AFSC/REFM: Alaskan flatfish chronology Black et al

Annual growth increment patterns observed in the hard parts of many marine organisms are often related to factors in the physical environment, and investigators are increasingly using dendrochronology (tree-ring science) methods to explore these relationships. Dendrochronology techniques were applied to otolith growth increments in 3 flatfish species collected from the eastern Bering Sea: northern rock sole Lepidopsetta polyxystra, yellowfin sole Limanda aspera, and Alaska plaice Pleuronectes quadrituberculatus. Within each species, otoliths were visually crossdated to ensure that the correct calendar year was assigned to each growth increment. Growth-increment widths were measured in each otolith, crossdating was statistically checked, and a master chronology was generated for each species by averaging measurement time series after age-related growth declines had been removed. The 3 final chronologies spanned 18 to 20 yr and were significantly correlated with each other, indicating a high level of growth synchrony among species. Final chronologies were compared to annual and monthly climate variables, and were most strongly related to summertime eastern Bering Sea bottom temperatures.