The University of Southampton
University of Southampton Institutional Repository
Warning ePrints Soton is experiencing an issue with some file downloads not being available. We are working hard to fix this. Please bear with us.

Connected macroalgal-sediment systems: blue carbon and food webs in the deep coastal ocean

Connected macroalgal-sediment systems: blue carbon and food webs in the deep coastal ocean
Connected macroalgal-sediment systems: blue carbon and food webs in the deep coastal ocean
Macroalgae drive the largest CO2 flux fixed globally by marine macrophytes. Most of the resulting biomass is exported through the coastal ocean as detritus and yet almost no field measurements have verified its potential net sequestration in marine sediments. This gap limits the scope for the inclusion of macroalgae within blue carbon schemes that support ocean carbon sequestration globally, and the understanding of the role their carbon plays within distal food webs. Here, we pursued three lines of evidence (eDNA sequencing, Bayesian Stable Isotope Mixing Modeling, and benthic-pelagic process measurements) to generate needed, novel data addressing this gap. To this end, a 13-month study was undertaken at a deep coastal sedimentary site in the English Channel, and the surrounding shoreline of Plymouth, UK. The eDNA sequencing indicated that detritus from most macroalgae in surrounding shores occurs within deep, coastal sediments, with detritus supply reflecting the seasonal ecology of individual species. Bayesian stable isotope mixing modeling [C and N] highlighted its vital role in supporting the deep coastal benthic food web (22–36% of diets), especially when other resources are seasonally low. The magnitude of detritus uptake within the food web and sediments varies seasonally, with an average net sedimentary organic macroalgal carbon sequestration of 8.75 g C·m−2·yr−1. The average net sequestration of particulate organic carbon in sediments is 58.74 g C·m−2·yr−1, the two rates corresponding to 4–5% and 26–37% of those associated with mangroves, salt marshes, and seagrass beds, systems more readily identified as blue carbon habitats. These novel data provide important first estimates that help to contextualize the importance of macroalgal-sedimentary connectivity for deep coastal food webs, and measured fluxes help constrain its role within global blue carbon that can support policy development. At a time when climate change mitigation is at the foreground of environmental policy development, embracing the full potential of the ocean in supporting climate regulation via CO2 sequestration is a necessity.
Paris Agreement, benthos, blue carbon, carbon cycling, climate change, ecosystem connectivity, food web, macrophyte, mitigation, trophic subsidy
0012-9615
1-21
Queirós, Ana Moura
fc5e30f2-4c07-4699-896e-e24b5081f88d
Stephens, Nicholas
f057e9af-eb5e-4af8-b9c9-16bdb839771a
Widdicombe, Stephen
3ecf2b3e-6b3f-4f2f-86c5-baf070e8c82b
Tait, Karen
65efb5fa-8898-495d-985d-2f6fec9f7a4c
McCoy, Sophie J.
fc6d991b-16bb-4c5b-9619-27c9005f26c0
Ingels, Jeroen
5dbcfa51-def6-499e-b322-7d8709e3a672
Rühl, Saskia
725215f8-08a4-4fb8-8284-2d6b3efd75cb
Airs, Ruth
e12cc56f-75bc-48d7-b3fd-3e79475620fe
Beesley, Amanda
a5cee2ba-f61b-41a5-a72b-5b97fff5f7c7
Carnovale, Giorgia
f17b1ce7-8240-4236-bf5b-d71d0d0da44b
Cazenave, Pierre
263ea702-1efa-41ac-bcbc-68194faa82d3
Dashfield, Sarah
48418ad4-9b61-4639-a73b-99a5c7406e6e
Hua, Er
671e7f54-096b-4cd2-9a6e-d161137842ad
Jones, Mark
47129f15-3f9e-44ac-add6-b98c4675ba10
Lindeque, Penelope
13334439-fed2-43e0-9c21-3df94d69f963
McNeill, Caroline L.
97e8be9c-045d-46f2-8ace-04684df32455
Nunes, Joana
45dc4c3d-cd31-4ae1-b67e-4469f53405df
Parry, Helen
cd477b11-3c4d-4f0b-8773-053abe6fed64
Pascoe, Christine
47e38ee5-889c-42e7-a620-244034180c10
Widdicombe, Claire
43b3ea18-b072-4f05-bda8-58a79aaf82ce
Smyth, Tim
391b980f-9798-44a8-a0ef-73a730e777c0
Atkinson, Angus
77d9c544-2749-46fe-b991-df2a11d1d6be
Krause-Jensen, Dorte
88375b29-3871-47bd-b425-a66505844784
Somerfield, Paul J.
0ca047e9-0757-49b3-b527-4e9c9ec22f93
Queirós, Ana Moura
fc5e30f2-4c07-4699-896e-e24b5081f88d
Stephens, Nicholas
f057e9af-eb5e-4af8-b9c9-16bdb839771a
Widdicombe, Stephen
3ecf2b3e-6b3f-4f2f-86c5-baf070e8c82b
Tait, Karen
65efb5fa-8898-495d-985d-2f6fec9f7a4c
McCoy, Sophie J.
fc6d991b-16bb-4c5b-9619-27c9005f26c0
Ingels, Jeroen
5dbcfa51-def6-499e-b322-7d8709e3a672
Rühl, Saskia
725215f8-08a4-4fb8-8284-2d6b3efd75cb
Airs, Ruth
e12cc56f-75bc-48d7-b3fd-3e79475620fe
Beesley, Amanda
a5cee2ba-f61b-41a5-a72b-5b97fff5f7c7
Carnovale, Giorgia
f17b1ce7-8240-4236-bf5b-d71d0d0da44b
Cazenave, Pierre
263ea702-1efa-41ac-bcbc-68194faa82d3
Dashfield, Sarah
48418ad4-9b61-4639-a73b-99a5c7406e6e
Hua, Er
671e7f54-096b-4cd2-9a6e-d161137842ad
Jones, Mark
47129f15-3f9e-44ac-add6-b98c4675ba10
Lindeque, Penelope
13334439-fed2-43e0-9c21-3df94d69f963
McNeill, Caroline L.
97e8be9c-045d-46f2-8ace-04684df32455
Nunes, Joana
45dc4c3d-cd31-4ae1-b67e-4469f53405df
Parry, Helen
cd477b11-3c4d-4f0b-8773-053abe6fed64
Pascoe, Christine
47e38ee5-889c-42e7-a620-244034180c10
Widdicombe, Claire
43b3ea18-b072-4f05-bda8-58a79aaf82ce
Smyth, Tim
391b980f-9798-44a8-a0ef-73a730e777c0
Atkinson, Angus
77d9c544-2749-46fe-b991-df2a11d1d6be
Krause-Jensen, Dorte
88375b29-3871-47bd-b425-a66505844784
Somerfield, Paul J.
0ca047e9-0757-49b3-b527-4e9c9ec22f93

