Effects of waterfowl, large fish and periphyton on the spring growth of Potamogeton pectinatus L. in Lake Mogan, Turkey

2005-03-15
Sandsten, H
Beklioğlu, Meryem
Ince, O
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 excluded from eight plots and both in situ vegetation and macrophytes kept in pots were compared to eight open plots. Also, to investigate the effect of periphyton on plant growth it was removed from half of the pot plants. Exclusion of waterfowl and fish may decrease predation on macroinvertebrates, which in turn may affect periphyton, and macrophyte growth, why macroinvertebrates also were sampled. Waterfowl density was high (15-70 ind. of coot, Fulica atra L. ha(-1)), abundance of submerged plants was also high with a surface coverage of 70-80%, and benthivorous fish were present, mainly tench, (Tinca tinca L.) and carp, (Cyprinus carpio L.). Exclusion of waterfowl and large fish did not significantly affect the spring growth of pondweed; neither plants growing in situ nor kept in pots. Removal of periphyton from the plants in the pots did not favour growth. The density of macroinvertebrates was not affected by the exclusion of waterfowl and large fish, but it was positively related to aboveground biomass of fennel pondweed. We suggest that even if waterfowl and large fish are in high densities, their effect on fennel pondweed spring growth in lakes with abundant submerged vegetation, such as Lake Mogan, is low.
HYDROBIOLOGIA

Suggestions

Effects of plant size on the growth of the submersed macrophyteVallisneria spinulosaSZYan at different light intensities: implications for lake restoration
Yuan, Guixiang; Fu, Hui; Zhang, Meihong; Lou, Qian; Dai, Taotao; Jeppesen, Erik (Springer Science and Business Media LLC, 2020-10-01)
The growth and reproduction of plants are highly size-dependent and markedly affected by light intensity.Vallisneria spinulosaS.Z.Yan is a common submersed macrophyte and is widely used in current lake restoration projects. The size of plants to be used to get optimal restoration results is not known, however, and may vary with water clarity. In this study, the effects of different plant sizes (large, medium and small, i.e. approximately 2.40 g, 1.01 g and 0.27 g per plant) on the growth and reproduction of...
Absence of typical diel vertical migration in Daphnia: varying role of water clarity, food, and dissolved oxygen in Lake Eymir, Turkey
Muluk, CB; Beklioğlu, Meryem (Springer Science and Business Media LLC, 2005-03-15)
Diel vertical migration (DVM) is a complex and dynamic behaviour against predation because the reaction of migrating organisms to light intensity plays a primary role, but is modified by other factors. In the relatively shallow but thermally stratified Lake Eyrnir, Daphnia pulex de Geers utilized vertical refugia afforded by the hypolimnion during both day and night. Differences in general vulnerability to fish predation determined the differences in their mean residence depths (MRDs) of different populatio...
Role of planktonic bacteria in biodegradation of fish-exuded kairomone in laboratory bioassays of diel vertical migration
Beklioglu, M; Gözen, Ayşe Gül; Zorlu, P; Ay-Zog, D (Schweizerbart, 2006-01-01)
Daphnia, freshwater crustaceans that graze algae, often rely on predatory chemical cues termed kairomones as signals for predator-avoidance. Using laboratory bioassays, we studied how planktonic bacteria may modify kairomone activity. We measured the amplitude of diel vertical migration (DVM) of Daphnia pulex DE GEER among treatments with different amounts of bacteria. We used temperature incubation to increase bacterial densities and filtration to reduce abundance. Daphnids exposed to fish cue (F) and filt...
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...
Water level and fish-mediated cascading effects on the microbial community in eutrophic warm shallow lakes: a mesocosm experiment
ÖZEN, ARDA; Bucak, Tuba; Tavsanoglu, Ulku Nihan; Cakiroglu, Ayse Idil; Levi, Eti Ester; Coppens, Jan; Jeppesen, Erik; Beklioğlu, Meryem (Springer Science and Business Media LLC, 2014-11-01)
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...
Citation Formats
H. Sandsten, M. Beklioğlu, and O. Ince, “Effects of waterfowl, large fish and periphyton on the spring growth of Potamogeton pectinatus L. in Lake Mogan, Turkey,” HYDROBIOLOGIA, pp. 239–248, 2005, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/48267.