Sources and Cycling of Particulate Organic Matter in Baffin Bay: A Multi-Isotope δ13C, δ15N, and Δ14C Approach
The Canadian Arctic is warming three times faster than the rest of the planet. The impact of climate change on the Arctic carbon cycle, and in particular for Baffin Bay, remains poorly constrained. Sinking particulate organic matter (POMsink) is a key component of the biological carbon pump and prov...
Published in: | Frontiers in Marine Science |
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Frontiers Media S.A.
2022
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Online Access: | https://doi.org/10.3389/fmars.2022.846025 https://doaj.org/article/741e201a4e3b440f88fadae992b210b2 |
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ftdoajarticles:oai:doaj.org/article:741e201a4e3b440f88fadae992b210b2 2023-05-15T14:58:04+02:00 Sources and Cycling of Particulate Organic Matter in Baffin Bay: A Multi-Isotope δ13C, δ15N, and Δ14C Approach Aislinn Fox Brett D. Walker 2022-05-01T00:00:00Z https://doi.org/10.3389/fmars.2022.846025 https://doaj.org/article/741e201a4e3b440f88fadae992b210b2 EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2022.846025/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2022.846025 https://doaj.org/article/741e201a4e3b440f88fadae992b210b2 Frontiers in Marine Science, Vol 9 (2022) particulate organic matter radiocarbon 13C 15N 14C Baffin Bay Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2022 ftdoajarticles https://doi.org/10.3389/fmars.2022.846025 2022-12-30T23:18:39Z The Canadian Arctic is warming three times faster than the rest of the planet. The impact of climate change on the Arctic carbon cycle, and in particular for Baffin Bay, remains poorly constrained. Sinking particulate organic matter (POMsink) is a key component of the biological carbon pump and provides a direct linkage between surface productivity and the preservation of carbon in marine sediments. While POMsink provides a rapid POM shunt to the deep ocean (days) the majority of marine POM is suspended (POMsusp) persists for years in the water column. Stable carbon (δ13C), nitrogen (δ15N) and radiocarbon (Δ14C) measurements are powerful tools for evaluating sources and cycling of POM. In this study, we measure depth-integrated (0-400m) POMsusp stable carbon (δ13C), nitrogen (δ15N) and radiocarbon (Δ14C) values at 11 stations in Baffin Bay. We use POM C:Na ratios to evaluate its diagenetic state. POMsusp δ13C and δ15N values ranged from −21.6‰ to −29.5‰, and +3.84‰ to +7.21‰, respectively. POMsusp Δ14C values ranged from −41.8‰ to +76.8‰. Together, our results suggest Baffin Bay POMsusp has multiple carbon and nitrogen sources. POMsusp δ13C and Δ14C are strongly correlated to surface salinity, indicating surface water has a strong influence on POMsusp isotopic composition and 14C-age. POMsusp from coastal Greenland stations have similar Δ14C values to surface dissolved inorganic carbon (DIC) and POM concentrations, consistent with primary production as the predominant POMsusp source in Eastern Baffin Bay. Positive POMsusp Δ14C values in central Baffin Bay suggest an accumulation of atmospheric “bomb” 14C in the sub-polar gyre. POMsusp exiting Davis Strait via the Baffin Island Current was determined to have a significant degraded, resuspended sediment component. Finally, POMsusp δ15N values highlight two distinct N sources in Baffin Bay: Pacific and Arctic nutrients at Northern gateway stations vs. the influx of Atlantic nutrients via Davis Strait along coastal Greenland. Overall, these first Baffin Bay POMsusp ... Article in Journal/Newspaper Arctic Baffin Bay Baffin Bay Baffin Island Baffin Climate change Davis Strait Greenland Directory of Open Access Journals: DOAJ Articles Arctic Baffin Bay Baffin Island Greenland Pacific Frontiers in Marine Science 9 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
particulate organic matter radiocarbon 13C 15N 14C Baffin Bay Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
