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dc.contributor.authorStasko, Ashley D
dc.contributor.authorBluhm, Bodil
dc.contributor.authorReist, James D
dc.contributor.authorSwanson, Heidi
dc.contributor.authorPower, Michael
dc.date.accessioned2019-03-04T09:38:30Z
dc.date.available2019-03-04T09:38:30Z
dc.date.issued2018-03-27
dc.description.abstractStable isotope ratios of nitrogen (δ<sup>15</sup>N) of benthic primary consumers are often significantly related to water depth. This relationship is commonly attributed to preferential uptake of <sup>14</sup>N from sinking particulate organic matter (POM) by microbes, and suggests that relationships between δ<sup>15</sup>N and water depth may be affected by local POM sources and flux dynamics. We examined the relationships between δ<sup>15</sup>N and water depth (20–500 m) for six trophic functional groups using a mixed effects modelling approach, and compared relationships between two contiguous Arctic marine ecosystems with different POM sources and sinking export dynamics: the Canadian Beaufort Sea and Amundsen Gulf. We demonstrate for the first time in the Arctic that δ<sup>15</sup>N values of mobile epifaunal carnivores increased as a function of depth when considered separately from benthopelagic and infaunal carnivores, which contrarily did not exhibit increasing δ<sup>15</sup>N with depth. The δ<sup>15</sup>N of suspension/filter feeders, infaunal deposit feeders and bulk sediment also increased with water depth, and the slopes of the relationships were steeper in the Amundsen Gulf than in the Beaufort Sea. We propose that regional differences in slopes reflect differences in POM sources exported to the benthos. In the Beaufort Sea, terrestrial POM discharged from the Mackenzie River quantitatively dominates the sedimentary organic matter across the continental shelf and slope, dampening change in δ<sup>15</sup>N of benthic POM with depth. In the Amundsen Gulf, we attribute a faster rate of change in δ<sup>15</sup>N of POM with increasing depth to larger contributions of marine-derived POM to the benthic sedimentary pool, which had likely undergone extensive biological transformation in the productive offshore pelagic zone. Differences in POM input regimes among regions should be considered when comparing food webs using stable isotopes, as such differences may impact the rate at which consumer δ<sup>15</sup>N changes with depth.en_US
dc.description.sponsorshipFisheries Joint Management Committee (Inuvik, NWT) Aboriginal Affairs and Northern Development Canada (BREA) Natural Resources Canada (Environmental Research Fund, Program of Energy Research and Development) internal Fisheries National Sciences and Engineering Research Council (NSERC) NSERC Alexander Graham Bell CGS D NSERC Michael Smith Foreign Study Supplement scholarships UiT– The Arctic University of Norwayen_US
dc.descriptionSubmitted manuscript version. Published version available at <a href=https://doi.org/10.1016/j.dsr.2018.03.010>https://doi.org/10.1016/j.dsr.2018.03.010. </a>en_US
dc.identifier.citationStasko, A.D., Bluhm, B.A., Reist, J.D., Swanson, H. & Power, M. (2018). Relationships between depth and δ<sup>15</sup>N of Arctic benthos vary among regions and trophic functional groups. <i>Deep Sea Research Part I: Oceanographic Research Papers, 135, </i>56 - 64. https://doi.org/10.1016/j.dsr.2018.03.010en_US
dc.identifier.cristinIDFRIDAID 1629416
dc.identifier.doi10.1016/j.dsr.2018.03.010
dc.identifier.issn0967-0637
dc.identifier.issn1879-0119
dc.identifier.urihttps://hdl.handle.net/10037/14811
dc.language.isoengen_US
dc.publisherElsevieren_US
dc.relation.journalDeep Sea Research Part I: Oceanographic Research Papers
dc.rights.accessRightsopenAccessen_US
dc.subjectMarine fishen_US
dc.subjectBenthic invertebratesen_US
dc.subjectStable isotopesen_US
dc.subjectWater depthen_US
dc.subjectArcticen_US
dc.subjectFunctional groupsen_US
dc.subjectVDP::Mathematics and natural science: 400::Zoology and botany: 480en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480en_US
dc.titleRelationships between depth and δ15N of Arctic benthos vary among regions and trophic functional groupsen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US


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