Cargando…

Effects of macroalgae loss in an Antarctic marine food web: applying extinction thresholds to food web studies

Antarctica is seriously affected by climate change, particularly at the Western Antarctic Peninsula (WAP) where a rapid regional warming is observed. Potter Cove is a WAP fjord at Shetland Islands that constitutes a biodiversity hotspot where over the last years, Potter Cove annual air temperatures...

Descripción completa

Detalles Bibliográficos
Autores principales: Cordone, Georgina, Marina, Tomás I., Salinas, Vanesa, Doyle, Santiago R., Saravia, Leonardo A., Momo, Fernando R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139014/
https://www.ncbi.nlm.nih.gov/pubmed/30225167
http://dx.doi.org/10.7717/peerj.5531
_version_ 1783355449112788992
author Cordone, Georgina
Marina, Tomás I.
Salinas, Vanesa
Doyle, Santiago R.
Saravia, Leonardo A.
Momo, Fernando R.
author_facet Cordone, Georgina
Marina, Tomás I.
Salinas, Vanesa
Doyle, Santiago R.
Saravia, Leonardo A.
Momo, Fernando R.
author_sort Cordone, Georgina
collection PubMed
description Antarctica is seriously affected by climate change, particularly at the Western Antarctic Peninsula (WAP) where a rapid regional warming is observed. Potter Cove is a WAP fjord at Shetland Islands that constitutes a biodiversity hotspot where over the last years, Potter Cove annual air temperatures averages increased by 0.66 °C, coastal glaciers declined, and suspended particulate matter increased due to ice melting. Macroalgae are the main energy source for all consumers and detritivores of Potter Cove. Some effects of climate change favor pioneer macroalgae species that exploit new ice-free areas and can also decline rates of photosynthesis and intensify competition between species due to the increase of suspended particulate matter. In this study, we evaluated possible consequences of climate change at Potter Cove food web by simulating the extinction of macroalgae and detritus using a topological approach with thresholds of extinction. Thresholds represent the minimum number of incoming links necessary for species’ survival. When we simulated the extinctions of macroalgae species at random, a threshold of extinction beyond 50% was necessary to obtain a significant number of secondary extinctions, while with a 75% threshold a real collapse of the food web occurred. Our results indicate that Potter Cove food web is relative robust to macroalgae extinction. This is dramatically different from what has been found in other food webs, where the reduction of 10% in prey intake caused a disproportionate increase of secondary extinctions. Robustness of the Potter Cove food web was mediated by omnivory and redundancy, which had an important relevance in this food web. When we eliminated larger-biomass species more secondary extinctions occurred, a similar response was observed when more connected species were deleted, yet there was no correlation between species of larger-biomass and high-degree. This similarity could be explained because both criteria involved key species that produced an emerging effect on the food web. In this way, large-biomass and high-degree species could be acting as source for species with few trophic interactions or low redundancy. Based on this work, we expect the Potter Cove food web to be robust to changes in macroalgae species caused by climate change until a high threshold of stress is reached, and then negative effects are expected to spread through the entire food web leading to its collapse.
format Online
Article
Text
id pubmed-6139014
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher PeerJ Inc.
record_format MEDLINE/PubMed
spelling pubmed-61390142018-09-17 Effects of macroalgae loss in an Antarctic marine food web: applying extinction thresholds to food web studies Cordone, Georgina Marina, Tomás I. Salinas, Vanesa Doyle, Santiago R. Saravia, Leonardo A. Momo, Fernando R. PeerJ Ecology Antarctica is seriously affected by climate change, particularly at the Western Antarctic Peninsula (WAP) where a rapid regional warming is observed. Potter Cove is a WAP fjord at Shetland Islands that constitutes a biodiversity hotspot where over the last years, Potter Cove annual air temperatures averages increased by 0.66 °C, coastal glaciers declined, and suspended particulate matter increased due to ice melting. Macroalgae are the main energy source for all consumers and detritivores of Potter Cove. Some effects of climate change favor pioneer macroalgae species that exploit new ice-free areas and can also decline rates of photosynthesis and intensify competition between species due to the increase of suspended particulate matter. In this study, we evaluated possible consequences of climate change at Potter Cove food web by simulating the extinction of macroalgae and detritus using a topological approach with thresholds of extinction. Thresholds represent the minimum number of incoming links necessary for species’ survival. When we simulated the extinctions of macroalgae species at random, a threshold of extinction beyond 50% was necessary to obtain a significant number of secondary extinctions, while with a 75% threshold a real collapse of the food web occurred. Our results indicate that Potter Cove food web is relative robust to macroalgae extinction. This is dramatically different from what has been found in other food webs, where the reduction of 10% in prey intake caused a disproportionate increase of secondary extinctions. Robustness of the Potter Cove food web was mediated by omnivory and redundancy, which had an important relevance in this food web. When we eliminated larger-biomass species more secondary extinctions occurred, a similar response was observed when more connected species were deleted, yet there was no correlation between species of larger-biomass and high-degree. This similarity could be explained because both criteria involved key species that produced an emerging effect on the food web. In this way, large-biomass and high-degree species could be acting as source for species with few trophic interactions or low redundancy. Based on this work, we expect the Potter Cove food web to be robust to changes in macroalgae species caused by climate change until a high threshold of stress is reached, and then negative effects are expected to spread through the entire food web leading to its collapse. PeerJ Inc. 2018-09-12 /pmc/articles/PMC6139014/ /pubmed/30225167 http://dx.doi.org/10.7717/peerj.5531 Text en ©2018 Cordone et al. http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
spellingShingle Ecology
Cordone, Georgina
Marina, Tomás I.
Salinas, Vanesa
Doyle, Santiago R.
Saravia, Leonardo A.
Momo, Fernando R.
Effects of macroalgae loss in an Antarctic marine food web: applying extinction thresholds to food web studies
title Effects of macroalgae loss in an Antarctic marine food web: applying extinction thresholds to food web studies
title_full Effects of macroalgae loss in an Antarctic marine food web: applying extinction thresholds to food web studies
title_fullStr Effects of macroalgae loss in an Antarctic marine food web: applying extinction thresholds to food web studies
title_full_unstemmed Effects of macroalgae loss in an Antarctic marine food web: applying extinction thresholds to food web studies
title_short Effects of macroalgae loss in an Antarctic marine food web: applying extinction thresholds to food web studies
title_sort effects of macroalgae loss in an antarctic marine food web: applying extinction thresholds to food web studies
topic Ecology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139014/
https://www.ncbi.nlm.nih.gov/pubmed/30225167
http://dx.doi.org/10.7717/peerj.5531
work_keys_str_mv AT cordonegeorgina effectsofmacroalgaelossinanantarcticmarinefoodwebapplyingextinctionthresholdstofoodwebstudies
AT marinatomasi effectsofmacroalgaelossinanantarcticmarinefoodwebapplyingextinctionthresholdstofoodwebstudies
AT salinasvanesa effectsofmacroalgaelossinanantarcticmarinefoodwebapplyingextinctionthresholdstofoodwebstudies
AT doylesantiagor effectsofmacroalgaelossinanantarcticmarinefoodwebapplyingextinctionthresholdstofoodwebstudies
AT saravialeonardoa effectsofmacroalgaelossinanantarcticmarinefoodwebapplyingextinctionthresholdstofoodwebstudies
AT momofernandor effectsofmacroalgaelossinanantarcticmarinefoodwebapplyingextinctionthresholdstofoodwebstudies