Changing ecology of Lake Victoria cichlids and their environment: evidence from C13 and N15 analyses

van Rijssel, Jacobus Cornelis; Hecky, Robert E.; Kishe-Machumu, Mary A.; Witte, F. (2016). Changing ecology of Lake Victoria cichlids and their environment: evidence from C13 and N15 analyses. Hydrobiologia, 791(1), pp. 175-191. Springer 10.1007/s10750-016-2790-y

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Eutrophication is an increasing global threat to freshwater ecosystems. East Africa’s Lake Victoria has suffered from severe eutrophication in the past decades which is partly responsible for the dramatic decline in haplochromine cichlid species diversity. However, some zooplanktivorous and detritivorous haplochromine species recovered and shifted their diet towards macro invertebrates and fish. We used four formalin preserved cichlid species caught over the past 35 years to investigate whether stable isotopes of these fish are reflecting the dietary changes, habitat differences and if these isotopes can be used as indicators of eutrophication. We found that d15N signatures mainly reflected dietary shifts to larger prey in all four haplochromine species. Shifts in d13C signatures likely represented habitat differences and dietary changes. In addition, a shift to remarkably heavy d13C signatures in 2011 was found for all four species which might infer increased primary production and thus eutrophication although more research is needed to confirm this hypothesis. The observed temporal changes confirm previous findings that preserved specimens can be used to trace historical changes in fish ecology and the aquatic environment. This highlights the need for continued sampling as this information could be of essence for reconstructing and predicting the effects of environmental changes.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE)
08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE) > Aquatic Ecology

UniBE Contributor:

van Rijssel, Jacobus Cornelis

Subjects:

500 Science > 570 Life sciences; biology

ISSN:

0018-8158

Publisher:

Springer

Language:

English

Submitter:

Marcel Häsler

Date Deposited:

08 Jul 2016 15:09

Last Modified:

05 Mar 2017 02:07

Publisher DOI:

10.1007/s10750-016-2790-y

BORIS DOI:

10.7892/boris.82429

URI:

https://boris.unibe.ch/id/eprint/82429

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