Response to Removing Biases in Forecasts of Fishery Status

U. T. Srinivasan, W. W. L. Cheung, R. Watson, U. R. Sumaila, (2013). Journal of Bioeconomics.

Previously in this journal, we demonstrated an empirical relationship between maximum sustainable yield (MSY) and historical maximum catch (Cmax) for fishery stocks off the Northeast U.S.—a relationship we then applied to estimate the potential catch losses from unsustainable fishing worldwide (Srinivasan et al. 2010). Two studies have since found similar relationships between MSY and maximum catch using larger regional datasets (Froese et al. 2012; Halpern et al. 2012). In a third paper in this issue of the Journal of Bioeconomics, Costello et al. (in press) update the MSY- Cmax relationship in two ways. First, they correct for the “retransformation bias” (Duan 1983) omitted in our earlier analysis, and second, they reparametrize the model using data for 109 stocks from the RAM II global database of stock assessments (Ricard et al. 2011). Their updated model is arguably more representative of global fisheries than the one we used (Srinivasan et al. 2010), and when we apply it to re-estimate global catch losses to overfishing over 1950-2004, we find that our original conclusions are strengthened.