Glacier melting and stoichiometric implications for lake community structure: zooplankton species distributions across a natural light gradient

Authors
Laspoumaderes, Cecilia; Modenutti, Beatriz Estela; Souza, María Sol; Bastidas Navarro, Marcela Alejandra; Cuassolo, Florencia; Balseiro, Esteban Gabriel
Publication Year
2013
Language
English
Format
article
Status
Published version
Description
Glaciers around the globe are melting rapidly, threatening the receiving environments of the world´s fresh water reservoirs with significant changes. The meltwater, carried by rivers, contains large amounts of suspended sediment particles, producing longitudinal gradients in the receiving lakes. These gradients may result in changes in the light : nutrient ratio that affect grazer performance by altering elemental food quality. Thus, glacial melting may induce a shift in the phytoplankton carbon : nutrient ratio and hence influence the dominance of herbivorous zooplankton through stoichiometric mechanisms. To test this hypothesis, we combined field and experimental data, taking advantage of a natural light intensity gradient caused by glacial clay input in a deep oligotrophic Patagonian lake. Across this gradient, we evaluated the abundances of two consumer taxa with different phosphorus requirements, the copepod Boeckella gracilipes and the cladoceran Daphnia commutata, using a six-station transect along the lake. We found significant differences in light : nutrient ratio and stoichiometric food quality of the seston, together with a switch from dominance of P-rich Daphnia in low carbon : nutrient stations to dominance of low-P copepods in high carbon : nutrient stations. The laboratory experiments confirmed that the difference in the carbon : nutrient ratio across the gradient is sufficient to impair Daphnia growth. The overall patterns are consistent with our prediction that shifts in the environmental light : nutrient ratio as a result of glacial melting would contribute to shifts in the dominance of stoichiometrically contrasting taxa in consumer guilds.
Fil: Laspoumaderes, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina
Fil: Modenutti, Beatriz Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina
Fil: Souza, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina
Fil: Bastidas Navarro, Marcela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina
Fil: Cuassolo, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina
Fil: Balseiro, Esteban Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina
Subject
Boeckella gracilipes
Daphnia commutata
food quality
glacial clay
light : nutrient hypothesis
Phosphorus
receiving environments
turbidity
Ecología
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/6691