Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery
In the Antarctic Peninsula, during the chick-rearing period Adelie (Pygoscelis adeliae) and gentoo (P. papua) penguins feed primarily on Antarctic krill (Euphausia superba), which is also exploited by the commercial fishery. Krill length and proportion of juvenile krill consumed by these predators t...
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ftunivlaplata:oai:sedici.unlp.edu.ar:10915/132482 2023-05-15T14:01:55+02:00 Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery Juáres, Mariana Alejandra Grech, Marta Gladys Casaux, Ricardo Jorge Negrete, Javier Fógel, Jazmín Coria, Néstor Rubén Santos, María Mercedes 2021 application/pdf http://sedici.unlp.edu.ar/handle/10915/132482 en eng http://sedici.unlp.edu.ar/handle/10915/132482 issn:0025-3162 issn:1432-1793 http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) CC-BY-NC-SA Biología Pygoscelis adeliae Pygoscelis papua SISO database Euphausia superba Articulo 2021 ftunivlaplata 2022-03-27T01:06:25Z In the Antarctic Peninsula, during the chick-rearing period Adelie (Pygoscelis adeliae) and gentoo (P. papua) penguins feed primarily on Antarctic krill (Euphausia superba), which is also exploited by the commercial fishery. Krill length and proportion of juvenile krill consumed by these predators that breed at Stranger Point, South Shetland Islands (from 2007/2008 to 2015/2016), and those collected by the krill fishery in the Mar de la Flota/Bransfield Strait (from 2009/2010 to 2015/2016) were compared to evaluate the potential of each data source as an indicator of changes in the size composition and so, in the demographic structure of the krill population. Overall, the mean krill size taken by gentoo penguins was larger than that ingested by Adelie penguins, which consumed higher proportions of juvenile (≤ 35 mm) and one-year-old (≤ 25 mm) krill. Although the krill size caught by the fishery was statistically similar to that taken by both penguin species, there were differences in the frequency distributions of krill size among the three databases. Furthermore, when only adult krill (> 35 mm) was considered, the three sources of krill data showed a similar inter-annual variation in the availability of adult krill cohorts. Our findings suggest that each database analysed here can potentially provide different information (although complementary) about krill size composition. In addition, inter-annual fluctuations in the smaller size classes of krill likely reflect their first year of recruitment and, therefore, may be used as an indicator of shifts in local krill availability. Facultad de Ciencias Naturales y Museo Facultad de Ciencias Exactas Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Antarctic Peninsula Bransfield Strait Euphausia superba Pygoscelis adeliae Pygoscelis papua South Shetland Islands Universidad Nacional de La Plata (UNLP): SeDiCI (Servicio de Difusión de la Creación Intelectual) Antarctic Antarctic Peninsula Bransfield Strait Flota ENVELOPE(-59.000,-59.000,-63.000,-63.000) mar de la Flota ENVELOPE(-59.000,-59.000,-63.000,-63.000) South Shetland Islands Stranger Point ENVELOPE(-58.618,-58.618,-62.262,-62.262) The Antarctic |
institution |
Open Polar |
collection |
Universidad Nacional de La Plata (UNLP): SeDiCI (Servicio de Difusión de la Creación Intelectual) |
op_collection_id |
ftunivlaplata |
language |
English |
topic |
Biología Pygoscelis adeliae Pygoscelis papua SISO database Euphausia superba |
spellingShingle |
Biología Pygoscelis adeliae Pygoscelis papua SISO database Euphausia superba Juáres, Mariana Alejandra Grech, Marta Gladys Casaux, Ricardo Jorge Negrete, Javier Fógel, Jazmín Coria, Néstor Rubén Santos, María Mercedes Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery |
topic_facet |
Biología Pygoscelis adeliae Pygoscelis papua SISO database Euphausia superba |
description |
In the Antarctic Peninsula, during the chick-rearing period Adelie (Pygoscelis adeliae) and gentoo (P. papua) penguins feed primarily on Antarctic krill (Euphausia superba), which is also exploited by the commercial fishery. Krill length and proportion of juvenile krill consumed by these predators that breed at Stranger Point, South Shetland Islands (from 2007/2008 to 2015/2016), and those collected by the krill fishery in the Mar de la Flota/Bransfield Strait (from 2009/2010 to 2015/2016) were compared to evaluate the potential of each data source as an indicator of changes in the size composition and so, in the demographic structure of the krill population. Overall, the mean krill size taken by gentoo penguins was larger than that ingested by Adelie penguins, which consumed higher proportions of juvenile (≤ 35 mm) and one-year-old (≤ 25 mm) krill. Although the krill size caught by the fishery was statistically similar to that taken by both penguin species, there were differences in the frequency distributions of krill size among the three databases. Furthermore, when only adult krill (> 35 mm) was considered, the three sources of krill data showed a similar inter-annual variation in the availability of adult krill cohorts. Our findings suggest that each database analysed here can potentially provide different information (although complementary) about krill size composition. In addition, inter-annual fluctuations in the smaller size classes of krill likely reflect their first year of recruitment and, therefore, may be used as an indicator of shifts in local krill availability. Facultad de Ciencias Naturales y Museo Facultad de Ciencias Exactas |
format |
Article in Journal/Newspaper |
author |
Juáres, Mariana Alejandra Grech, Marta Gladys Casaux, Ricardo Jorge Negrete, Javier Fógel, Jazmín Coria, Néstor Rubén Santos, María Mercedes |
author_facet |
Juáres, Mariana Alejandra Grech, Marta Gladys Casaux, Ricardo Jorge Negrete, Javier Fógel, Jazmín Coria, Néstor Rubén Santos, María Mercedes |
author_sort |
Juáres, Mariana Alejandra |
title |
Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery |
title_short |
Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery |
title_full |
Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery |
title_fullStr |
Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery |
title_full_unstemmed |
Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery |
title_sort |
size structure of antarctic krill inferred from samples of pygoscelid penguin diets and those collected by the commercial krill fishery |
publishDate |
2021 |
url |
http://sedici.unlp.edu.ar/handle/10915/132482 |
long_lat |
ENVELOPE(-59.000,-59.000,-63.000,-63.000) ENVELOPE(-59.000,-59.000,-63.000,-63.000) ENVELOPE(-58.618,-58.618,-62.262,-62.262) |
geographic |
Antarctic Antarctic Peninsula Bransfield Strait Flota mar de la Flota South Shetland Islands Stranger Point The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Bransfield Strait Flota mar de la Flota South Shetland Islands Stranger Point The Antarctic |
genre |
Antarc* Antarctic Antarctic Krill Antarctic Peninsula Bransfield Strait Euphausia superba Pygoscelis adeliae Pygoscelis papua South Shetland Islands |
genre_facet |
Antarc* Antarctic Antarctic Krill Antarctic Peninsula Bransfield Strait Euphausia superba Pygoscelis adeliae Pygoscelis papua South Shetland Islands |
op_relation |
http://sedici.unlp.edu.ar/handle/10915/132482 issn:0025-3162 issn:1432-1793 |
op_rights |
http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
op_rightsnorm |
CC-BY-NC-SA |
_version_ |
1766271990997450752 |