Lake size, macrophytes, and omnivory contribute to food web linkage in temperate shallow eutrophic lakes

GONZÁLEZ SAGRARIO, M. A.; RODRÍGUEZ GOLPE, D.; LA SALA, L.; SÁNCHEZ VUICHARD, G.; MINOTTI, P.; PANARELLO, H. O.

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2018

0018-8158

Physical, chemical and biological processesfacilitate cross-habitat connections in lakes,prompting food webs to be supported by differentsubsidies. We tested the hypothesis that the pelagicfood web is subsidized by littoral resources and fishforaging behaviour plays a major role in carbon fluxand on food web structure in shallow hypereutrophiclakes. We performed a fish diet and carbon andnitrogen isotope analyses to predict the linkagebetween littoral and pelagic habitats in three shallowhypereutrophic lakes. Lakes differed in morphology,fetch, macrophyte composition and width of thelittoral zone. d13C signals of seston differed amonglakes, but were similar to other producers.Macroinvertebrates and fish carbon signatures weremore enriched in the lake co-dominated by emergentand submerged vegetation. Fish foraging behaviourindicates that more than the 80% of the carbon thatsustain adult fish was channelled from the littoral. Inconclusion, littoral carbon were relevant and sustain,in part, food web in these shallow lakes. Factors likethe extension of the littoral zone, lake morphometry,and the dominance of multi-chain omnivorous fishfacilitate the connection among lake compartmentsand the transference of littoral carbon to lake foodweb.