Discrimination of Juvenile Red Snapper Otolith Chemical Signatures from Gulf of Mexico Nursery Regions
Age-0 red snapper Lutjanus campechanus from the 2005-2007 year-classes were sampled in six regions across the Gulf of Mexico (Gulf) to develop nursery signatures from otolith element : Ca ratios (Ba:Ca, Mg:Ca, Mn:Ca, Sr:Ca, and Li:Ca) and stable isotope delta values (delta C-13 and delta O-18). Element : Ca ratios were analyzed with sector field inductively coupled plasma mass spectrometry on dissolved right sagittae; isotope ratio mass spectrometry was employed to analyze pulverized left otoliths for delta C-13 and delta O-18. Otolith chemical signatures were significantly different among regions in each year. Year-class-specific quadratic discriminant function analysis (QDFA) distinguished nursery regions with an accuracy of 82% for 2005, 70% for 2006, and 72% for 2007. However, samples were not obtained from all six study regions in 2005 and 2006. A QDFA of all year-classes combined produced an overall classification accuracy of 70%, thus indicating that region-specific otolith chemical signatures from adjacent sampling years could be used as surrogates for regions where samples were not obtained in a given year.
MARINE AND COASTAL FISHERIES
Shiller, A. M.
(2012). Discrimination of Juvenile Red Snapper Otolith Chemical Signatures from Gulf of Mexico Nursery Regions. MARINE AND COASTAL FISHERIES, 4(1), 587-1097.
Available at: http://aquila.usm.edu/fac_pubs/7615