Glacial clay affects foraging performance in a Patagonian fish and cladoceran.

JÖNSSON, M., ; RANÅKER, L.; NICOLLE, A.; LJUNGBERG, P; FAGERBERG, T.; HYLANDER, S.; JEPHSON, T; LEBRET, K.; VON EINEM, J.; HANSSON, L-A.; NILSSON, A.; BALSEIRO, E.G; MODENUTTI, B.E.

HYDROBIOLOGIA

SPRINGER

Año: 2011 vol. 663 p. 101 - 108

0018-8158

Abstract Climate change is altering temperaturesand precipitation patterns all over the world. InPatagonia, Argentina, predicted increase in precipitationtogether with rapidly melting glaciers increase thesurface runoff, and thereby the transport of suspendedsolids to recipient lakes. Suspended solids affect thevisual conditions in the water which in turn restrictsvisual foraging. The native fish Aplochiton zebraJenyns, and its filter-feeding cladoceran prey, Daphniacommutata Ekman, were subjected to foraging experimentsat three turbidity levels. A. zebra foraging ratewas substantially reduced at naturally occurringturbidity levels and the filtering rate of D. commutatawas reduced at the highest turbidity level. Thisindicates that Daphnia may be partly released frompredation from A. zebra at the same time as it canmaintain relatively high feeding rates as turbidityincreases. Lower foraging rates at the same time as themetabolic demand increases, through increased temperatures,may result in larger effects on A. zebra thancould be expected from increases in turbidity ortemperature alone. Turbidity may, as an indirect effectof climate change, decrease planktivore foraging ratesand thereby alter