Management implications of shifting baselines in fish stock assessments

Abstract

AbstractTo make sound decisions about the future of fisheries, managers need to have a good understanding of the amount of fish that have been caught over long periods. Unfortunately, current stock assessment processes are often flawed, as they are frequently based on data time series that do not represent the full range of change. The process of selecting a shortened (or truncated) time series may lead to misconceptions regarding the fishery's status and impact on management decisions. This study investigates shifting baseline effects in official stock assessments from the Ransom Myers Legacy Stock Assessment Database that used truncated catch time series. The findings suggest that truncated time series often fail to account for important features, such as historical biomass maxima, past recoveries, low abundance levels and biomass fluctuations, whose omission can bias reference points and perceptions of stock status. This study emphasises the importance of considering long‐term data wherever possible to improve historical scientific baselines and inform sustainable fisheries management.