Paleolimnological evidence of the Inverted Trophic Cascade Hypothesis in a Neotropical lake

In a natural lake of southeastern Brazil (Lake Carioca), the current scarcity of limnetic cladocerans is attributed to the predatory activity of the dipteran Chaoborus larvae. The Inverted Trophic Cascade Hypothesis (ITCH) predicted that such predation pressure intensified after the decrease in nati...

Full description

Saved in:

Bibliographic Details
Published in:	Journal of paleolimnology Vol. 71; no. 2; pp. 139 - 151
Main Authors:	Maroneze, Daniel Marchetti, Menendez, Rosa Maria, Ferreira, Daniela Rabello, Pujoni, Diego Guimarães Florencio, de Lima Ferreira, Paulo Alves, Figueira, Rubens Cesar Lopes, Maia-Barbosa, Paulina Maria
Format:	Journal Article
Language:	English
Published:	Dordrecht Springer Netherlands 01-02-2024 Springer Nature B.V
Subjects:	Animal population Aquaculture Biodiversity Chaoborus Climate Change Earth and Environmental Science Earth Sciences Ecological effects Fish Fish populations Fishing Food chains Food webs Freshwater & Marine Ecology Geology Hypotheses Interspecific relationships Lakes Larvae Lead isotopes Original Paper Paleontology Physical Geography Polyculture (aquaculture) Predation Predators Prey Radiometric dating Sediment samples Sedimentology Sport fishing Trophic levels Wildlife conservation Chaoborus larvae Non-native piscivorous fish Invertebrate predation Bosmina
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	In a natural lake of southeastern Brazil (Lake Carioca), the current scarcity of limnetic cladocerans is attributed to the predatory activity of the dipteran Chaoborus larvae. The Inverted Trophic Cascade Hypothesis (ITCH) predicted that such predation pressure intensified after the decrease in native planktivorous fish populations, due to non-native piscivorous fish introductions. However, the ITCH is mainly based on recent data obtained when the non-native piscivorous fish have already disturbed the community of this Neotropical lake. In the present study, we used a paleolimnological approach aiming to provide evidence in support of ITCH. Specifically, we evaluated: (1) whether a great numerical increase of Chaoborus larvae and a sharp decline in the number of small cladocerans (Bosminidae) occurred in the recent past of Lake Carioca, and (2) whether the Bosmina tubicen size structure changed temporally in response to the dominant predator (from planktivorous fish to Chaoborus larvae). Samples from one sediment core collected in the deepest zone of the lake were concurrently used for radiometric dating, quantification of invertebrate subfossils, and measurement of B. tubicen size attributes. The radiometric dating was based on the analysis of 210 Pb. Although we recorded an evident decline of Bosmina subfossils after the introduction of non-native piscivorous fish, we did not observe an increase of Chaoborus subfossils. Significant increases in the mean lengths of carapaces and mucros of B. tubicen were detected in Lake Carioca after the dominant predation regime changed from planktivorous fish to Chaoborus larvae. Despite the statistical significance, the differences for both attributes exhibited a small effect size and likely had limited ecological implications on the dynamics of local food web. Our results support one of the assumptions of the ITCH; showing that the negative effects of non-native piscivorous fish were not restricted to their prey (native planktivorous fish), but cascaded down, reaching the lower trophic levels (small limnetic cladocerans). This finding has relevant implications for the conservation and management of biodiversity in Neotropical lakes. It reinforces the need to better plan and control activities that historically have contributed to the spread of piscivorous fish outside their original areas such as aquaculture and sport fishing.
ISSN:	0921-2728 1573-0417
DOI:	10.1007/s10933-023-00306-8