Publication Date:
2022-05-26
Description:
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Antarctic Science 23 (2011): 34-42, doi:10.1017/S0954102010000593.
Description:
Cycling of deep-water silicon (Si) within the Southern Ocean, and its transport
into other ocean basins, may be an important player in the uptake of
atmospheric carbon, and global climate. Recent work has shown that the Si
isotope (denoted by δ29Si or δ30Si) composition of deep-sea sponges reflects the
availability of dissolved Si during growth, and is a potential proxy for past deep
and intermediate water silicic acid concentrations. As with any geochemical
tool, it is essential to ensure analytical precision and accuracy, and consistency
between methodologies and laboratories. Analytical bias may exist between
laboratories, and sponge material may have matrix effects leading to offsets
between samples and standards. Here, we report an interlaboratory evaluation
of Si isotopes in Antarctic and subAntarctic sponges. We review independent
methods for measuring Si isotopes in sponge spicules. Our results show that
separate subsamples of non-homogenised sponges measured by three methods
yield isotopic values within analytical error for over 80% of specimens. The
relationship between δ29Si and δ30Si in sponges is consistent with kinetic
fractionation during biomineralisation. Sponge Si isotope analyses show
potential as palaeoceaongraphic archives, and we suggest Southern Ocean
sponge material would form a useful additional reference standard for future
spicule analyses.
Description:
Cruise NBP0805 was funded by NSF Office of Polar Programs (OPP) Antarctic Sciences
(grant number ANT-0636787). KH is funded by a Doherty Postdoctoral Scholarship at WHOI, and
the work has also been funded by the Natural Environment Research Council (NERC) grant
NE/F005296/1 and an Antarctic Science Bursary.
Keywords:
Biogeochemistry
;
Porifera
;
Nutrient
;
Calibration
;
Silicic acid
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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