Experimental assessment of the effect of temperature and salinity on elemental composition of otoliths using laser ablation ICPMS

1995 ◽  
Vol 52 (7) ◽  
pp. 1431-1441 ◽  
Author(s):  
Anthony J. Fowler ◽  
Steven E. Campana ◽  
Simon R. Thorrold ◽  
Cynthia M. Jones

Laser ablation – inductively coupled plasma mass spectrometry (LA-ICPMS) is a new technique that can be used for the multielemental analysis of otoliths at specific loci. This method was used to sample the otoliths of Atlantic croaker (Micropogonias undulatus), reared under different constant regimes of temperature and salinity, to determine whether the elemental composition of otoliths changes ontogenetically. Each otolith was sampled at a number of loci, beginning at the center and then every 500 μm along the longest axis to near the edge; of 23 isotopes measured simultaneously at each locus, 18 were standardized to 48Ca and included in analyses. The elemental composition at otolith centers and near their edges differed significantly amongst treatments, with the effect of temperature a stronger influence. Elemental composition also varied across otoliths from within treatments, indicating endogenous effects. Ontogenetic patterns differed amongst treatments, indicating that endogenous control was mediated by the external environment. Otoliths of fish from one tank where the physical conditions were switched, showed greater variation in the multielemental signal than that resulting only from ontogenetic change. All analyses indicated that otolith formation is the product of numerous interactive exogenous and endogenous processes, including water temperature, salinity, and ontogeny.

1995 ◽  
Vol 52 (7) ◽  
pp. 1421-1430 ◽  
Author(s):  
Anthony J. Fowler ◽  
Steven E. Campana ◽  
Simon R. Thorrold ◽  
Cynthia M. Jones

Retrospective determination of the early life history of fish using the microelemental analysis of their otoliths is dependent upon understanding the factors that affect this elemental composition. Here, juvenile Atlantic croaker (Micropogonias undulatus) were reared under different treatments of temperature and salinity to determine their impacts on elemental inclusion rates in otoliths. Solution-based inductively coupled plasma mass spectrometry (ICPMS) was used to measure 21 isotopes in each otolith: isotopic concentrations ranged over seven orders of magnitude, and differed significantly amongst the temperature–salinity regimes. Univariate analyses identified 13 isotopes that contributed to these multivariate differences; the influence of temperature was stronger than that of salinity. Within each treatment there was a significant relationship between otolith microchemistry and otolith size. To some extent this confounded the interpretation of the between-treatment effect of temperature. In contrast, both the otolith and somatic growth rates were similar between the two salinity treatments, indicating that differences in elemental fingerprints were unambiguously related to the salinity difference, probably a response to the elemental concentrations in the tank water. Overall the study highlighted the current poor understanding of the mechanism of contamination of otoliths by trace elements and their incorporation into the otolith microstructure.


2005 ◽  
Vol 59 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Belinda Flem ◽  
Vidar Moen ◽  
Andreas Grimstvedt

The pre-smolt stage of the scale of adult Norwegian Atlantic salmon from four populations, encompassing both farmed and wild hatchery stocks, has been analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-HR-ICP-MS). The purpose of this study was to test for differences in elemental composition between stocks of Atlantic salmon that have lived in separate fresh water locations until the smoltification and natural run out or transportation to the sea-cages. The populations studied were from fish farms located at Bremanger and Sørfold, a cultivated stock from Mossa, and one wild local stock from the river Gaula. The following elements were included in the analytical protocol: Li, Mg, Ca, Cr, Mn, Fe, Zn, Sr, Ba, Pb, and U. Calcium was used as a natural internal standard. Classification of the analytical data is studied by multivariate statistical techniques such as principal component analysis (PCA). We have been able to delineate the population of Atlantic salmon ( Salmo salar L.) from Gaula and Mossa from the Bremanger and the Sørfold stock based on the ten elements analyzed. The Bremanger and Sørfold stocks were partially delineated. The differences in elemental composition in the scales, which makes the delineating of the four stocks possible, probably reflects geological differences in the bedrock at the four fresh water locations experienced by the salmon during the pre-smolt stage.


1997 ◽  
Vol 54 (9) ◽  
pp. 2068-2079 ◽  
Author(s):  
S E Campana ◽  
S R Thorrold ◽  
C M Jones ◽  
D Günther ◽  
M Tubrett ◽  
...  

The elemental composition of fish otoliths is of considerable interest to those who wish to reconstruct temperature, migration, or environmental histories of individual fish based on assays of the otolith growth sequence. However, reported differences in otolith elemental composition among studies may be due in part to performance differences among four of the most popular instruments for targeted elemental analysis: wavelength-dispersive electron microprobe (WD-EM), energy-dispersive electron microprobe (ED-EM), proton-induced X-ray emission (PIXE), and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). To rigorously compare the sensitivity, accuracy, and precision of these four analytical tools, the International Otolith Composition Experiment distributed blind-labelled real and artificial otoliths of known but varied elemental composition to eight laboratories for assay of 10 selected elements. No one instrument type was sensitive to each element, nor was any one instrument preferred for use in all assays. In general however, abundant elements such as Na and K could only be measured accurately with an electron microprobe, while the trace elements required PIXE or LA-ICPMS. Strontium could be measured with considerable accuracy and precision by WD-EM, PIXE, and LA-ICPMS. The presence of significant, and occasionally large, differences among laboratories suggests that comparisons among published studies should be made cautiously and only after appropriate calibration.


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