| Popis: |
The Workshop on Age Reading of Greenland Cod (WKARGC, September 1-4, 2009) was co-chaired by Einar Hjörleifsson and Heino Fock. Three nations took part (Iceland, Germany, Greenland) with 11 participants. This was the first workshop after a long period of cessation of Greenland cod work. Thus, the main objective was to improve age reading for the cod stock off Greenland and in particular to improve age reading for the East Greenland stock component. The East Greenland shelf is a complex ecosystem with many environmental influences, and knowledge from the 1980's shows that otolith structures from there are difficult to read. During three different reading rounds and respective laboratory work, overall reading expertise could be improved though the levels of agreements between reader obtained in workshops in the 1980's could not be achieved. It appeared during the workshop that different techniques were applied to prepare and read otoliths, so that the intercalibration test was likely biased due to different levels of experience with any one of methods. Recommendations from the workshop were: To implement an extensive exchange and training program with the aim to foster reading capabilities of new age readers and to improve the overall performance. This program will start in 2009. To apply a classification and grading system to account for otolith quality and readability. This will start in 2010 for German laboratory, the Icelandic lab has already established such a system. To prepare a manual comprising images of annotated and validated otoliths to foster intersessional work prior to a next WKARGC. To work on validation tools for age reading in terms of cohort analysis. This will be reported to NWWG in 2010. |
