Titlebook: Nutrient Reduction and Biomanipulation as Tools to Improve Water Quality: The Lake Ringsj?n Story; Lars-Anders Hansson,Eva Bergman Book 19

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The effects of cyprinid reduction on the fish community,e different Basins of Lake Ringsj?n were followed between 1987 and 1994. In 1990, c. 100 tons (60% of the community) were removed from S?tofta Basin, in 1988, c. 500 tons (80%) were removed from Eastern Basin and in 1992, c. 120 tons (50%) of cyprinids were removed from Western Basin. In all basins,

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Juvenile fish expansion following biomanipulation and its effect on zooplankton,tween 1987 and 1994, the total planktivore biomass decreased fourfold whereas the abundance of 0+ fish increased twenty times. The resulting change in predation pressure from planktivorous fish on zooplankton increased up to 2–3 times, after the fish reduction. We conclude that after an initial decr

GULP

Impact of cyprinid reduction on the benthic macroinvertebrate community and implications for increabjected to a substantial reduction of cyprinids (mainly bream and roach). Being totally dominated by chironomids and oligochaetes during the 1980s, the lake became repopulated by groups like Amphipoda, Ephemeroptera, Coleoptera and Mollusca after the fish reduction in 1988–1992. These groups appeare

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,The development of submerged macrophytes in Lake Ringsj?n after biomanipulation, and 1996, and compared with data from 1947 and 1988, in order to investigate the development of submerged macrophytes after the biomanipulation of the lake (completed 1992). The submerged vegetation has declined considerably since 1947, both in species number and outer water depth. The submerged ma

diabetes

,The occurrence of toxic blue-green algae in Lake Ringsj?n, southern Sweden, despite nutrient reduct with a high biomass of blue-green algae as early as 1968. A mouse bioassay in the 1980s confirmed the occurrence of hepatotoxic algae. In 1995, phytoplankton biomass and microcystin concentrations were measured. A mouse bioassay was carried out simultaneously showing that from the end of June, when

evaculate

,Simulating the effects of biomanipulation on the food web of Lake Ringsj?n,the long-term effects of biomanipulation in terms of reduction of omnivorous fish. The model contains 14 state variables, each with a differential equation describing sources and sinks of phosphorus. The state variables encompass piscivorous and omnivorous fish, zooplankton, phytoplankton, sediment

散開(kāi)

Mercurial

nfigurations were compared: (1) surface strips on two interconnectors to be joined are crossed, (2) surface strips on the two interconnectors are parallel. Effects of surface stripes on the electrical-thermal–mechanical behaviors in PGRW of Al interconnectors were investigated by a combination of mi

Painstaking

Lars-Anders Hansson,Magnus Enell,Eva Bergmannfigurations were compared: (1) surface strips on two interconnectors to be joined are crossed, (2) surface strips on the two interconnectors are parallel. Effects of surface stripes on the electrical-thermal–mechanical behaviors in PGRW of Al interconnectors were investigated by a combination of mi