Indexed in

License and use

Citations

Altmetrics

Grant support

This work was supported by grant CGL2005-06549-C02-02/ANT to AC, funded by the Spanish Ministry of Education and Science with European FEDER funds. Latest work by AQ was additionally supported by project PID2020-116520RB-100. We are very grateful for the logistic help and support from the UTM-CSIC and from the Las Palmas crew (Armada Espanola) that made possible this expedition.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was funded by Spanish Ministry of Education and Science (Grant No.: CGL2005-06549-C02-02/ANT), and partly co-funded by Agencia Estatal de Investigacion (Grant No.: PID2020-116520RB-100)

Analysis of institutional authors

Share

Top-down vs. bottom-up effects on the planktonic microbial food web of a maritime Antarctic lake

Publicated to:POLAR BIOLOGY 48 (3): 78- - 2025-09-01 48(3), DOI: 10.1007/s00300-025-03391-9

Authors: Camacho, Antonio; Rochera, Carlos; Rico, Eugenio; Fernandez-Valiente, Eduardo; Vincent, Warwick F; Quesada, Antonio

Affiliations

Abstract

This study evaluated the influence of nutrient (bottom-up) and biological (top-down) controls on the planktonic microbial food web of Lake Limnopolar, an oligotrophic lake in maritime Antarctica. Using a factorial experiment, we manipulated nutrient levels (nitrogen and phosphorus) and macrozooplankton abundance (absence/presence, and abundance increased by 30x) to simulate environmental variations. Nutrient additions led to moderate phytoplankton growth in the absence of zooplankton, indicating nutrient limitation. The presence of zooplankton enhanced algal growth, favoured chlorophytes over diatoms, and significantly increased bacterial abundance while reducing particularly ciliates. These results indicate a cascading effect typical of biological control and they highlight the role of biotic interactions, even in extreme environments where abiotic factors are thought to dominate. Understanding biological controls in such extreme environments is essential, as it underscores the complexity of ecosystem functioning in the polar regions, which are increasingly seen as early indicators of global change.

Keywords