Unlocking the potential of biological sample archives : benthic-pelagic feeding of Baltic cod assessed by otolith protein amino-acid specific stable isotope analysis

............................................................................................................... 3 INTRODUCTION ........................................................................................................ 4 MATERIAL AND METHODS .................................................................................... 10 Study area ................................................................................................................ 10 Study organism ......................................................................................................... 11 Sampling ................................................................................................................... 12 Sampling design .................................................................................................... 12 Sample Preparation ............................................................................................... 14 Extraction the organic matrix out of otoliths ........................................................... 14 Muscle samples ..................................................................................................... 15 Stable isotope analysis (SIA) .................................................................................... 16 Principle of bulk stable isotope analysis (bulk SIA) ............................................... 16 Stable isotope analysis of samples ....................................................................... 18 Principle of compound-specific stable isotope analysis (CSIA for CAA) ............ 18 Sample Preparation and Analysis for CSIA ........................................................... 19 RESULTS ................................................................................................................. 21 Relationship of otolith length / weight and cod individual data .................................. 21 bulk SIA .................................................................................................................... 22 Method applicability testing ................................................................................... 22 How do bulk SIA values (C, N, S) differ between muscle tissue and otolith protein of the same cod individual? ................................................................................... 22