Trophic relationships among Southern Ocean copepods and krill: Some uses and limitations of a stable isotope approach
The use of stable isotopes to study food webs has increased rapidly, but there are still some uncertainties in their application. We examined the δ 15 N and δ 13 C values of Antarctic euphausiids and copepods from the Polar Front, Lazarev Sea, and Marguerite Bay against their foodweb baseline of par...
Published in: | Limnology and Oceanography |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2003
|
Subjects: | |
Online Access: | http://dx.doi.org/10.4319/lo.2003.48.1.0277 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.2003.48.1.0277 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.2003.48.1.0277 |
id |
crwiley:10.4319/lo.2003.48.1.0277 |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.4319/lo.2003.48.1.0277 2024-06-23T07:46:24+00:00 Trophic relationships among Southern Ocean copepods and krill: Some uses and limitations of a stable isotope approach Schmidt, Katrin Atkinson, Angus Stübing, Dorothea McClelland, James W. Montoya, Joseph P. Voss, Maren 2003 http://dx.doi.org/10.4319/lo.2003.48.1.0277 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.2003.48.1.0277 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.2003.48.1.0277 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Limnology and Oceanography volume 48, issue 1, page 277-289 ISSN 0024-3590 1939-5590 journal-article 2003 crwiley https://doi.org/10.4319/lo.2003.48.1.0277 2024-05-31T08:13:16Z The use of stable isotopes to study food webs has increased rapidly, but there are still some uncertainties in their application. We examined the δ 15 N and δ 13 C values of Antarctic euphausiids and copepods from the Polar Front, Lazarev Sea, and Marguerite Bay against their foodweb baseline of particulate organic matter (POM). Interpretations of trophic level were helped by comparison with other approaches and by calibration experiments with Euphausia superba fed known diets. Results for well‐known mesozooplankters (e.g., Calanoides acutus and Metridia gerlachei ) were internally consistent and corresponded to those derived from independent methods. This gave confidence in the isotope approach for copepods and probably larval euphausiids. Among the dominant yet poorly known species, it suggested mainly herbivory for Rhincalanus gigas but omnivory for Calanus simillimus and furcilia larvae of Thysanoessa spp. and Euphausia frigida . The δ 15 N values of adult copepods were up to 3‰ higher than those of early copepodites, pointing to ontogenetic shifts in diet. In the Lazarev Sea in autumn, the isotopic signals of E. superba larvae suggested pelagic, mainly herbivorous, feeding rather than feeding within the ice. In contrast to the mesozooplankton, some anomalous results for postlarval krill species indicated problems with this method for micronekton. The experiments showed that postlarval E. superba did not equilibriate with a new diet within 30 d. We suggest that the slower turnover of these larger species, partly in combination with their ability to migrate, has confounded trophic effects with those of a temporally/spatially changing food‐web baseline. Interpretations of food sources of micronekton could be helped by analyzing their molts or fecal pellets, which responded faster to a new diet. Article in Journal/Newspaper Antarc* Antarctic Euphausia superba Lazarev Sea Mesozooplankton Southern Ocean Copepods Wiley Online Library Antarctic Lazarev ENVELOPE(12.917,12.917,-69.967,-69.967) Lazarev Sea ENVELOPE(7.000,7.000,-68.000,-68.000) Marguerite ENVELOPE(141.378,141.378,-66.787,-66.787) Marguerite Bay ENVELOPE(-68.000,-68.000,-68.500,-68.500) Southern Ocean Limnology and Oceanography 48 1 277 289 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
