In the first stock-wide study of tuna growth, scientists at SPC have discovered that male South Pacific albacore (Thunnus alalunga) grow larger than females, and that albacore in the central Pacific grow larger than those in the west.

Published in the journal PLoS ONE, the research article is authored by scientists from the Secretariat of the Pacific Community and Australia’s CSIRO Marine and Atmospheric Research.

The study was made possible by the dedication and significant efforts from the many fisheries observers, port samplers, fishers and scientists who participated in the collection of over 3000 otoliths (ear bones) and other biological samples from albacore across the South Pacific Ocean, from the east coast of Australia to Pitcairn Islands.

In stock assessment the growth rate is often influential and accuracy and precision in estimates are important to ensure the assessment is as accurate as feasible.  For many years, OFP has undertaken research to establish the methods to age tropical tunas and estimate their growth rates and how the environment influences growth.  Most of our work has been applied to ageing tuna using cross sections of otoliths including bigeye, yellowfin and south pacific albacore using both daily increment and annual increment techniques.