Patterns of carbon processing at the seafloor: the role of faunal and microbial communities in moderating carbon flows

Clare Woulds*, Steven Bouillon, Gregory L. Cowie, Emily Drake, Jack J. Middelburg, Ursula Witte

*Corresponding author for this work

Research output: Contribution to journalArticle

17 Citations (Scopus)
7 Downloads (Pure)

Abstract

Marine sediments, particularly those located in estuarine and coastal zones, are key locations for the burial of organic carbon (C). However, organic C delivered to the sediment is subjected to a range of biological C-cycling processes, the rates and relative importance of which vary markedly between sites, and which are thus difficult to predict. In this study, stable isotope tracer experiments were used to quantify the processing of C by microbial and faunal communities in two contrasting Scottish estuarine sites: a subtidal, organic C rich site in Loch Etive with cohesive finegrained sediment, and an intertidal, organic C poor site on an Ythan estuary sand flat with coarse-grained permeable sediments. In both experiments, sediment cores were recovered and amended with 13C labelled phytodetritus to quantify whole community respiration of the added C and to trace the isotope label into faunal and bacterial biomass. Similar respiration rates were found in Loch Etive and on the Ythan sand flat (0.64 ± 0.04 and 0.63 ± 0.12 mg C m−2h −1 , respectively), which we attribute to the experiments being conducted at the same temperature. Faunal uptake of added C over the whole experiment was markedly greater in Loch Etive (204 ± 72 mg C m−2 ) than on the Ythan sand flat (0.96 ± 0.3 mg C m−2 ), and this difference was driven by a difference in both faunal biomass and activity. Conversely, bacterial C uptake over the whole experiment in Loch Etive was much lower than that on the Ythan sand flat (1.80 ± 1.66 and 127 ± 89 mg C m−2 , respectively). This was not driven by differences in biomass, indicating that the bacterial community in the permeable Ythan sediments was particularly active, being responsible for 48 ± 18 % of total biologically processed C. This type of biological C processing appears to be favoured in permeable sediments. The total amount of biologically processed C was greatest in Loch Etive, largely due to greater faunal C uptake, which was in turn a result of higher faunal biomass. When comparing results from this study with a wide range of previously published isotope tracing experiments, we found a strong correlation between total benthic biomass (fauna plus bacteria) and total biological C processing rates. Therefore, we suggest that the total Ccycling capacity of benthic environments is primarily determined by total biomass. 
Original languageEnglish
Pages (from-to)4343-4357
Number of pages15
JournalBiogeosciences
Volume13
Issue number15
DOIs
Publication statusPublished - 4 Aug 2016

Fingerprint

microbial communities
microbial community
seafloor
carbon
biomass
lakes
sediments
sand
uptake mechanisms
experiment
sediment
phytodetritus
benthic environment
benthic zone
isotope labeling
marine sediments
marine sediment
breathing
stable isotopes
sediment core

ASJC Scopus subject areas

  • Earth-Surface Processes
  • Ecology, Evolution, Behavior and Systematics

Cite this

Patterns of carbon processing at the seafloor : the role of faunal and microbial communities in moderating carbon flows. / Woulds, Clare; Bouillon, Steven; Cowie, Gregory L.; Drake, Emily; Middelburg, Jack J.; Witte, Ursula.

In: Biogeosciences, Vol. 13, No. 15, 04.08.2016, p. 4343-4357.

