Shape Analysis and Microchemistry of Redfish Otoliths: Investigation of Geographical Differences in the North Atlantic

• Main Author: Christoph Stransky
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2003
• Subjects: Otolith shape analysis; Fourier analysis; trace element analysis; elemental assays; otolith microchemistry; LA-ICPMS; deep-sea redfish; golden redfish; Sebastes mentella; Sebastes marinus; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.498.5011; http://www.redfish.de/project/deliv16.pdf

As part of an ongoing EU project on redfish, otolith shape analysis and otolith trace element assays were conducted to test for differences between distribution areas. Otolith morphometry and shape (Fourier) descriptors were compared between sampling areas of golden redfish (Sebastes marinus) and deep-sea redfish (Sebastes mentella) in the North Atlantic. A first series of trace element assays was performed using laser-ablation inductively coupled plasma mass spectrometry (LA-ICPMS) on cross-sections of S. mentella otoliths. Geographical separation by these methods appeared to be weak, although some distinction of western, central and eastern areas was apparent for otolith shapes of S. marinus. Trace element concentrations in S. mentella otoliths differed between three otolith zones (core, 3-year annulus and edge), giving first hints to physiological effects and/or migration. Differences in elemental concentrations between areas showed repeated patterns for some elements, indicating area-specific signatures. Multivariate analysis of these signatures, however, revealed no clear discrimination of distribution areas. Since the otolith shape analysis was limited to material from medium-sized fish (30-40 cm total length) and microchemical assays were only performed on a sub-set of S. mentella otoliths, further investigations will be carried out during the next months to reveal more information on possible natural markers for redfish.