@article {2779,
	title = {Tracing biogeochemical subsidies from glacier runoff into Alaska{\textquoteright}s coastal marine food webs},
	journal = {Global Change Biology},
	volume = {24},
	year = {2018},
	month = {Jan-01-2018},
	pages = {387 - 398},
	abstract = {Nearly half of the freshwater discharge into the Gulf of Alaska originates from landscapes draining glacier runoff, but the influence of the influx of riverine organic matter on the trophodynamics of coastal marine food webs is not well understood. We quantified the ecological impact of riverine organic matter subsidies to glacier-marine habitats by developing a multi-trophic level Bayesian three-isotope mixing model. We utilized large gradients in stable (δ13C, δ15N, δ2H) and radiogenic (Δ14C) isotopes that trace riverine and marine organic matter sources as they are passed from lower to higher trophic levels in glacial-marine habitats. We also compared isotope ratios between glacial-marine and more oceanic habitats. Based on isotopic measurements of potential baseline sources, ambient water and tissues of marine consumers, estimates of the riverine organic matter source contribution to upper trophic-level species including fish and seabirds ranged from 12\% to 44\%. Variability in resource use among similar taxa corresponded to variation in species distribution and life histories. For example, riverine organic matter assimilation by the glacier-nesting seabirds Kittlitz{\textquoteright}s murrelet (Brachyramphus brevirostris) was greater than that of the forest-nesting marbled murrelet (B. marmoratus). The particulate and dissolved organic carbon in glacial runoff and near surface coastal waters was aged (12100{\textendash}1500 years BP 14C-age) but dissolved inorganic carbon and biota in coastal waters were young (530 years BP 14C-age to modern). Thus terrestrial-derived subsidies in marine food webs were primarily composed of young organic matter sources released from glacier ecosystems and their surrounding watersheds. Stable isotope compositions also revealed a divergence in food web structure between glacial-marine and oceanic sites. This work demonstrates linkages between terrestrial and marine ecosystems, and facilitates a greater understanding of how climate-driven changes in freshwater runoff have the potential to alter food web dynamics within coastal marine ecosystems in Alaska.},
	keywords = {Bayesian isotope mixing model, glacier runoff, marine ecosystem, marine food web, δ13C, Δ14C, δ15N, δ2H},
	doi = {10.1111/gcb.2018.24.issue-110.1111/gcb.13875},
	url = {https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.13875},
	author = {Arimitsu, Mayumi L. and Hobson, Keith A. and Webber, D{\textquoteright}Arcy N. and Piatt, John F. and Hood, Eran W. and Fellman, Jason B.}
}
@article {2461,
	title = {Spatial Variation in the Origin of Dissolved Organic Carbon in Snow on the Juneau Icefield, Southeast Alaska},
	journal = {Environmental Science \& Technology},
	volume = {49},
	year = {2015},
	month = {Jun-10-2015},
	pages = {11492 - 11499},
	abstract = {Dissolved organic carbon (DOC) plays a fundamental role in the biogeochemistry of glacier ecosystems. However, the specific sources of glacier DOC remain unresolved. To assess the origin and nature of glacier DOC, we collected snow from 10 locations along a transect across the Juneau Icefield, Alaska extending from the coast toward the interior. The Δ14C-DOC of snow varied from -743 to -420{\textperthousand} showing progressive depletion across the Icefield as δ18O of water became more depleted (R2 = 0.56). Older DOC corresponded to lower DOC concentrations in snow (R2 = 0.31) and a decrease in percent humic-like fluorescence (R2 = 0.36), indicating an overall decrease in modern DOC across the Icefield. Carbon isotopic signatures (13C and 14C) combined with a three-source mixing model showed that DOC deposited in snow across the Icefield reflects fossil fuel combustion products (43{\textendash}73\%) and to a lesser extent marine (21{\textendash}41\%) and terrestrial sources (1{\textendash}26\%). Our finding that combustion aerosols are a large source of DOC to the glacier ecosystem during the early spring (April{\textendash}May) together with the pronounced rates of glacier melting in the region suggests that the delivery of relic DOC to the ocean may be increasing and consequently impacting the biogeochemistry of glacial and proglacial ecosystems in unanticipated ways.},
	issn = {0013-936X},
	doi = {10.1021/acs.est.5b02685},
	url = {http://pubs.acs.org/doi/10.1021/acs.est.5b02685http://pubs.acs.org/doi/pdf/10.1021/acs.est.5b02685},
	author = {Fellman, Jason B. and Hood, Eran and Raymond, Peter A. and Stubbins, Aron and Spencer, Robert G.M.}
}
