Carbon flow and trophic structure of an Antarctic coastal benthic community as determined by δ13C and δ15N

Stable isotopes of carbon and nitrogen were used to determine the different carbon pathways and trophic assemblages amongst coastal benthic fauna of the Windmill Islands, East Antarctica. Macroalgae, pelagic POM, sediment POM and sea ice POM had well-separated δ13C signatures, which ranged from −36....

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Bibliographic Details
Published in:Estuarine, Coastal and Shelf Science
Main Authors: Gillies, Christopher L, Stark, Jonathan S, Johnstone, Glenn J, Smith, Stephen DA
Format: Article in Journal/Newspaper
Language:unknown
Published: ePublications@SCU 2012
Subjects:
Stable isotope analysis
benthic
trophic ecology
Antarctica
Windmill Islands
Casey Station
Environmental Sciences
Antarctic
East Antarctica
Antarc*
Sea ice
Online Access:https://epubs.scu.edu.au/esm_pubs/1303
https://doi.org/10.1016/j.ecss.2011.11.003
Description
Summary:Stable isotopes of carbon and nitrogen were used to determine the different carbon pathways and trophic assemblages amongst coastal benthic fauna of the Windmill Islands, East Antarctica. Macroalgae, pelagic POM, sediment POM and sea ice POM had well-separated δ13C signatures, which ranged from −36.75‰ for the red alga Phyllophora antarctica, to −10.35‰ for sea ice POM. Consumers were also well separated by δ13C, ranging from −21.42‰ for the holothurian Staurocucumis sp. up to −7.47‰ for the urchin Sterechinus neumayeri. Analysis of δ13C and δ15N revealed distinct groups for suspension feeders, grazer/herbivores and deposit feeders, whilst predators and predator/scavengers showed less grouping. Consumers spanned a δ15N range of 8.71‰, equivalent to four trophic levels, although δ15N ratios amongst consumers were continuous, rather than grouped into discrete trophic levels. The study has built a trophic model for the Windmill Islands and summarises three main carbon pathways utilised by the benthos: (1) pelagic POM; (2) macroalgae/epiphytic/benthic diatoms and (3) sediment POM/benthic diatoms. The movement of carbon within the coastal benthic community of the Windmill Islands is considered complex, and stable isotopes of carbon and nitrogen were valuable tools in determining specific feeding guilds and in tracing carbon flow, particularly amongst lower-order consumers.

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