Food web structure of a Pantanal shallow lake revealed by stable isotopes
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Food webs are good ecological macro-descriptors and their study is important in ecology in understanding nutrient cycles, tracing and quantifying energy and in describing trophic interactions within an ecosystem. The knowledge of food web finds applications in various natural sciences disciplines but also in many productive sectors. This study investigated the structure of the food web of a shallow lake in the Pantanal flood plain. The food web included two macrophytes, six aquatic insects, four crustaceans and 24 fish species. Sources of carbon for the various organisms living in the lake were identified through the values of δ13C exhibited by the organisms. The δ15N signature was used to estimate the trophic position of each organism. A cluster analysis based on the two isotopic signatures revealed six different feeding guilds and emphasized on the broad occurrence of omnivory among animals living in the lake. This study revealed that the use of food carbon was the most important factor that structured the lake community. Very low values of δ13C in zooplankton, benthic dwellers and bottom-feeder organisms as well as similarities between the gradient of δ13C and that of use of methane oxidizing bacteria informed on the possible use of biogenic methane as a source carbon and energy for the lake biota.
Place, publisher, year, edition, pages
2013. , 36 p.
Cluster analysis, food webs, Pantanal, stable isotopes
IdentifiersURN: urn:nbn:se:liu:diva-97702ISRN: LIU-TEMAV/MPSSD-A-13/012- -SEOAI: oai:DiVA.org:liu-97702DiVA: diva2:650176
Subject / course
Master´s in Science for Sustainable Development
David, Bastviken, Associate professor
Joyanto, Routh, Associate professor