Effects of the novel 'Flock & Lock' lake restoration technique on Daphnia in Lake Rauwbraken (The Netherlands)
Open Access
- 17 August 2010
- journal article
- Published by Oxford University Press (OUP) in Journal of Plankton Research
- Vol. 33 (2), 255-263
- https://doi.org/10.1093/plankt/fbq092
Abstract
We combined a low-dose flocculent (polyaluminiumchloride) with a lanthanum-enriched benthonite clay (Phoslock®) into a novel restoration technique “Flock & Lock”. This treatment was first applied in April 2008 to Lake Rauwbraken, where it stripped all phosphorus (P) from the water column and strongly reduced P-release from the sediment. The treatment had a strong positive effect on water quality, i.e. filamentous cyanobacteria were removed, chlorophyll-a concentration dropped to very low levels of 2 µg L−1, however aluminium, lanthanum and suspended clay concentrations were at least temporally strongly elevated. Following the treatment, Daphnia galeata disappeared for 3 months from the water column within 1 week after application; this phenomenon was not observed in similar periods during 2 years before (2006, 2007) and 1 year after the application (2009). From our field observation and additional grazing (comparing the effects of flocculent, clay and combination of both) and survival experiments (food deprivation), we conclude that the disappearance of D. galeata from Lake Rauwbraken may have been caused by the combination of the physical effects due to flocks, grazing inhibition by flocks and clay, very low food concentrations and absence of predation refuge. However, effects were temporary and Daphnia recovered from the treatment.Keywords
This publication has 30 references indexed in Scilit:
- Phosphorus control is critical to mitigating eutrophicationProceedings of the National Academy of Sciences of the United States of America, 2008
- Lakes in the Netherlands, their origin, eutrophication and restoration: state-of-the-art review*Hydrobiologia, 2002
- The rare earth element geochemistry of Mono Lake water and the importance of carbonate complexingLimnology and Oceanography, 1994
- Effects of suspended clay on Daphnia body growth and fitnessFreshwater Biology, 1992
- Type of suspended clay influences zooplankton response to phosphorus loadingLimnology and Oceanography, 1992
- Suspended clay reduces Daphnia feeding rateFreshwater Biology, 1991
- Suspended Clay and the Population Dynamics of Planktonic Rotifers and CladoceransEcology, 1990
- Investigation of correlation between physicochemical properties of metals and their toxicity to the water flea Daphnia magna StrausEcotoxicology and Environmental Safety, 1989
- Aluminum Bioaccumulation and Toxicity toDaphnia magnain Soft Water at Low pHCanadian Journal of Fisheries and Aquatic Sciences, 1985
- Effects of Various Metals on Survival, Growth, Reproduction, and Metabolism of Daphnia magnaJournal of the Fisheries Research Board of Canada, 1972