Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis
The biomass size structure of pelagic communities provides a system level perspective that can be instructive when considering trophic interactions. Such perspectives can become even more powerful when combined with taxonomic information and stableisotopeanalysis. Here we apply these approaches to t...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2012
|
Subjects: | |
Online Access: | http://eprints.gla.ac.uk/67515/ |
id |
ftuglasgow:oai:eprints.gla.ac.uk:67515 |
---|---|
record_format |
openpolar |
spelling |
ftuglasgow:oai:eprints.gla.ac.uk:67515 2023-05-15T18:16:01+02:00 Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis Tarling, G.A. Stowasser, G. Ward, P. Venables, H.J. McGill, R.A.R. Murphy, E.J. 2012-01 http://eprints.gla.ac.uk/67515/ unknown Tarling, G.A., Stowasser, G., Ward, P., Venables, H.J., McGill, R.A.R. <http://eprints.gla.ac.uk/view/author/10394.html> and Murphy, E.J. (2012) Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis. Deep-Sea Research Part II: Topical Studies in Oceanography <http://eprints.gla.ac.uk/view/journal_volume/Deep-Sea_Research_Part_II=3A_Topical_Studies_in_Oceanography.html>, 59-60, pp. 222-236. (doi:10.1016/j.dsr2.2011.07.002 <http://dx.doi.org/10.1016/j.dsr2.2011.07.002>) Articles PeerReviewed 2012 ftuglasgow https://doi.org/10.1016/j.dsr2.2011.07.002 2021-09-23T22:45:47Z The biomass size structure of pelagic communities provides a system level perspective that can be instructive when considering trophic interactions. Such perspectives can become even more powerful when combined with taxonomic information and stableisotopeanalysis. Here we apply these approaches to the pelagic community of the ScotiaSea (Southern Ocean) and consider the structure and development of trophic interactions over different years and seasons. Samples were collected from three open-ocean cruises during the austral spring 2006, summer 2008 and autumn 2009. Three main sampling techniques were employed: sampling bottles for microplankton (0–50 m), vertically hauled fine meshed nets for mesozooplankton (0–400 m) and coarse-meshed trawls for macrozooplankton and nekton (0–1000 m). All samples were identified to the lowest practicable taxonomic level and their abundance, individual body weight and biomass (in terms of carbon) estimated. Slopes of normalised biomassspectrum versus size showed a significant but not substantial difference between cruises and were between −1.09 and −1.06. These slopes were shallower than expected for a community at equilibrium and indicated that there was an accumulation of biomass in the larger size classes (101–105 mg C ind−1). A secondary structure of biomass domes was also apparent, with the domes being 2.5–3 log10 intervals apart in spring and summer and 2 log10 intervals apart in autumn. The recruitment of copepod-consuming macrozooplankton, Euphausia triacantha and Themisto gaudichaudii into an additional biomass dome was responsible for the decrease in the inter-dome interval in autumn. Predator to prey mass ratios estimated from stableisotopeanalysis reached a minimum in autumn while the estimated trophic level of myctophid fish was highest in that season. This reflected greater amounts of internal recycling and increased numbers of trophic levels in autumn compared to earlier times of the year. The accumulation of biomass in larger size classes throughout the year in the ScotiaSea may reflect the prevalence of species that store energy and have multiy Article in Journal/Newspaper Scotia Sea Southern Ocean University of Glasgow: Enlighten - Publications Southern Ocean Austral Scotia Sea Deep Sea Research Part II: Topical Studies in Oceanography 59-60 222 236 |
institution |
Open Polar |
collection |
University of Glasgow: Enlighten - Publications |
op_collection_id |
ftuglasgow |
language |
unknown |
description |
The biomass size structure of pelagic communities provides a system level perspective that can be instructive when considering trophic interactions. Such perspectives can become even more powerful when combined with taxonomic information and stableisotopeanalysis. Here we apply these approaches to the pelagic community of the ScotiaSea (Southern Ocean) and consider the structure and development of trophic interactions over different years and seasons. Samples were collected from three open-ocean cruises during the austral spring 2006, summer 2008 and autumn 2009. Three main sampling techniques were employed: sampling bottles for microplankton (0–50 m), vertically hauled fine meshed nets for mesozooplankton (0–400 m) and coarse-meshed trawls for macrozooplankton and nekton (0–1000 m). All samples were identified to the lowest practicable taxonomic level and their abundance, individual body weight and biomass (in terms of carbon) estimated. Slopes of normalised biomassspectrum versus size showed a significant but not substantial difference between cruises and were between −1.09 and −1.06. These slopes were shallower than expected for a community at equilibrium and indicated that there was an accumulation of biomass in the larger size classes (101–105 mg C ind−1). A secondary structure of biomass domes was also apparent, with the domes being 2.5–3 log10 intervals apart in spring and summer and 2 log10 intervals apart in autumn. The recruitment of copepod-consuming macrozooplankton, Euphausia triacantha and Themisto gaudichaudii into an additional biomass dome was responsible for the decrease in the inter-dome interval in autumn. Predator to prey mass ratios estimated from stableisotopeanalysis reached a minimum in autumn while the estimated trophic level of myctophid fish was highest in that season. This reflected greater amounts of internal recycling and increased numbers of trophic levels in autumn compared to earlier times of the year. The accumulation of biomass in larger size classes throughout the year in the ScotiaSea may reflect the prevalence of species that store energy and have multiy |
format |
Article in Journal/Newspaper |
author |
Tarling, G.A. Stowasser, G. Ward, P. Venables, H.J. McGill, R.A.R. Murphy, E.J. |
spellingShingle |
Tarling, G.A. Stowasser, G. Ward, P. Venables, H.J. McGill, R.A.R. Murphy, E.J. Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis |
author_facet |
Tarling, G.A. Stowasser, G. Ward, P. Venables, H.J. McGill, R.A.R. Murphy, E.J. |
author_sort |
Tarling, G.A. |
title |
Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis |
title_short |
Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis |
title_full |
Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis |
title_fullStr |
Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis |
title_full_unstemmed |
Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis |
title_sort |
seasonal trophic structure of the scotia sea pelagic ecosystem considered through biomass spectra and stable isotope analysis |
publishDate |
2012 |
url |
http://eprints.gla.ac.uk/67515/ |
geographic |
Southern Ocean Austral Scotia Sea |
geographic_facet |
Southern Ocean Austral Scotia Sea |
genre |
Scotia Sea Southern Ocean |
genre_facet |
Scotia Sea Southern Ocean |
op_relation |
Tarling, G.A., Stowasser, G., Ward, P., Venables, H.J., McGill, R.A.R. <http://eprints.gla.ac.uk/view/author/10394.html> and Murphy, E.J. (2012) Seasonal trophic structure of the Scotia Sea pelagic ecosystem considered through biomass spectra and stable isotope analysis. Deep-Sea Research Part II: Topical Studies in Oceanography <http://eprints.gla.ac.uk/view/journal_volume/Deep-Sea_Research_Part_II=3A_Topical_Studies_in_Oceanography.html>, 59-60, pp. 222-236. (doi:10.1016/j.dsr2.2011.07.002 <http://dx.doi.org/10.1016/j.dsr2.2011.07.002>) |
op_doi |
https://doi.org/10.1016/j.dsr2.2011.07.002 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
59-60 |
container_start_page |
222 |
op_container_end_page |
236 |
_version_ |
1766189429590851584 |