Experimental determination of the sources of otolith carbon and associated isotopic fractionation
| Autor: | B. Lynn Ingram, Christopher T. Solomon, Mark E. Conrad, Asya R Pogodina, P K Weber, Joseph J. Cech, M. V. Machavaram, Rebecca L Franklin |
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| Rok vydání: | 2006 |
| Předmět: |
0106 biological sciences
010604 marine biology & hydrobiology chemistry.chemical_element Mineralogy Fractionation Aquatic Science 010603 evolutionary biology 01 natural sciences medicine.anatomical_structure chemistry Aquatic environment Isotopes of carbon medicine Environmental science Carbon Ecology Evolution Behavior and Systematics Otolith |
| Zdroj: | Canadian Journal of Fisheries and Aquatic Sciences. 63:79-89 |
| ISSN: | 1205-7533 0706-652X |
| Popis: | Otolith stable carbon isotope ratios provide a unique and widely applicable environmental record. Unfortunately, uncertainty regarding the proportion of otolith carbon that derives from metabolized food versus dissolved inorganic carbon (DIC) in the water currently limits utilization of this marker. We manipulated the δ13C of food and ambient DIC in a factorial design with juvenile rainbow trout (Oncorhynchus mykiss). At the activity levels and total metabolic rates characteristic of fish in this study, 17% (±3% standard error, SE) of otolith C was metabolically derived, while >80% was derived from DIC in ambient water. We also estimated isotopic enrichment factors associated with physiological carbon transformations by measuring δ13C of blood and endolymph (which closely tracked otolith δ13C). There was substantial depletion in13C of blood relative to C sources (εbloodsources = 16.9 ± 1.1 SE), but substantial enrichment in13C in otolith relative to blood (εotoblood = 13.3 ± 1.3 SE). Net isotopic enrichment between sources and the otolith was therefore slightly negative. Most of the isotopic enrichment between the blood and the otolith was associated with the movement of C from blood to endolymph, while enrichment associated with the precipitation of otolith aragonite from the endolymph was small. |
| Databáze: | OpenAIRE |
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