Research output: Contribution to journalArticle

Woulds, Clare ; Bouillon, Steven ; Cowie, Gregory L. ; Drake, Emily ; Middelburg, Jack J. ; Witte, Ursula. / Patterns of carbon processing at the seafloor : the role of faunal and microbial communities in moderating carbon flows. In: Biogeosciences. 2016 ; Vol. 13, No. 15. pp. 4343-4357.
@article{60a2925a0f034eda9b2fbe7106e999c2,
title = "Patterns of carbon processing at the seafloor: the role of faunal and microbial communities in moderating carbon flows",
abstract = "Marine sediments, particularly those located in estuarine and coastal zones, are key locations for the burial of organic carbon (C). However, organic C delivered to the sediment is subjected to a range of biological C-cycling processes, the rates and relative importance of which vary markedly between sites, and which are thus difficult to predict. In this study, stable isotope tracer experiments were used to quantify the processing of C by microbial and faunal communities in two contrasting Scottish estuarine sites: a subtidal, organic C rich site in Loch Etive with cohesive finegrained sediment, and an intertidal, organic C poor site on an Ythan estuary sand flat with coarse-grained permeable sediments. In both experiments, sediment cores were recovered and amended with 13C labelled phytodetritus to quantify whole community respiration of the added C and to trace the isotope label into faunal and bacterial biomass. Similar respiration rates were found in Loch Etive and on the Ythan sand flat (0.64 ± 0.04 and 0.63 ± 0.12 mg C m−2h −1 , respectively), which we attribute to the experiments being conducted at the same temperature. Faunal uptake of added C over the whole experiment was markedly greater in Loch Etive (204 ± 72 mg C m−2 ) than on the Ythan sand flat (0.96 ± 0.3 mg C m−2 ), and this difference was driven by a difference in both faunal biomass and activity. Conversely, bacterial C uptake over the whole experiment in Loch Etive was much lower than that on the Ythan sand flat (1.80 ± 1.66 and 127 ± 89 mg C m−2 , respectively). This was not driven by differences in biomass, indicating that the bacterial community in the permeable Ythan sediments was particularly active, being responsible for 48 ± 18 {\%} of total biologically processed C. This type of biological C processing appears to be favoured in permeable sediments. The total amount of biologically processed C was greatest in Loch Etive, largely due to greater faunal C uptake, which was in turn a result of higher faunal biomass. When comparing results from this study with a wide range of previously published isotope tracing experiments, we found a strong correlation between total benthic biomass (fauna plus bacteria) and total biological C processing rates. Therefore, we suggest that the total Ccycling capacity of benthic environments is primarily determined by total biomass. ",
author = "Clare Woulds and Steven Bouillon and Cowie, {Gregory L.} and Emily Drake and Middelburg, {Jack J.} and Ursula Witte",
note = "Acknowledgements. The authors would like to thank Eva-Maria Zetsche, Val Johnson, Owen McPherson, Caroline Gill, and Gwylim Lynn for assistance with the Ythan sand flat fieldwork, and Matthew Schwartz, Rachel Jeffreys, Kate Larkin, Andy Gooday, and Christine Whitcraft for assistance with the Loch Etive fieldwork. Jonathan Carrivick created Fig. 1. The work was funded by the Natural Environment Research Council and the Netherlands Earth System Science Center. We would also like to thank two anonymous reviewers for their comments which helped to improve the manuscript.",
year = "2016",
month = "8",
day = "4",
doi = "10.5194/bg-13-4343-2016",
language = "English",
volume = "13",
pages = "4343--4357",
journal = "Biogeosciences",
issn = "1726-4170",
publisher = "Copernicus Gesellschaft mbH",
number = "15",

}

TY - JOUR

T1 - Patterns of carbon processing at the seafloor

T2 - the role of faunal and microbial communities in moderating carbon flows

AU - Woulds, Clare

AU - Bouillon, Steven

AU - Cowie, Gregory L.

AU - Drake, Emily

AU - Middelburg, Jack J.

AU - Witte, Ursula

N1 - Acknowledgements. The authors would like to thank Eva-Maria Zetsche, Val Johnson, Owen McPherson, Caroline Gill, and Gwylim Lynn for assistance with the Ythan sand flat fieldwork, and Matthew Schwartz, Rachel Jeffreys, Kate Larkin, Andy Gooday, and Christine Whitcraft for assistance with the Loch Etive fieldwork. Jonathan Carrivick created Fig. 1. The work was funded by the Natural Environment Research Council and the Netherlands Earth System Science Center. We would also like to thank two anonymous reviewers for their comments which helped to improve the manuscript.

