Trophic structure of Southern Ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs
International audience Cephalopods are an important component of Southern Ocean food webs, but aspects of their trophic ecology remain unresolved. Here, we used archived squid (order Teuthida) beaks, collected from stomach contents of predators at Macquarie and Kerguelen Islands, to investigate the...
Published in: | Marine Ecology Progress Series |
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Language: | English |
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Online Access: | https://hal.science/hal-03531227 https://doi.org/10.3354/meps13990 |
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ftunivnantes:oai:HAL:hal-03531227v1 2023-05-15T13:58:56+02:00 Trophic structure of Southern Ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs Woods, Bl Walters, A Hindell, M Revill, At Field, I Mccormack, Sa Cherel, Y Trebilco, R University of Tasmania Hobart, Australia (UTAS) Institute for Marine and Antarctic Studies and Centre for Marine Socioecology CSIRO Oceans and Atmosphere Hobart Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) 2022 https://hal.science/hal-03531227 https://doi.org/10.3354/meps13990 en eng HAL CCSD Inter Research info:eu-repo/semantics/altIdentifier/doi/10.3354/meps13990 hal-03531227 https://hal.science/hal-03531227 doi:10.3354/meps13990 ISSN: 0171-8630 EISSN: 1616-1599 Marine Ecology Progress Series https://hal.science/hal-03531227 Marine Ecology Progress Series, 2022, 685, pp.137-152. ⟨10.3354/meps13990⟩ Allometry Biochemical tracers CSIA-AA Nitrogen Trophic position Cephalopods Antarctic Mesopelagic [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2022 ftunivnantes https://doi.org/10.3354/meps13990 2023-03-08T02:12:47Z International audience Cephalopods are an important component of Southern Ocean food webs, but aspects of their trophic ecology remain unresolved. Here, we used archived squid (order Teuthida) beaks, collected from stomach contents of predators at Macquarie and Kerguelen Islands, to investigate the trophic structure within an assemblage of pelagic squids (Alluroteuthis antarcticus, Filippovia knipovitchi, Gonatus antarcticus, Histioteuthis eltaninae, Martialia hyadesi and Brachioteuthis linkovskyi). We combined bulk nitrogen stable isotopes (δ15Nbulk) with compound-specific isotope analysis of amino acids (CSIA-AA) to estimate the trophic position (TP) of species and to assess isotopic relationships with body size at the species, community, and ocean basin levels. We observed significantly higher mean δ15Nbulk values for species at the Kerguelen Islands compared to conspecifics at Macquarie Island. This result was explained by regional variability in δ15N values of phenylalanine (δ15Nphe) suggesting that predator species were accessing different isotopic baselines at each region. This may highlight the different foraging strategies of both species. The overlap in species TP estimates from CSIA-AA (TPCSIA) between the two communities (Macquarie Island TPCSIA min: 2.3, max: 5.3; Kerguelen Islands TPCSIA min: 2.7, max: 5.3) indicated a similar trophic structure at both locations. We note unrealistically low TPCSIA for some species, which we attribute to uncertainty of trophic discrimination factors. TP estimates suggested that squid encompass three trophic levels from mid-trophic levels to higher predators. We did not find strong or consistent relationships between TP and body size at either the species- or community-level. One of the largest squid species, Martialia hyadesi, occupied the lowest TP in both communities. These new insights into the trophic structure of the Southern Ocean squid community have important implications for the future representation of pelagic squids in ecosystem models. Article in Journal/Newspaper Antarc* Antarctic antarcticus Kerguelen Islands Macquarie Island Southern Ocean Université de Nantes: HAL-UNIV-NANTES Antarctic Kerguelen Kerguelen Islands Southern Ocean Marine Ecology Progress Series 685 137 152 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
Allometry Biochemical tracers CSIA-AA Nitrogen Trophic position Cephalopods Antarctic Mesopelagic [SDE]Environmental Sciences |
spellingShingle |
Allometry Biochemical tracers CSIA-AA Nitrogen Trophic position Cephalopods Antarctic Mesopelagic [SDE]Environmental Sciences Woods, Bl Walters, A Hindell, M Revill, At Field, I Mccormack, Sa Cherel, Y Trebilco, R Trophic structure of Southern Ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs |
