Intercalibration of age readings of deepwater black scabbardfish, Aphanopus carbo (Lowe, 1839)

Abstract

To facilitate intercalibration of the age readings of black scabbardfish, Aphanopus carbo, a collection of otoliths was exchanged among the participating laboratories in Portugal, Scotland, and Spain and a workshop was held to discuss the results. The age precision was significantly improved by the intercalibration exercises but remained relatively low. The indirect validation methods applied showed that the growth increments used for age determination were consistent. However, some discrepancies were found between otoliths from different areas, probably due to the complex spatial distribution of the species and the differing length structure, depending on the area and the method of fishing. Interpretation criteria were defined pending more definitive validation studies. © 2002 Published by Elsevier Science Ltd. on behalf of International Council for the Exploration of the Sea.