| Abstract | Shallow lakes are vulnerable ecosystems impacted by human activities and climate change. The Cladocera occupy a central role in food webs and are an excellent paleoecological indicator of food web structure and trophic status. We conducted a paleolimnological study in Lake Blanca Chica (Argentina) to detect changes on the planktivory and herbivory regimes over the last 250 years. Generalized additive models were fitted to the time series of fish predation indicators (ephippial abundance and size, mucrone size, fish scales, and the planktivory index) and pheophorbide a concentration. The cladoceran assemblage changed from littoral-benthic to pelagic species dominance and zooplankton switched from large-bodied (Daphnia) to small-bodied grazers (Bosmina) ca. 1900 due to increased predation. The shift in planktivory regime (ca. 1920-1930), indicated by fish scales and the planktivory index, as well as herbivory (ca. 1920-1950), was triggered by eutrophication. Changes in planktivory affected the size structure of Bosmina, reducing its body size. This study describes the baseline for the lake as well as the profound changes in the composition and size structure of the zooplankton community due to increased predation and the shift in the planktivory regime. These findings will provide a reference status for future management strategies of this ecosystem. |
| Text | 425646 2020 10.3390/w12020597 ISI Web of Science WOS 000519846500288 Scopus 2 s2.0 85081314617 Daphnia Bosmina pheophorbide a fish predation grazing ephippia cladocera sub fossil remains Changes in Planktivory and Herbivory Regimes in a Shallow South American Lake Lake Blanca Chica, Argentina Over the Last 250 Years Carrozzo, David; Musazzi Simona; Lami, Andrea; Cordoba, Francisco E.; Gonzalez Sagrario, Maria de los Angeles Departamento de Biologia, Universidad Nacional de Mar del Plata, J. B. Justo 2550, Mar del Plata, 7600, Argentina National Research Council CNR ,WaterResearchInstitute IRSA , Largo Tonolli50, Verbania, 28922, Italy Instituto de Ecorregiones Andinas INECOA, CONICET UNJu , Instituto de Geologia y Mineria, Universidad Nacional de Jujuy, Av. Bolivia 1661, San Salvador de Jujuy, Y4600GNE, Argentina Instituto de Investigaciones Marinas y Costeras IIMYC , Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CONICET, J. B. Justo 2550, Mar del Plata, 7600, Argentina Shallow lakes are vulnerable ecosystems impacted by human activities and climate change. The Cladocera occupy a central role in food webs and are an excellent paleoecological indicator of food web structure and trophic status. We conducted a paleolimnological study in Lake Blanca Chica Argentina to detect changes on the planktivory and herbivory regimes over the last 250 years. Generalized additive models were fitted to the time series of fish predation indicators ephippial abundance and size, mucrone size, fish scales, and the planktivory index and pheophorbide a concentration. The cladoceran assemblage changed from littoral benthic to pelagic species dominance and zooplankton switched from large bodied Daphnia to small bodied grazers Bosmina ca. 1900 due to increased predation. The shift in planktivory regime ca. 1920 1930 , indicated by fish scales and the planktivory index, as well as herbivory ca. 1920 1950 , was triggered by eutrophication. Changes in planktivory affected the size structure of Bosmina, reducing its body size. This study describes the baseline for the lake as well as the profound changes in the composition and size structure of the zooplankton community due to increased predation and the shift in the planktivory regime. These findings will provide a reference status for future management strategies of this ecosystem. 12 Published version articolo versione pdf water 12 00597.pdf Articolo in rivista Molecular Diversity Preservation International 2073 4441 Water Basel Water Basel Water Basel Water. Basel andrea.lami LAMI ANDREA simona.musazzi MUSAZZI SIMONA SAC.AD002.001.009 ARGENTINA CONICET 094.000 |