PY - 2016/8/4

Y1 - 2016/8/4

N2 - Marine sediments, particularly those located in estuarine and coastal zones, are key locations for the burial of organic carbon (C). However, organic C delivered to the sediment is subjected to a range of biological C-cycling processes, the rates and relative importance of which vary markedly between sites, and which are thus difficult to predict. In this study, stable isotope tracer experiments were used to quantify the processing of C by microbial and faunal communities in two contrasting Scottish estuarine sites: a subtidal, organic C rich site in Loch Etive with cohesive finegrained sediment, and an intertidal, organic C poor site on an Ythan estuary sand flat with coarse-grained permeable sediments. In both experiments, sediment cores were recovered and amended with 13C labelled phytodetritus to quantify whole community respiration of the added C and to trace the isotope label into faunal and bacterial biomass. Similar respiration rates were found in Loch Etive and on the Ythan sand flat (0.64 ± 0.04 and 0.63 ± 0.12 mg C m−2h −1 , respectively), which we attribute to the experiments being conducted at the same temperature. Faunal uptake of added C over the whole experiment was markedly greater in Loch Etive (204 ± 72 mg C m−2 ) than on the Ythan sand flat (0.96 ± 0.3 mg C m−2 ), and this difference was driven by a difference in both faunal biomass and activity. Conversely, bacterial C uptake over the whole experiment in Loch Etive was much lower than that on the Ythan sand flat (1.80 ± 1.66 and 127 ± 89 mg C m−2 , respectively). This was not driven by differences in biomass, indicating that the bacterial community in the permeable Ythan sediments was particularly active, being responsible for 48 ± 18 % of total biologically processed C. This type of biological C processing appears to be favoured in permeable sediments. The total amount of biologically processed C was greatest in Loch Etive, largely due to greater faunal C uptake, which was in turn a result of higher faunal biomass. When comparing results from this study with a wide range of previously published isotope tracing experiments, we found a strong correlation between total benthic biomass (fauna plus bacteria) and total biological C processing rates. Therefore, we suggest that the total Ccycling capacity of benthic environments is primarily determined by total biomass. 

AB - Marine sediments, particularly those located in estuarine and coastal zones, are key locations for the burial of organic carbon (C). However, organic C delivered to the sediment is subjected to a range of biological C-cycling processes, the rates and relative importance of which vary markedly between sites, and which are thus difficult to predict. In this study, stable isotope tracer experiments were used to quantify the processing of C by microbial and faunal communities in two contrasting Scottish estuarine sites: a subtidal, organic C rich site in Loch Etive with cohesive finegrained sediment, and an intertidal, organic C poor site on an Ythan estuary sand flat with coarse-grained permeable sediments. In both experiments, sediment cores were recovered and amended with 13C labelled phytodetritus to quantify whole community respiration of the added C and to trace the isotope label into faunal and bacterial biomass. Similar respiration rates were found in Loch Etive and on the Ythan sand flat (0.64 ± 0.04 and 0.63 ± 0.12 mg C m−2h −1 , respectively), which we attribute to the experiments being conducted at the same temperature. Faunal uptake of added C over the whole experiment was markedly greater in Loch Etive (204 ± 72 mg C m−2 ) than on the Ythan sand flat (0.96 ± 0.3 mg C m−2 ), and this difference was driven by a difference in both faunal biomass and activity. Conversely, bacterial C uptake over the whole experiment in Loch Etive was much lower than that on the Ythan sand flat (1.80 ± 1.66 and 127 ± 89 mg C m−2 , respectively). This was not driven by differences in biomass, indicating that the bacterial community in the permeable Ythan sediments was particularly active, being responsible for 48 ± 18 % of total biologically processed C. This type of biological C processing appears to be favoured in permeable sediments. The total amount of biologically processed C was greatest in Loch Etive, largely due to greater faunal C uptake, which was in turn a result of higher faunal biomass. When comparing results from this study with a wide range of previously published isotope tracing experiments, we found a strong correlation between total benthic biomass (fauna plus bacteria) and total biological C processing rates. Therefore, we suggest that the total Ccycling capacity of benthic environments is primarily determined by total biomass. 

UR - http://www.scopus.com/inward/record.url?scp=84982816885&partnerID=8YFLogxK

U2 - 10.5194/bg-13-4343-2016

DO - 10.5194/bg-13-4343-2016

M3 - Article

AN - SCOPUS:84982816885

VL - 13

SP - 4343

EP - 4357

JO - Biogeosciences

JF - Biogeosciences

SN - 1726-4170

IS - 15

ER -