particulate organic matter radiocarbon 13C 15N 14C Baffin Bay Science Q General. Including nature conservation geographical distribution QH1-199.5 Aislinn Fox Brett D. Walker Sources and Cycling of Particulate Organic Matter in Baffin Bay: A Multi-Isotope δ13C, δ15N, and Δ14C Approach |
topic_facet |
particulate organic matter radiocarbon 13C 15N 14C Baffin Bay Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
The Canadian Arctic is warming three times faster than the rest of the planet. The impact of climate change on the Arctic carbon cycle, and in particular for Baffin Bay, remains poorly constrained. Sinking particulate organic matter (POMsink) is a key component of the biological carbon pump and provides a direct linkage between surface productivity and the preservation of carbon in marine sediments. While POMsink provides a rapid POM shunt to the deep ocean (days) the majority of marine POM is suspended (POMsusp) persists for years in the water column. Stable carbon (δ13C), nitrogen (δ15N) and radiocarbon (Δ14C) measurements are powerful tools for evaluating sources and cycling of POM. In this study, we measure depth-integrated (0-400m) POMsusp stable carbon (δ13C), nitrogen (δ15N) and radiocarbon (Δ14C) values at 11 stations in Baffin Bay. We use POM C:Na ratios to evaluate its diagenetic state. POMsusp δ13C and δ15N values ranged from −21.6‰ to −29.5‰, and +3.84‰ to +7.21‰, respectively. POMsusp Δ14C values ranged from −41.8‰ to +76.8‰. Together, our results suggest Baffin Bay POMsusp has multiple carbon and nitrogen sources. POMsusp δ13C and Δ14C are strongly correlated to surface salinity, indicating surface water has a strong influence on POMsusp isotopic composition and 14C-age. POMsusp from coastal Greenland stations have similar Δ14C values to surface dissolved inorganic carbon (DIC) and POM concentrations, consistent with primary production as the predominant POMsusp source in Eastern Baffin Bay. Positive POMsusp Δ14C values in central Baffin Bay suggest an accumulation of atmospheric “bomb” 14C in the sub-polar gyre. POMsusp exiting Davis Strait via the Baffin Island Current was determined to have a significant degraded, resuspended sediment component. Finally, POMsusp δ15N values highlight two distinct N sources in Baffin Bay: Pacific and Arctic nutrients at Northern gateway stations vs. the influx of Atlantic nutrients via Davis Strait along coastal Greenland. Overall, these first Baffin Bay POMsusp ... |
format |
Article in Journal/Newspaper |
author |
Aislinn Fox Brett D. Walker |
author_facet |
Aislinn Fox Brett D. Walker |
author_sort |
Aislinn Fox |
title |
Sources and Cycling of Particulate Organic Matter in Baffin Bay: A Multi-Isotope δ13C, δ15N, and Δ14C Approach |
title_short |
Sources and Cycling of Particulate Organic Matter in Baffin Bay: A Multi-Isotope δ13C, δ15N, and Δ14C Approach |
title_full |
Sources and Cycling of Particulate Organic Matter in Baffin Bay: A Multi-Isotope δ13C, δ15N, and Δ14C Approach |
title_fullStr |
Sources and Cycling of Particulate Organic Matter in Baffin Bay: A Multi-Isotope δ13C, δ15N, and Δ14C Approach |
title_full_unstemmed |
Sources and Cycling of Particulate Organic Matter in Baffin Bay: A Multi-Isotope δ13C, δ15N, and Δ14C Approach |
title_sort |
sources and cycling of particulate organic matter in baffin bay: a multi-isotope δ13c, δ15n, and δ14c approach |
publisher |
Frontiers Media S.A. |
publishDate |
2022 |
url |
https://doi.org/10.3389/fmars.2022.846025 https://doaj.org/article/741e201a4e3b440f88fadae992b210b2 |
geographic |
Arctic Baffin Bay Baffin Island Greenland Pacific |
geographic_facet |
Arctic Baffin Bay Baffin Island Greenland Pacific |
genre |
Arctic Baffin Bay Baffin Bay Baffin Island Baffin Climate change Davis Strait Greenland |
genre_facet |
Arctic Baffin Bay Baffin Bay Baffin Island Baffin Climate change Davis Strait Greenland |
op_source |
Frontiers in Marine Science, Vol 9 (2022) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2022.846025/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2022.846025 https://doaj.org/article/741e201a4e3b440f88fadae992b210b2 |
op_doi |
https://doi.org/10.3389/fmars.2022.846025 |
container_title |
Frontiers in Marine Science |
container_volume |
9 |
_version_ |
1766330144019972096 |