topic_facet |
Allometry Biochemical tracers CSIA-AA Nitrogen Trophic position Cephalopods Antarctic Mesopelagic [SDE]Environmental Sciences |
description |
International audience Cephalopods are an important component of Southern Ocean food webs, but aspects of their trophic ecology remain unresolved. Here, we used archived squid (order Teuthida) beaks, collected from stomach contents of predators at Macquarie and Kerguelen Islands, to investigate the trophic structure within an assemblage of pelagic squids (Alluroteuthis antarcticus, Filippovia knipovitchi, Gonatus antarcticus, Histioteuthis eltaninae, Martialia hyadesi and Brachioteuthis linkovskyi). We combined bulk nitrogen stable isotopes (δ15Nbulk) with compound-specific isotope analysis of amino acids (CSIA-AA) to estimate the trophic position (TP) of species and to assess isotopic relationships with body size at the species, community, and ocean basin levels. We observed significantly higher mean δ15Nbulk values for species at the Kerguelen Islands compared to conspecifics at Macquarie Island. This result was explained by regional variability in δ15N values of phenylalanine (δ15Nphe) suggesting that predator species were accessing different isotopic baselines at each region. This may highlight the different foraging strategies of both species. The overlap in species TP estimates from CSIA-AA (TPCSIA) between the two communities (Macquarie Island TPCSIA min: 2.3, max: 5.3; Kerguelen Islands TPCSIA min: 2.7, max: 5.3) indicated a similar trophic structure at both locations. We note unrealistically low TPCSIA for some species, which we attribute to uncertainty of trophic discrimination factors. TP estimates suggested that squid encompass three trophic levels from mid-trophic levels to higher predators. We did not find strong or consistent relationships between TP and body size at either the species- or community-level. One of the largest squid species, Martialia hyadesi, occupied the lowest TP in both communities. These new insights into the trophic structure of the Southern Ocean squid community have important implications for the future representation of pelagic squids in ecosystem models. |
author2 |
University of Tasmania Hobart, Australia (UTAS) Institute for Marine and Antarctic Studies and Centre for Marine Socioecology CSIRO Oceans and Atmosphere Hobart Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) |
format |
Article in Journal/Newspaper |
author |
Woods, Bl Walters, A Hindell, M Revill, At Field, I Mccormack, Sa Cherel, Y Trebilco, R |
author_facet |
Woods, Bl Walters, A Hindell, M Revill, At Field, I Mccormack, Sa Cherel, Y Trebilco, R |
author_sort |
Woods, Bl |
title |
Trophic structure of Southern Ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs |
title_short |
Trophic structure of Southern Ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs |
title_full |
Trophic structure of Southern Ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs |
title_fullStr |
Trophic structure of Southern Ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs |
title_full_unstemmed |
Trophic structure of Southern Ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs |
title_sort |
trophic structure of southern ocean squid: a cross-basin analysis of stable isotopes in archived beaks from predator stomachs |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://hal.science/hal-03531227 https://doi.org/10.3354/meps13990 |
geographic |
Antarctic Kerguelen Kerguelen Islands Southern Ocean |
geographic_facet |
Antarctic Kerguelen Kerguelen Islands Southern Ocean |
genre |
Antarc* Antarctic antarcticus Kerguelen Islands Macquarie Island Southern Ocean |
genre_facet |
Antarc* Antarctic antarcticus Kerguelen Islands Macquarie Island Southern Ocean |
op_source |
ISSN: 0171-8630 EISSN: 1616-1599 Marine Ecology Progress Series https://hal.science/hal-03531227 Marine Ecology Progress Series, 2022, 685, pp.137-152. ⟨10.3354/meps13990⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3354/meps13990 hal-03531227 https://hal.science/hal-03531227 doi:10.3354/meps13990 |
op_doi |
https://doi.org/10.3354/meps13990 |
container_title |
Marine Ecology Progress Series |
container_volume |
685 |
container_start_page |
137 |
op_container_end_page |
152 |
_version_ |
1766267301711052800 |