Queirós, Ana Moura, Stephens, Nicholas, Widdicombe, Stephen, Tait, Karen, McCoy, Sophie J., Ingels, Jeroen, Rühl, Saskia, Airs, Ruth, Beesley, Amanda, Carnovale, Giorgia, Cazenave, Pierre, Dashfield, Sarah, Hua, Er, Jones, Mark, Lindeque, Penelope, McNeill, Caroline L., Nunes, Joana, Parry, Helen, Pascoe, Christine, Widdicombe, Claire, Smyth, Tim, Atkinson, Angus, Krause-Jensen, Dorte and Somerfield, Paul J. (2019) Connected macroalgal-sediment systems: blue carbon and food webs in the deep coastal ocean. Ecological Monographs, 89 (3), 1-21, [e01366]. (doi:10.1002/ecm.1366).

Record type: Article

Abstract

Macroalgae drive the largest CO2 flux fixed globally by marine macrophytes. Most of the resulting biomass is exported through the coastal ocean as detritus and yet almost no field measurements have verified its potential net sequestration in marine sediments. This gap limits the scope for the inclusion of macroalgae within blue carbon schemes that support ocean carbon sequestration globally, and the understanding of the role their carbon plays within distal food webs. Here, we pursued three lines of evidence (eDNA sequencing, Bayesian Stable Isotope Mixing Modeling, and benthic-pelagic process measurements) to generate needed, novel data addressing this gap. To this end, a 13-month study was undertaken at a deep coastal sedimentary site in the English Channel, and the surrounding shoreline of Plymouth, UK. The eDNA sequencing indicated that detritus from most macroalgae in surrounding shores occurs within deep, coastal sediments, with detritus supply reflecting the seasonal ecology of individual species. Bayesian stable isotope mixing modeling [C and N] highlighted its vital role in supporting the deep coastal benthic food web (22–36% of diets), especially when other resources are seasonally low. The magnitude of detritus uptake within the food web and sediments varies seasonally, with an average net sedimentary organic macroalgal carbon sequestration of 8.75 g C·m−2·yr−1. The average net sequestration of particulate organic carbon in sediments is 58.74 g C·m−2·yr−1, the two rates corresponding to 4–5% and 26–37% of those associated with mangroves, salt marshes, and seagrass beds, systems more readily identified as blue carbon habitats. These novel data provide important first estimates that help to contextualize the importance of macroalgal-sedimentary connectivity for deep coastal food webs, and measured fluxes help constrain its role within global blue carbon that can support policy development. At a time when climate change mitigation is at the foreground of environmental policy development, embracing the full potential of the ocean in supporting climate regulation via CO2 sequestration is a necessity.

This record has no associated files available for download.

More information

Accepted/In Press date: 7 January 2019
e-pub ahead of print date: 23 May 2019
Published date: August 2019
Keywords: Paris Agreement, benthos, blue carbon, carbon cycling, climate change, ecosystem connectivity, food web, macrophyte, mitigation, trophic subsidy

Identifiers

Local EPrints ID: 439561
URI: http://eprints.soton.ac.uk/id/eprint/439561
ISSN: 0012-9615
PURE UUID: 76e9db0f-ee67-4cd7-a237-a7452bf36793
ORCID for Saskia Rühl: ORCID iD orcid.org/0000-0002-4650-6045

Catalogue record

Date deposited: 27 Apr 2020 16:30
Last modified: 25 Nov 2021 18:33

Export record

Altmetrics

Contributors

Author: Ana Moura Queirós
Author: Nicholas Stephens
Author: Stephen Widdicombe
Author: Karen Tait
Author: Sophie J. McCoy
Author: Jeroen Ingels
Author: Saskia Rühl ORCID iD
Author: Ruth Airs
Author: Amanda Beesley
Author: Giorgia Carnovale
Author: Pierre Cazenave
Author: Sarah Dashfield
Author: Er Hua
Author: Mark Jones
Author: Penelope Lindeque
Author: Caroline L. McNeill
Author: Joana Nunes
Author: Helen Parry
Author: Christine Pascoe
Author: Claire Widdicombe
Author: Tim Smyth
Author: Angus Atkinson
Author: Dorte Krause-Jensen
Author: Paul J. Somerfield

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×