Ecological Engineering: The biogeochemical implications of faunal species loss in coastal sediments.

William Hunter, Nessa O'Connor

Research output: Contribution to conferencePaper

Abstract

Coastal and shallow seas cover 7 % of the global seafloor but account for around 80 % of carbon dioxide fixation and burial in the oceans. Consequently, they are important in the regulation of atmospheric carbon dioxide and marine nutrient cycles. Coastal ecosystems are sensitive to human-induced pressure from fisheries and pollution resulting in faunal species loss. In marine sediments, microbial activity is the biogeochemcial “engine” driving carbon fixation, recycling and burial. Yet bacterial activity is mediated by a faunal “gearbox” through processes such as bioturbation and deposit-feeding. Faunal species loss will, therefore, have indirect effects upon primary production by the microphytobenthos (primarily diatoms and cyanobacteria) at the sediment surface, and the recycling of organic matter by heterotrophic microorganisms. We conducted mesocosm-based experiments to test how changes in the presence/absence of three ecosystem engineers, the shore crab (Carcinus maenas), the ragworm (Alitta virens) and lugworm (Arenicola marina), affected micro-algal carbon fixation at the sediment surface, and the retention and transfer of newly fixed carbon within the sediment community. We used stable-isotope pulse chase techniques to trace the fixation of dissolved inorganic carbon (13C-labelled sodium bicarbonate) by the microphytobenthos and its preservation as sedimentary organic matter, alongside changes in sediment community respiration, primary production and dissolved nutrient fluxes. Here we will discuss the results of these experiments and the mechanisms through which faunal species-loss alters carbon cycling and ecosystem functioning in coastal sediment ecosystems.

Conference

Conference1st Ecology & Evolution Ireland conference
CountryIreland
CitySligo
Period25/11/1626/11/16

Fingerprint

ecological engineering
coastal sediment
carbon fixation
sediment
microbial activity
fixation
primary production
ecosystem
recycling
carbon dioxide
organic matter
deposit feeding
carbon
mesocosm
dissolved inorganic carbon
bioturbation
marina
bicarbonate
marine sediment
cyanobacterium

Cite this

Hunter, W., & O'Connor, N. (2016). Ecological Engineering: The biogeochemical implications of faunal species loss in coastal sediments.. Paper presented at 1st Ecology & Evolution Ireland conference, Sligo, Ireland.
Hunter, William ; O'Connor, Nessa. / Ecological Engineering: The biogeochemical implications of faunal species loss in coastal sediments. Paper presented at 1st Ecology & Evolution Ireland conference, Sligo, Ireland.
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title = "Ecological Engineering: The biogeochemical implications of faunal species loss in coastal sediments.",
abstract = "Coastal and shallow seas cover 7 {\%} of the global seafloor but account for around 80 {\%} of carbon dioxide fixation and burial in the oceans. Consequently, they are important in the regulation of atmospheric carbon dioxide and marine nutrient cycles. Coastal ecosystems are sensitive to human-induced pressure from fisheries and pollution resulting in faunal species loss. In marine sediments, microbial activity is the biogeochemcial “engine” driving carbon fixation, recycling and burial. Yet bacterial activity is mediated by a faunal “gearbox” through processes such as bioturbation and deposit-feeding. Faunal species loss will, therefore, have indirect effects upon primary production by the microphytobenthos (primarily diatoms and cyanobacteria) at the sediment surface, and the recycling of organic matter by heterotrophic microorganisms. We conducted mesocosm-based experiments to test how changes in the presence/absence of three ecosystem engineers, the shore crab (Carcinus maenas), the ragworm (Alitta virens) and lugworm (Arenicola marina), affected micro-algal carbon fixation at the sediment surface, and the retention and transfer of newly fixed carbon within the sediment community. We used stable-isotope pulse chase techniques to trace the fixation of dissolved inorganic carbon (13C-labelled sodium bicarbonate) by the microphytobenthos and its preservation as sedimentary organic matter, alongside changes in sediment community respiration, primary production and dissolved nutrient fluxes. Here we will discuss the results of these experiments and the mechanisms through which faunal species-loss alters carbon cycling and ecosystem functioning in coastal sediment ecosystems.",
author = "William Hunter and Nessa O'Connor",
year = "2016",
language = "English",
note = "1st Ecology & Evolution Ireland conference ; Conference date: 25-11-2016 Through 26-11-2016",

}

Hunter, W & O'Connor, N 2016, 'Ecological Engineering: The biogeochemical implications of faunal species loss in coastal sediments.' Paper presented at 1st Ecology & Evolution Ireland conference, Sligo, Ireland, 25/11/16 - 26/11/16, .

