Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Geochemical Exploration 102 (2009): 181-186, doi:10.1016/j.gexplo.2008.10.001.
Description:
Isotope ratios and elemental concentrations in otoliths are often used as natural tags to
reconstruct migratory movements and connectivity patterns in marine and
anadromous fishes. Although differences in otolith geochemistry have been
documented among geographically separated populations, inter-annual variation
within locations is less frequently examined. We compared otolith isotope (δ18O and
87Sr:86Sr) and elemental ratios (Sr:Ca and Ba:Ca) from several annual cohorts of
juvenile American shad (Alosa sapidissima) in three rivers. These four geochemical
signatures distinguished among river-specific populations of this species at both large
and small geographic scales, with δ18O and 87Sr:86Sr generating the majority of
multivariate variation. We found significant variation among years for all variables in
two to three rivers. However, the magnitude of variability differed among ratios, with
δ18O ratios showing substantial inter-annual shifts while 87Sr:86Sr ratios were
relatively stable across years. Sr:Ca and Ba:Ca ratios also varied among years. These
results imply that investigators using environmentally labile signatures must quantify
geochemical signatures for each cohort of interest in order to confidently identify
origins of migrants.
Description:
Funding was provided by National Science Foundation grants to SRT
(OCE-0215905 and OCE-0134998) and grants by the American Museum of Natural
History Lerner-Gray Fund for Marine Research, SEASPACE, Inc., and the WHOI
Ocean Life Institute to BDW.
Keywords:
Otolith chemistry
;
Strontium isotopes
;
Oxygen isotopes
;
Inter-annual variability
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
Permalink
