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Assessing and controlling the risk of cyanobacterial blooms
Published in Ingrid Chorus, Martin Welker, Toxic Cyanobacteria in Water, 2021
Mike Burch, Justin Brookes, Ingrid Chorus
A successful contrasting example from a hypereutrophic subtropical lake in China suggests that cyanobacteria could be controlled directly by fish grazing upon them (Xie & Liu, 2001). This is a different approach from traditional biomanipulation through enhancing zooplanktonic grazers, and it is reported to have been effective for over 30 years.
Application of Ecotechnology in Ecosystem Management of Inland Waters
Published in Sven E. Jørgensen, Jose Galizia Tundisi, Takako Matsumura Tundisi, Handbook of Inland Aquatic Ecosystem Management, 2012
Sven E. Jørgensen, Jose Galizia Tundisi, Takako Matsumura Tundisi
Biomanipulation can only be used in the phosphorus concentration range from about 50 to 130 μg/L dependent on the lake. In this range, two ecological structures are possible. This is illustrated in Figure 17.5. When the phosphorus concentration initially is low and increases, zooplankton is able to maintain a relatively low phytoplankton concentration by grazing. Carnivorous fish is also able to maintain a low concentration of planktivorous fish which implies relatively low predation on zooplankton. At a certain phosphorus concentration (about 120–150 μg/L), zooplankton is not any longer able to control the phytoplankton concentration by grazing and as the carnivorous fish (for instance, Nile perch or pike) is hunting by the sight, and the turbidity increases, the planktivorous fish become more abundant, which involves more pronounced predation on zooplankton. In other words, the structure is changed from control by zooplankton and carnivorous fish to control by phytoplankton and planktivorous fish. When the phosphorus concentration decreases from a high concentration the ecological structure is initially dominated by phytoplankton and planktivorous fish. This structure can, however, be maintained until the phosphorus concentration is reduced to about 50 μg/L. There are therefore two possible ecological structures in the phosphorus range of approximately 50–130 μg/L. Biomanipulation (de Bernardi and Giussani 1995) can be used in this range—and only in this range—to make a “short cut” by removal of planktivorous fish and release carnivorous fish. If biomanipulation is used above 130 μg P/L, some intermediate improvement of the water quality will usually be observed, but the lake will sooner or later get the ecological structure corresponding to the high phosphorus concentration, that is, a structure controlled by phytoplankton and planktivorous fish. Biomanipulation is a relatively cheap and effective method provided that it is applied in the phosphorus range where two ecological structures are possible. de Bernardi and Giussani (1995) give a comprehensive presentation of various aspects of biomanipulation. Simultaneously, biomanipulation makes it possible to maintain relatively high biodiversity which does not change the stability of the system, but a higher biodiversity gives the ecosystem a greater ability to meet future, unforeseen changes without changes in the ecosystem function.
Bioremediation of South Africa’s hypertrophic Hartbeespoort Dam: evaluating its effects by comparative analysis of a decade of MERIS satellite data in six control reservoirs
Published in Inland Waters, 2018
Biomanipulation has long been a controversial approach (e.g., deMelo et al. 1992), with several fundamental ecological criteria well-known to negate its suitability or limit its efficiency (e.g., Gulati et al. 1990, 2008, Wetzel 2001, Drenner and Hambright 2002). While found to be effective in a number of small, shallow natural lakes, overall practical experience has revealed “failure” rather than “success” to be its predominant outcome (e.g., Gulati et al. 1990, 2008, Drenner and Hambright 2002). Two factors widely limiting its applicability – persistent external nutrient overloading (Benndorf 1990, 1995) and fundamental food web constraints (Gliwicz 1990, 2005) – were empirically known to apply in HBPD (Ashton et al. 1985) prior to the onset of HMaM, while food web constraints are now known to apply more generally to reservoirs in the region (Hart 2006, 2011, 2012, Hart and Wragg 2009, Harding and Hart 2013, Hart and Harding 2015). On these grounds, any direct influence of HMaM itself on HBPD was likely marginal at best.
Effects of cyprinid removal and reintroduction: Diamond Lake, Oregon
Published in Lake and Reservoir Management, 2023
J. Eilers, R. Miller, D. Loomis, A. Vogel
One of the in-lake treatments methods employed is biomanipulation in which abundance of one or more groups of organisms is altered to achieve a specific outcome, usually targeting increased Secchi disk transparency and/or decreased cyanobacteria as metrics of success. Biomanipulation frequently involves manipulating fish populations to reduce the biomass of zooplanktivorous (Søndergaard et al. 2008) or benthivorous fish (Meijer et al. 1990), or increase the ratio of piscivorous to zooplanktivorous fish (Lathrop et al. 2002, Skov et al. 2002). Although phosphorus chemistry is targeted in all lakes treated with alum, biomanipulation projects involve objectives that vary by lake because of differences in lake biota.