@article { ISI:000327814700020,
	title = {Prominent bacterial heterotrophy and sources of C-13-depleted fatty acids to the interior Canada Basin},
	journal = {BIOGEOSCIENCES},
	volume = {10},
	number = {{11}},
	year = {2013},
	pages = {7065-7080},
	type = {Article},
	abstract = {In recent decades, the Canada Basin of the Arctic Ocean has experienced rapidly decreasing summer sea ice coverage and freshening of surface waters. It is unclear how these changes translate to deeper waters, particularly as our baseline understanding of organic carbon cycling in the deep basin is quite limited. In this study, we describe full-depth profiles of the abundance, distribution and carbon isotopic composition of fatty acids from suspended particulate matter at a seasonally ice-free station and a semi-permanently ice-covered station. Fatty acids, along with suspended particulate organic carbon (POC), are more concentrated and C-13-enriched under ice cover than in ice-free waters. But this influence, apparent at 50 m depth, does not propagate downward below 150m depth, likely due to the weak biological pump in the central Canada Basin. Branched fatty acids have delta C-13 values that are similar to suspended POC at all depths and are more C-13-enriched than even-numbered saturated fatty acids at depths above 3000 m. These are likely to be produced in situ by heterotrophic bacteria incorporating organic carbon that is isotopically similar to total suspended POC. Below surface waters, there is also the suggestion of a source of saturated even-numbered fatty acids which could represent contributions from laterally advected organic carbon and/or from chemoautotrophic bacteria. At 3000 m depth and below, a greater relative abundance of long-chain (C20-24), branched and unsaturated fatty acids is consistent with a stronger influence of re-suspended sedimentary organic carbon. At these deep depths, two individual fatty acids (C-12 and iso-C-17) are significantly depleted in C-13, allowing for the possibility that methane oxidizing bacteria contribute fatty acids, either directly to suspended particulate matter or to shallow sediments that are subsequently mobilized and incorporated into suspended particulate matter within the deep basin.},
	issn = {1726-4170},
	doi = {10.5194/bg-10-7065-2013},
	author = {Shah, S. R. and Griffith, D. R. and Galy, V. and McNichol, A. P. and Eglinton, T. I.}
}
@article {153,
	title = {Carbon dynamics in the western Arctic Ocean: insights from full-depth carbon isotope profiles of DIC, DOC, and POC},
	journal = {Biogeosciences},
	volume = {9},
	year = {2012},
	note = {id: 2254; PT: J; TC: 4; UT: WOS:000302179500026},
	pages = {1217-1224},
	abstract = {Arctic warming is projected to continue throughout the coming century. Yet, our currently limited understanding of the Arctic Ocean carbon cycle hinders our ability to predict how changing conditions will affect local Arctic ecosystems, regional carbon budgets, and global climate. We present here the first set of concurrent, full-depth, dual-isotope profiles for dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and suspended particulate organic carbon (POCsusp) at two sites in the Canada Basin of the Arctic Ocean. The carbon isotope composition of sinking and suspended POC in the Arctic contrasts strongly with open ocean Atlantic and Pacific sites, pointing to a combination of inputs to Arctic POCsusp at depth, including surface-derived organic carbon (OC), sorbed/advected OC, and OC derived from in situ DIC fixation. The latter process appears to be particularly important at intermediate depths, where mass balance calculations suggest that OC derived from in situ DIC fixation contributes up to 22\% of POCsusp. As in other oceans, surface-derived OC is still a dominant source to Arctic POCsusp. Yet, we suggest that significantly smaller vertical POC fluxes in the Canada Basin make it possible to see evidence of DIC fixation in the POCsusp pool even at the bulk isotope level.},
	issn = {1726-4170},
	doi = {10.5194/bg-9-1217-2012},
	author = {Griffith, D. R. and McNichol, A. P. and Xu, L. and McLaughlin, F. A. and Macdonald, R. W. and Brown, K. A. and Eglinton, T. I.}
}
@article {402,
	title = {Inputs of Fossil Carbon from Wastewater Treatment Plants to US Rivers and Oceans},
	journal = {Environmental Science \& Technology},
	volume = {43},
	year = {2009},
	note = {id: 1833; 476XR Times Cited:0 Cited References Count:51Y},
	pages = {5647-5651},
	abstract = {Every day more than 500 million cubic meters of treated wastewater are discharged into rivers, estuaries, and oceans, an amount slightly less than the average flow of the Danube River. Typically, wastewaters have high organic carbon [OC) concentrations and represent a large fraction of total river flow and a higher fraction of river OC in densely populated watersheds. Here, we report the first direct measurements of radiocarbon (C-14) in municipal wastewater treatment plant (WWTP) effluent. The radiocarbon ages of particulate and dissolved organic carbon (POC and DOC) in effluent are old and relatively uniform across a range of WWTPs in New York and Connecticut. Wastewater DOC has a mean radiocarbon age of 1630 +/- 500 years B.P. and a mean delta C-13 of -26.0 +/- 1 parts per thousand. Mass balance calculations indicate that 25\% of wastewater DOC is fossil carbon, which is likely derived from petroleum-based household products such as detergents and pharmaceuticals. These findings warrant reevaluation of the "apparent age" of riverine DOC, the total flux of petroleum carbon to U.S. oceans, and OC source assignments in waters impacted by sewage.},
	issn = {0013-936X},
	doi = {10.1021/As9004043},
	author = {Griffith, D. R. and Barnes, R. T. and Raymond, P. A.}
}
