Report from The Herring Age Reading Workshop

As a part of the process of herring stock assessment, age determinations of herring are conducted in several laboratories in Atlantic and Baltic coastal areas. Age determination errors have been identified as one possible factor reducing the accuracy of stock assessment.

The aim of the workshop was to identify present problems in herring age determination, improve the accuracy and precision of age determinations and spread information of the methods and procedures used in different ageing laboratories working with herring.

In the workshop, two groups of age determination laboratories that have had co-operation inside each group before, those at the Atlantic coastal areas and those at Baltic Sea coastal areas were working together. The common meeting benefited both groups by changing experience of different practices and spreading knowledge of herring growth and otoliths in different conditions from those populations and areas each one was familiar with.

Before the workshop, four different samples of otoliths were circulated among different laboratories to assess the precision of age readers. Preliminary results from the circulation were presented in the workshop and discussed together.

EU data collection programme funded the participation of two members per EU member country.