MEPS 546:17-29 (2016)  -  DOI:

Quantitative estimates of sinking sea ice particulate organic carbon based on the biomarker IP25

T. A. Brown1,*, S. T. Belt1, M. Gosselin2, M. Levasseur3, M. Poulin4, C. J. Mundy5

1School of Geography, Earth and Environmental Sciences, University of Plymouth, Plymouth PL4 8AA, UK
2Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, Rimouski, Québec G5L 3A1, Canada
3Département de biologie, Québec-Océan, Université Laval, Québec, Québec G1V 0A6, Canada
4Research and Collections Division, Canadian Museum of Nature, PO Box 3443 Station D, Ottawa, Ontario K1P 6P4, Canada
5Centre for Earth Observation Science (CEOS), University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
*Corresponding author:

ABSTRACT: Sea ice-derived particulate organic carbon (iPOC) represents an important contribution of carbon to Arctic ecosystems, yet our ability to obtain realistic quantitative estimates of iPOC outside the sea ice matrix is currently somewhat limited. To address this challenge, we applied a novel approach to quantifying iPOC within the water column under melting sea ice by first measuring the proportion of the sea ice diatom biomarker IP25 within iPOC in bottom ice samples obtained from Resolute Passage during spring 2012. We then compared this value with corresponding values obtained from a time series of water samples. Together, these reflected a period of ice melt and rapid release of iPOC, indicated by changing ice temperature and thickness, in addition to changes in the stable carbon isotope composition and concentration of iPOC, IP25 and chlorophyll a within bottom ice. Estimates of iPOC in seawater were highest (0.15 to 0.22 mg l-1) in the upper 2 m, coincident with the reduction of iPOC in sea ice near the beginning of sampling, with iPOC accounting for an estimated 84 to 125% of total POC (tPOC). Collectively, this biomarker approach yielded realistic estimates of %iPOC, both numerically and in the context of melting sea ice following a spring bloom in the Canadian Arctic. We describe some assumptions of this approach and consider the impacts of possible caveats on quantitative estimates of iPOC derived using this methodology.

KEY WORDS: IP25 · Diatom · Spring sea ice bloom · POC · Carbon budget · Resolute Passage · Quantitative

Full text in pdf format 
Cite this article as: Brown TA, Belt ST, Gosselin M, Levasseur M, Poulin M, Mundy CJ (2016) Quantitative estimates of sinking sea ice particulate organic carbon based on the biomarker IP25. Mar Ecol Prog Ser 546:17-29.

Export citation
Mail this link - Contents Mailing Lists - RSS
- -