http://www.cnr.it/ontology/cnr/individuo/prodotto/ID203820

Seasonal changes in the delta C-13 and delta N-15 signatures of the Lago Maggiore pelagic food web (Articolo in rivista)

Type

Articolo in rivista (Classe)
Prodotto della ricerca (Classe)

Label

Seasonal changes in the delta C-13 and delta N-15 signatures of the Lago Maggiore pelagic food web (Articolo in rivista) (literal)

Anno

2011-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.3274/JL11-70-2-14 (literal)

Alternative label

Visconti, A (Visconti, Anna)[ 1 ] ; Manca, M (Manca, Marina)[ 1 ] (2011)
Seasonal changes in the delta C-13 and delta N-15 signatures of the Lago Maggiore pelagic food web
in Journal of limnology (Testo stamp.)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

Visconti, A (Visconti, Anna)[ 1 ] ; Manca, M (Manca, Marina)[ 1 ] (literal)

Pagina inizio

263 (literal)

Pagina fine

271 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#altreInformazioni

ID_PUMA : cnr.ise/2011-A0-034 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

70 (literal)

Rivista

Journal of limnology (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo

2 (literal)

Note

ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

[ 1 ] CNR Inst Ecosyst Study, I-28922 Verbania, Italy (literal)

Titolo

Seasonal changes in the delta C-13 and delta N-15 signatures of the Lago Maggiore pelagic food web (literal)

Abstract

Seasonal variation in the relative contributions of littoral and pelagic food sources to the diets of open-water zooplankton and subsequent changes in their trophic positions were investigated with carbon and nitrogen Stable Isotope Analysis (SIA). We selected three open water stations as truly pelagic. but also influenced by littoral and riverine carbon sources. During each of the four seasons, integrated pelagic zooplankton samples were collected over 0-50 m depth intervals at each site along with seston in the size range 1.2-76 mu m. In addition, vertical temperature profiles were measured. Littoral benthos from three sites along the main longitudinal axis of the lake was sampled to serve as a reference for tracing Lago Maggiores littoral carbon isotopic signature. Among stations differences in delta C-13 and delta N-15 signatures of the different components of the pelagic food web, from seston to predatory zooplankton, were statistically non significant, thus confirming that allochthonous input may become important only after exceptional rainfall events. Changes in the delta C-13 pelagic baseline mirrored Mean water temperature (0-50 m) seasonal changes. Similarly to Lake Geneva, they were likely driven by changes in carbon sources for phytoplankton growth during stratification and vertical water mixing. Differently from what observed fir the other taxa, the role of littoral food sources was far from negligible (>50%) for diaptomids during winter and spring. We do not know however, whether such a result could be at least partially attributed to the heavy infestation by algal epibionts. or was consequent to the fact that these zooplankters may carry littoral carbon to the pelagial via horizontal migration. In winter, Bythotrephes longimanus was able to prey on Cyclops, thus occupying a trophic position comparable to that of planktivorous fish. Such a result confirms an ability of this visual, invertebrate predator to compete with young zooplanktivorous fish for food resources, similarly to what observed in lakes it recently invaded. (literal)

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