Water level and fish-mediated cascading effects on the microbial community in eutrophic warm shallow lakes: a mesocosm experiment

Bucak, Tuba
Tavsanoglu, Ulku Nihan
Cakiroglu, Ayse Idil
Levi, Eti Ester
Coppens, Jan
Jeppesen, Erik
Beklioğlu, Meryem
Information on the effects of water level changes on microbial planktonic communities in lakes is limited but vital for understanding ecosystem dynamics in Mediterranean lakes subjected to major intra- and inter-annual variations in water level. We performed an in situ mesocosm experiment in an eutrophic Turkish lake at two different depths crossed with presence/absence of fish in order to explore the effects of water level variations and the role of top-down regulation at contrasting depths. Strong effects of fish were found on zooplankton, weakening through the food chain to ciliates, HNF and bacterioplankton, whereas the effect of water level variations was overall modest. Presence of fish resulted in lower biomass of zooplankton and higher biomasses of phytoplankton, ciliates and total plankton. The cascading effects of fish were strongest in the shallow mesocosms as evidenced by a lower zooplankton contribution to total plankton biomass and lower zooplankton:ciliate and HNF:bacteria biomass ratios. Our results suggest that a lowering of the water level in warm shallow lakes will enhance the contribution of bacteria, HNF and ciliates to the plankton biomass, likely due to increased density of submerged macrophytes (less phytoplankton); this effect will, however, be less pronounced in the presence of fish.


Drought-induced changes in nutrient concentrations and retention in two shallow Mediterranean lakes subjected to different degrees of management
Ozen, Arda; Karapinar, Burcu; Kucuk, Ismail; Jeppesen, Erik; Beklioğlu, Meryem (Springer Science and Business Media LLC, 2010-06-01)
While extensive knowledge exists on the relationship between nutrient loading and nutrient concentrations in lakes in the cold temperate region, few studies have been conducted in warm lakes, not least in warm arid lakes. This is unfortunate as a larger proportion of the world's lakes will be situated in arid climates in the future due to climate change and a larger proportion will suffer from a higher frequency of intensive drought. We conducted a comprehensive 11-13 year mass balance study in two intercon...
Toward predicting climate change effects on lakes: a comparison of 1656 shallow lakes from Florida and Denmark reveals substantial differences in nutrient dynamics, metabolism, trophic structure, and top-down control
Jeppesen, Erik; Canfield, Daniel E.; Bachmann, Roger W.; Sondergaard, Martin; Havens, Karl E.; Johansson, Liselotte S.; Lauridsen, Torben L.; Tserenpil, Sh; Rutter, Robert P.; Warren, Gary; Ji, Gaohua; Hoyer, Mark (Informa UK Limited, 2020-04-01)
Rapid climate changes may potentially have strong impacts on the ecosystem structure and nutrient dynamics of lakes as well as implications for water quality. We used a space-for-time approach to elucidate such possible effects by comparing data from 1656 shallow lakes (mean depth 100 mu g L-1) in the FL lakes, but coverage was higher in the DK lakes at low TP. We also found lower oxygen saturation in the nutrient-rich FL lakes than in the DK lakes, suggesting lower net ecosystem production in the FL lakes....
Water level control over submerged macrophyte development in five shallow lakes of Mediterranean Turkey
Beklioğlu, Meryem; Tan, Can O. (2006-08-01)
The functioning of shallow lakes is supposedly very sensitive to water level fluctuations (WLF). Relationships between WLF and submerged macrophyte development were investigated in five Turkish shallow lakes located in a semi-arid to and Mediterranean climate where the hydrological event of WLF is a common phenomenon. In all lakes, WLF emerged as a major factor determining submerged plant development. High submerged plant coverage was observed in four of the study lakes, Lake Beysehir, Lake Uluabat, Lake Ma...
Restoration of the eutrophic Lake Eymir, Turkey, by biomanipulation after a major external nutrient control I
Beklioğlu, Meryem; Tuzun, I (Springer Science and Business Media LLC, 2003-01-01)
Nutrient loading in lakes is recognized as a serious threat to water quality. Over 25 years of raw sewage effluent discharge shifted Lake Eymir from a state dominated by submerged plants to a turbid water state. Successful effluent diversion undertaken in 1995 achieved 88% and 95% reductions in the areal loading of total phosphorus (TP) and dissolved inorganic nitrogen (DIN), respectively. Furthermore, the reduced load of TP was very close to the suggested threshold areal load (0.6 g m(-2) yr(-1)) to attain...
Effects of waterfowl, large fish and periphyton on the spring growth of Potamogeton pectinatus L. in Lake Mogan, Turkey
Sandsten, H; Beklioğlu, Meryem; Ince, O (Springer Science and Business Media LLC, 2005-03-15)
It has been argued that waterfowl and fish may threaten growth of submerged macrophytes, especially in spring during the early growth phase when plant biomass is low. A small reduction of biomass at that time might delay growth or decrease subsequent productivity. We investigated the impact of waterfowl and large fish on the spring growth of fennel pondweed (Potamogeton pectinatus L.) by employing an exclosure experiment in the macrophyte-dominated clear-water Lake Mogan, Turkey. Birds and large fish were e...
Citation Formats
A. ÖZEN et al., “Water level and fish-mediated cascading effects on the microbial community in eutrophic warm shallow lakes: a mesocosm experiment,” HYDROBIOLOGIA, pp. 25–35, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/48921.