Biomanipulation as a useful water quality management tool in deep stratifying reservoirs

Scharf, Wilfried

doi:10.1007/s10750-006-0471-y

Cited by 19 publications

(28 citation statements)

References 45 publications

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“…In contrast to these 'biomanipulations,' food-web management in Wupper Reservoir was successful in replacing a smaller daphnid species by a larger one, not only through an increase of daphnid biomass via the proportion of larger specimens (Seda & Kubecka, 1997). Furthermore, it is also likely that the P-load was originally not so high as in hypertrophic Bautzen Reservoir (Benndorf, 1987) preventing a food-web mediated reduction of lake P concentrations (Wright & Shapiro, 1984;Houser et al, 2000;Scharf, 2007). The sequence of events leading to water quality improvement in Wupper Reservoir-nutrient reduction with a subsequent change in food-web structure is consistent with those in Lake Washington and Lake Mendota although in both those lakes continual fisheries management was not the driving force.…”

Section: Discussionmentioning

confidence: 69%

“…The underlying ''top down'' concept of the trophic cascade hypothesis (Carpenter et al, 1985) predicts that ''increased piscivore biomass caused decreased planktivore biomass, increased herbivore biomass, and decreased phytoplankton biomass.'' Irrespective of their original ichthyofauna, in most Central European reservoirs if roach have penetrated into the reservoir cyprinid dominance is the last stage in the natural development of the fish fauna (Vostradovsky et al, 1989;Kubecka, 1993), even under oligo-/mesotrophic conditions (Scharf, 2007). Therefore, it is reasonable to assume that the fish fauna of Wupper Reservoir, which is built in the grayling zone, without any management would be cyprinid dominated with only a few perch reaching the size of piscivory in the long-term (Scharf, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…While there was uncertainty about reservoir's response to biomanipulation, there was no doubt about the success of nutrient load abatement. Since development of the predicted cyprinid-dominated fish fauna could be prevented and a strong piscivorous percid-population plus cyprinids built up (Scharf, 2007), both management measures (reduction of nutrient input rates and food-web management), have proved successful in Wupper Reservoir, both independently and consecutively. Nutrient reduction had already been accomplished in 1993, whereas ''top down'' forces started increasing in 1999 (Scharf, 2007(Scharf, , 2008, as indicated by the replacement of the smaller Daphnia cucullata by the larger Daphnia galeata-hyalina complex.…”

Section: Introductionmentioning

confidence: 99%

“…Since development of the predicted cyprinid-dominated fish fauna could be prevented and a strong piscivorous percid-population plus cyprinids built up (Scharf, 2007), both management measures (reduction of nutrient input rates and food-web management), have proved successful in Wupper Reservoir, both independently and consecutively. Nutrient reduction had already been accomplished in 1993, whereas ''top down'' forces started increasing in 1999 (Scharf, 2007(Scharf, , 2008, as indicated by the replacement of the smaller Daphnia cucullata by the larger Daphnia galeata-hyalina complex. In this article, I shall provide results of Wupper Reservoir's response to nutrient load abatement (''bottom up'') in conjunction with reduced zooplanktivory (''top down''), by comparing the reference regime of high nutrient load and high zooplanktivory (1988)(1989)(1990)(1991)(1992) with both a regime of reduced nutrient load plus unchanged, high zooplanktivory (1993)(1994)(1995)(1996)(1997)(1998) and one of unchanged low nutrient load plus reduced zooplanktivory (1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006).…”

Section: Introductionmentioning

confidence: 99%

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The use of nutrient reduction and food-web management to improve water quality in the deep stratifying Wupper Reservoir, Germany

Scharf¹

2008

Hydrobiologia

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Only a combination of nutrient load abatement and food-web management proved efficient for the management of water quality in the deep stratifying Wupper Reservoir. Reduction of nutrient loading, was completed in winter 1992/1993, but resulted only in reduced winter/spring mixing of phosphorus concentrations. Since the capacity of the diatom spring bloom to remove nutrients from the trophogenic layer of this slightly eutrophic waterbody was never exhausted, the surplus of total phosphorus available to support summer algal growth remained unchanged. Thus, nutrient reduction alone did not improve the water quality, as expected. Subsequent replacement of the smaller Daphnia cucullata by the larger Daphnia galeata-hyalina complex that was attributable to successful foodweb management did, however, result in a shift from a turbid to a clear water regime in 1999. Clearly, the zooplankton community, and therefore food-web structure, played an integral role in nutrient recycling and in the repartitioning of the phosphorus pool. As diatom settling and grazing became much more tightly linked with the appearance of the larger-bodied Daphnia galeata-hyalina complex, which exploits lower-level food resources as early as May, daphnids increasingly acted as a sink for phosphorus. This increased export fluxes out of the pelagic zone and leaves a smaller surplus of total phosphorus to support the accumulation of summer algae. Consequently, water transparency and total chlorophyll concentrations in summer improved with food-web restructuring, indicating real oligotrophication of Wupper Reservoir driven by internal feedbacks.

