documentation that allow for reproduction of all results. The reference set of operating models spanned a range of current stock status, magnitude of the current stock and the sustainable rate of exploitation. Additionally, 25 robustness operating models were specified that encompassed an additional eight sources of uncertainty in Herring fishery dynamics and can be used to further discriminate among candidate management procedures.