The effect of fish stocking on mountain lake plankton communities identified using palaeobiological analyses of bottom sediment cores

Abstract

The artificial introduction of fish into a naturally fishless lake can effectively modify the food web and trophic status of that lake. We observed changes in the zooplankton community after stocking fish in Przedni Staw Polski, an oligotrophic mountain lake in the Tatra Mountains (Poland). Results were compared with observations about a stocked lake that naturally contained fish (Morskie Oko), and with two fishless lakes that served as reference sites. The main change observed in the cladoceran community of Przedni Staw Polski was the elimination of largebodied Daphnia *10 years after stocking fish. The introduction of fish also affected the phytoplankton community and resulted in an increase in diatom species related to higher trophic state, most likely due to the fish-induced alteration of the phosphorus cycle. Moreover, all of the studied lakes have been influenced by global and regional climatic and environmental changes, including intensive tourism and acid deposition. Changes in diatom communities were observed after fish stocking even in the lake with a natural fish population, while the zooplankton did not reflect higher fish density. These findings suggest that the natural balance between fish and phytoplankton was destroyed by fish stocking, and although it caused eutrophication in the lake, the higher fish density did not strongly modify the species composition of Cladocera.

A hidden species becoming visible: biogeography and ecology of Rhynchotalona latens (Cladocera, Anomopoda, Chydoridae)

“…Outside Finland, R. latens fossils have been recorded from oligotrophic lakes in alpine regions of central and eastern Europe (Fig. 1; Van Damme & Nevalainen, 2019); in the Swiss Alps (two lakes, Bigler et al, 2006), northern Italy (Lake Ledro, Milan et al, 2017) and Tatra mountains in Poland (two lakes, Sienkiewicz & Gąsiorowski, 2016). Recently, Sweetman & Sarmaja-Korjonen (2017) found R. latens fossil remains, corresponding to those from Finland, from two lakes in the Canadian Arctic treeline.…”

“…The taxon's Holocene and current affiliation to dystrophic and oligotrophic sites (e.g. Bigler et al, 2006;Nevalainen, 2008;Sienkiewicz & Gąsiorowski, 2016;Nevalainen et al, 2018;Van Damme & Nevalainen, 2019) indicates its preference to limno-climatic and habitat conditions resembling periglacial environments, including semiaquatic wetlands, shallow and lush lake littorals and clear and cold waters. R. latens has clearly a low temperature preference, as it is associated with cold temperatures across Finland (Nevalainen et al, 2013) and also in the north boreal-subarctic transition zone of northern Finnish Lapland (Nevalainen et al, 2018).…”

Spatial distribution of zooplankton in the Kolsaiskie mountain lakes (Kungey Ala Tau, south-east Kazakhstan) and its connection with environment factors

“…Введение аллохтонных видов рыб часто оказывает более сильное воздействие на зоопланктон, чем другие факторы [46]. Неоднократное вселение Onchorynchus mykiss [33] и арктического гольца Salvelinus alpinus (Linnaeus, 1758) [30] привело к существенному изменению в зоопланктоне горных альпийских озер.…”

“…Железо, находясь в повышенных концентрациях, действовало в противоположном направлении и стимулировало укрупнение особей в сообществах. Полученные авторами результаты подтверждают чувствительность горных холодноводных озер к внешним воздействиям, что подчеркивалось и другими исследователями [30,33,34,46].…”

Long term subfossil Cladocera record from the partly varved sediment of Lake Tiefer See (NE Germany)

“…In Poland, subfossil Cladocera were analysed mainly in lakes with higher trophic status, from mesotrophic to hypertrophic, while studies on sediments from deep oligotrophic mountain lakes revealed a practically complete absence of species belonging to the Bosminidae family. Oligotrophic lakes in the Tatra Mountains (Szeroczyńska, 2006;Sienkiewicz and Gąsiorowski, 2016), probably had such a low availability of nutrients during the whole Holocene, that edaphic conditions were almost never suitable for the Bosminidae existence. B. longirostris was found only in the sediment deposited during the modern time.…”