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Section: Discussionmentioning

confidence: 69%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The use of nutrient reduction and food-web management to improve water quality in the deep stratifying Wupper Reservoir, Germany

Scharf¹

2008

Hydrobiologia

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“…The present analysis indicates that complete fish eradication (if possible) would impact only marginally on internal nutrient stocks and nutrient recycling within the study reservoirs -unlike the common reliance on fish removal as an adjunct component of biomanipulation management in many eutrophic temperate lakes and reservoirs (e.g., Bendorff, 1995;Mehner et al, 2002;Kasprzak et al, 2007;Scharf, 2007;Søndergaard et al, 2008;Pedusaar et al, 2010). This difference appears largely attributable to the inordinately high external nutrient loadings impacting our study reservoirs (Table 1) -1 to 2 orders of magnitude higher than a critical 'biomanipulation efficiency threshold of phosphorus loading' limit (0.6 to 0.8 g TP/m2/yr (< 10 kg TP/ha/yr)) suggested by Bendorff (1987-see Bendorff 1990).…”

Section: Discussionmentioning

confidence: 77%

Impacts of fish on phosphorus budget dynamics of some SA reservoirs: evaluating prospects of ‘bottom up’ phosphorus reduction in eutrophic systems through fish removal (biomanipulation)

Hart¹,

Harding²

2015

WSA

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Data on fish standing stocks in 7 South African reservoirs were used to assess prospects of reducing in-lake amounts of total phosphorus (TP) through remedial biomanipulation -the removal of fish to deplete internal stocks of biomass-incorporated TP and especially to restrict enhancement of TP availability through internal 'bottom up' recycling by fish. Literature-derived conversion functions were used to estimate the quantity of TP stored in fish biomass, recycled by fish through excretion, and released from bottom sediments through carp and catfish bioturbation. This provided a quasi mass-balance assessment of these contributory influences of fish on TP budgets of reservoirs ranging from mesotrophy to hypertrophy in trophic status (annual mean TP levels of 0.04-0.51 mg/ℓ). Absolute contributions of fish were inevitably related directly to reservoir-specific fish stock abundance, both total-fish and coarse-fish biomass levels which increased with trophic status, generating parallel absolute increases in TP sinks and internal TP loading fluxes. On overall average, total fish stock sequestered 2.2 kg TP/ha in biomass, recycled 13.8 kg TP/ha/yr through excretion, and mobilized 8.0 kg TP/ha/yr through sediment bioturbation. Average values relative to external loadings in 5 reservoirs amounted to 3.8% (biomass), 22.8% (excretion) and 11.8% (bioturbation), totalling 38.4%. Most pertinently, the relative importance of fish in reservoir TP budgets declined progressively with rising trophic status, with corresponding averages less than half (1.4, 8.7 and 5.4%, total = 15.4%) in 3 hypertrophic reservoirs (> 0.10 mg TP/ℓ). While total fish eradication plausibly reduces average internal phosphorus by some 40% relative to external load, the corresponding average reduction in hypertrophic reservoirs in greatest need of nutrient reduction is far less (~ 15%). 'Bottom-up' bioremediation accordingly offers little help in the management of nutrient-enriched reservoirs, and is essentially futile where high external nutrient loading persists.

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Alternative Prey Reduces Largemouth Bass Predation Mortality on Newly Stocked Channel Catfish Fingerlings

Becher

Tyszko

Zweifel

et al. 2021

N American J Fish Manag

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Management agencies commonly stock Channel Catfish Ictalurus punctatus as advanced yearlings instead of fingerlings (age 0) to help reduce potential predation mortality despite uncertainty regarding the degree to which predation limits fingerling poststocking survival. To better understand whether fingerling survival during the first 7 d after stocking—when predation risk is likely greatest—could benefit from the presence of alternative prey fish, we conducted an experiment in 0.4‐ha ponds (N = 18; 6 ponds/treatment) that measured fingerling (TL range = 56–186 mm) survival in ponds with predators only (adult Largemouth Bass Micropterus salmoides; mean TL = 327 mm; SE = 21), with predators and alternative prey fishes (Bluegill Lepomis macrochirus and Goldfish Carassius auratus), or with neither (i.e., control ponds). Without alternative prey, fingerling Channel Catfish survival 1 week after stocking was significantly (P < 0.01) lower (89%) than in the ponds with alternative prey (98%) or in the control treatment with no predators (97%). Our experiment also indicated the potential for alternative prey to promote fingerling survival by reducing water clarity, not just by serving as a buffer from predation. Further research, however, is needed to determine the degree to which our findings apply to larger ecosystems and to learn whether stocked fingerlings survive well enough after the initial stocking period to achieve desired management goals. Even so, our results suggest that alternative prey can reduce Largemouth Bass predation mortality on fingerlings immediately after stocking, which could influence Channel Catfish stocking approaches in some managed systems.

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Biomanipulation as a useful water quality management tool in deep stratifying reservoirs

Cited by 19 publications

References 45 publications

The use of nutrient reduction and food-web management to improve water quality in the deep stratifying Wupper Reservoir, Germany

The use of nutrient reduction and food-web management to improve water quality in the deep stratifying Wupper Reservoir, Germany

Impacts of fish on phosphorus budget dynamics of some SA reservoirs: evaluating prospects of ‘bottom up’ phosphorus reduction in eutrophic systems through fish removal (biomanipulation)

Alternative Prey Reduces Largemouth Bass Predation Mortality on Newly Stocked Channel Catfish Fingerlings

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