Fig. 4: Decadal prediction of cod stocks.
From: Skilful prediction of cod stocks in the North and Barents Sea a decade in advance
a Time series of retrospective predictions of total stock biomass (TSB) of North Sea cod using the dynamical–statistical prediction model (retrospective predictions of North Sea surface temperature combined with the linear statistical temperature–cod relationship) for the period 1971–2019 using the initialized hindcast and historical simulation of North Sea surface temperature. The observed TSB is shown by blue circles. Also provided is the forecast for the period 2020–2030 comprising three fishing mortality scenarios: status quo (FSQ = 0.50), maximum sustainable yield (FMSY = 0.30), and precautionary approach (FLIM = 0.54). The bars and whiskers show the 95% confidence limits (2.5th, 25th, 50th, 75th, and 97.5th percentiles are shown) for the respective forecasts for the whole period (2020–2030). The historical North Sea surface temperature is extended using the RCP8.5 scenario for issuing forecasts of cod biomass. b Anomaly correlation coefficient (ACC) and mean square error skill score (MSESS) for the retrospective North Sea cod TSB prediction (1971–2019) with respect to observations. The whiskers show 95% confidence limits. c, d Same as (a, b) but for Northeast Arctic cod and using initialized hindcasts and historical simulation of SPG temperature. For the forecast, assumed fishing mortality scenarios are FSQ = 0.42, FMSY = 0.4 and FLIM = 0.74. The shadings in (a and c) show 95% confidence limits.
