03. Sep 2020

Accurate age determination of long-lived fishes is essential to sustainable fisheries management and understanding the direct effects of climate changes on population dynamics. Our project is improving age estimates of long-lived redfish Sebastes norvegicus from the north of Norway and Svalbard by applying advanced techniques from the fields of dendro- and sclerochronology to otoliths. Advanced laboratory preparation, imaging, and statistical techniques will result in the development of long-term, exactly dated, growth chronologies that will be compared to traditional aging methods. Redfish growth chronologies and recruitment histories will be correlated with environmental time series to identify relationships between physical drivers and biological responses. Together, the results from this project will substantially improve our understanding of redfish life history characteristics in the Arctic. Results obtained during the first year of funding demonstrate that the approach is effective: An initial master chronology spanning from 1968-2010 has been developed. For these years, there is a positive correlation between S. norvegicus growth and sea surface temperature during summer months. More data are needed to confirm and refine these findings. We seek funding to continue adding more samples to the chronology and publish our results.