Ecological Engineering: The biogeochemical implications of faunal species loss in coastal sediments. / Hunter, William; O'Connor, Nessa.

2016. Paper presented at 1st Ecology & Evolution Ireland conference, Sligo, Ireland.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Ecological Engineering: The biogeochemical implications of faunal species loss in coastal sediments.

AU - Hunter, William

AU - O'Connor, Nessa

PY - 2016

Y1 - 2016

N2 - Coastal and shallow seas cover 7 % of the global seafloor but account for around 80 % of carbon dioxide fixation and burial in the oceans. Consequently, they are important in the regulation of atmospheric carbon dioxide and marine nutrient cycles. Coastal ecosystems are sensitive to human-induced pressure from fisheries and pollution resulting in faunal species loss. In marine sediments, microbial activity is the biogeochemcial “engine” driving carbon fixation, recycling and burial. Yet bacterial activity is mediated by a faunal “gearbox” through processes such as bioturbation and deposit-feeding. Faunal species loss will, therefore, have indirect effects upon primary production by the microphytobenthos (primarily diatoms and cyanobacteria) at the sediment surface, and the recycling of organic matter by heterotrophic microorganisms. We conducted mesocosm-based experiments to test how changes in the presence/absence of three ecosystem engineers, the shore crab (Carcinus maenas), the ragworm (Alitta virens) and lugworm (Arenicola marina), affected micro-algal carbon fixation at the sediment surface, and the retention and transfer of newly fixed carbon within the sediment community. We used stable-isotope pulse chase techniques to trace the fixation of dissolved inorganic carbon (13C-labelled sodium bicarbonate) by the microphytobenthos and its preservation as sedimentary organic matter, alongside changes in sediment community respiration, primary production and dissolved nutrient fluxes. Here we will discuss the results of these experiments and the mechanisms through which faunal species-loss alters carbon cycling and ecosystem functioning in coastal sediment ecosystems.

AB - Coastal and shallow seas cover 7 % of the global seafloor but account for around 80 % of carbon dioxide fixation and burial in the oceans. Consequently, they are important in the regulation of atmospheric carbon dioxide and marine nutrient cycles. Coastal ecosystems are sensitive to human-induced pressure from fisheries and pollution resulting in faunal species loss. In marine sediments, microbial activity is the biogeochemcial “engine” driving carbon fixation, recycling and burial. Yet bacterial activity is mediated by a faunal “gearbox” through processes such as bioturbation and deposit-feeding. Faunal species loss will, therefore, have indirect effects upon primary production by the microphytobenthos (primarily diatoms and cyanobacteria) at the sediment surface, and the recycling of organic matter by heterotrophic microorganisms. We conducted mesocosm-based experiments to test how changes in the presence/absence of three ecosystem engineers, the shore crab (Carcinus maenas), the ragworm (Alitta virens) and lugworm (Arenicola marina), affected micro-algal carbon fixation at the sediment surface, and the retention and transfer of newly fixed carbon within the sediment community. We used stable-isotope pulse chase techniques to trace the fixation of dissolved inorganic carbon (13C-labelled sodium bicarbonate) by the microphytobenthos and its preservation as sedimentary organic matter, alongside changes in sediment community respiration, primary production and dissolved nutrient fluxes. Here we will discuss the results of these experiments and the mechanisms through which faunal species-loss alters carbon cycling and ecosystem functioning in coastal sediment ecosystems.

M3 - Paper

ER -

Hunter W, O'Connor N. Ecological Engineering: The biogeochemical implications of faunal species loss in coastal sediments.. 2016. Paper presented at 1st Ecology & Evolution Ireland conference, Sligo, Ireland.