Application of spatiotemporal model to fishery-independent survey data for Pacific saury

We applied a Vector Autoregressive Spatio-Temporal (VAST) model to Japanese fishery-independent survey data for predicting annual changes in spatio-temporal distribution and annual abundance indices for age 0 and age 1 of Pacific saury from 2003 to 2017. The predicted annual distribution patterns indicated that center of distribution for age 0 had slightly shifted to the east since 2010 and that density for age 1 had decreased over time. The predicted annual abundance index for age 0 indicated a similar trend with nominal, while the predicted age 1 abundance index showed a higher value than nominal particularly in 2005 and 2007.