The multiple fates of sinking particles in the North Atlantic Ocean
Collins, James R.
Edwards, Bethanie R.
Ossolinski, Justin E.
DiTullio, Giacomo R.
Bidle, Kay D.
Doney, Scott C.
Van Mooy, Benjamin A. S.
MetadataShow full item record
KeywordCarbon cycle; Particle flux; Bacterial growth efficiency; Bacterial respiration; Microbial respiration
The direct respiration of sinking organic matter by attached bacteria is often invoked as the dominant sink for settling particles in the mesopelagic ocean. However, other processes, such as enzymatic solubilization and mechanical disaggregation, also contribute to particle flux attenuation by transferring organic matter to the water column. Here we use observations from the North Atlantic Ocean, coupled to sensitivity analyses of a simple model, to assess the relative importance of particle-attached microbial respiration compared to the other processes that can degrade sinking particles. The observed carbon fluxes, bacterial production rates, and respiration by water column and particle-attached microbial communities each spanned more than an order of magnitude. Rates of substrate-specific respiration on sinking particle material ranged from 0.007 ± 0.003 to 0.173 ± 0.105 day−1. A comparison of these substrate-specific respiration rates with model results suggested sinking particle material was transferred to the water column by various biological and mechanical processes nearly 3.5 times as fast as it was directly respired. This finding, coupled with strong metabolic demand imposed by measurements of water column respiration (729.3 ± 266.0 mg C m−2 d−1, on average, over the 50 to 150 m depth interval), suggested a large fraction of the organic matter evolved from sinking particles ultimately met its fate through subsequent remineralization in the water column. At three sites, we also measured very low bacterial growth efficiencies and large discrepancies between depth-integrated mesopelagic respiration and carbon inputs.
Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 29 (2015): 1471–1494, doi:10.1002/2014GB005037.
Suggested CitationGlobal Biogeochemical Cycles 29 (2015): 1471–1494
Showing items related by title, author, creator and subject.
Bacterial protein production on particles obtained by gravity filtration of water collected on RV/Endeavor EN556 (Patterns of activities project) Arnosti, Carol (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: firstname.lastname@example.org, 2020-05-13)Experiments on (operationally defined) particles were carried out by gravity-filtering water through 3 micron pore size filters. Bacterial protein production was measured from 3H-leucine incorporation by heterotrophic ...
Comparison of bacterial communities in sands and water at beaches with bacterial water quality violations Halliday, Elizabeth; McLellan, Sandra L.; Amaral-Zettler, Linda A.; Sogin, Mitchell L.; Gast, Rebecca J. (Public Library of Science, 2014-03-05)Recreational water quality, as measured by culturable fecal indicator bacteria (FIB), may be influenced by persistent populations of these bacteria in local sands or wrack, in addition to varied fecal inputs from human ...
Bacterial communities in penile skin, male urethra, and vaginas of heterosexual couples with and without bacterial vaginosis Zozaya, Marcela; Ferris, Michael J.; Siren, Julia D.; Lillis, Rebecca; Myers, Leann; Nsuami, M. Jacques; Eren, A. Murat; Brown, Jonathan; Taylor, Christopher M.; Martin, David H. (BioMed Central, 2016-04-19)The epidemiology of bacterial vaginosis (BV) suggests it is sexually transmissible, yet no transmissible agent has been identified. It is probable that BV-associated bacterial communities are transferred from male to female ...