The use of stable isotopes to study food webs has increased rapidly, but there are still some uncertainties in their application. We examined the δ 15 N and δ 13 C values of Antarctic euphausiids and copepods from the Polar Front, Lazarev Sea, and Marguerite Bay against their foodweb baseline of particulate organic matter (POM). Interpretations of trophic level were helped by comparison with other approaches and by calibration experiments with Euphausia superba fed known diets. Results for well‐known mesozooplankters (e.g., Calanoides acutus and Metridia gerlachei ) were internally consistent and corresponded to those derived from independent methods. This gave confidence in the isotope approach for copepods and probably larval euphausiids. Among the dominant yet poorly known species, it suggested mainly herbivory for Rhincalanus gigas but omnivory for Calanus simillimus and furcilia larvae of Thysanoessa spp. and Euphausia frigida . The δ 15 N values of adult copepods were up to 3‰ higher than those of early copepodites, pointing to ontogenetic shifts in diet. In the Lazarev Sea in autumn, the isotopic signals of E. superba larvae suggested pelagic, mainly herbivorous, feeding rather than feeding within the ice. In contrast to the mesozooplankton, some anomalous results for postlarval krill species indicated problems with this method for micronekton. The experiments showed that postlarval E. superba did not equilibriate with a new diet within 30 d. We suggest that the slower turnover of these larger species, partly in combination with their ability to migrate, has confounded trophic effects with those of a temporally/spatially changing food‐web baseline. Interpretations of food sources of micronekton could be helped by analyzing their molts or fecal pellets, which responded faster to a new diet. |
format |
Article in Journal/Newspaper |
author |
Schmidt, Katrin Atkinson, Angus Stübing, Dorothea McClelland, James W. Montoya, Joseph P. Voss, Maren |
spellingShingle |
Schmidt, Katrin Atkinson, Angus Stübing, Dorothea McClelland, James W. Montoya, Joseph P. Voss, Maren Trophic relationships among Southern Ocean copepods and krill: Some uses and limitations of a stable isotope approach |
author_facet |
Schmidt, Katrin Atkinson, Angus Stübing, Dorothea McClelland, James W. Montoya, Joseph P. Voss, Maren |
author_sort |
Schmidt, Katrin |
title |
Trophic relationships among Southern Ocean copepods and krill: Some uses and limitations of a stable isotope approach |
title_short |
Trophic relationships among Southern Ocean copepods and krill: Some uses and limitations of a stable isotope approach |
title_full |
Trophic relationships among Southern Ocean copepods and krill: Some uses and limitations of a stable isotope approach |
title_fullStr |
Trophic relationships among Southern Ocean copepods and krill: Some uses and limitations of a stable isotope approach |
title_full_unstemmed |
Trophic relationships among Southern Ocean copepods and krill: Some uses and limitations of a stable isotope approach |
title_sort |
trophic relationships among southern ocean copepods and krill: some uses and limitations of a stable isotope approach |
publisher |
Wiley |
publishDate |
2003 |
url |
http://dx.doi.org/10.4319/lo.2003.48.1.0277 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.2003.48.1.0277 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.2003.48.1.0277 |
long_lat |
ENVELOPE(12.917,12.917,-69.967,-69.967) ENVELOPE(7.000,7.000,-68.000,-68.000) ENVELOPE(141.378,141.378,-66.787,-66.787) ENVELOPE(-68.000,-68.000,-68.500,-68.500) |
geographic |
Antarctic Lazarev Lazarev Sea Marguerite Marguerite Bay Southern Ocean |
geographic_facet |
Antarctic Lazarev Lazarev Sea Marguerite Marguerite Bay Southern Ocean |
genre |
Antarc* Antarctic Euphausia superba Lazarev Sea Mesozooplankton Southern Ocean Copepods |
genre_facet |
Antarc* Antarctic Euphausia superba Lazarev Sea Mesozooplankton Southern Ocean Copepods |
op_source |
Limnology and Oceanography volume 48, issue 1, page 277-289 ISSN 0024-3590 1939-5590 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.4319/lo.2003.48.1.0277 |
container_title |
Limnology and Oceanography |
container_volume |
48 |
container_issue |
1 |
container_start_page |
277 |
op_container_end_page |
289 |
_version_ |
1802645642517938176 |