[Critical conditions of the lake Boloiso ecosystem at Braslav Lakes National Park]
2000
Karatshevich, Z. | Samoylenko, V. | Romanov, V. | Veznovets, G. (Belorussian State Univ., Minsk (Belarus))
According to 50-year studies there are great changes of hydrochemical and hydrobiological regime in Boloiso lake. Before 1972 there was low phosphorus load and mesotrophic status of the lake. After the input of sewage water real phosphorus load was exceeded by 20 times in comparison with the permissible one. There is high speed of eutrophication. The modern status of the Boloiso was determined as hypertrophic. There are great changes of temperature and gas regime. In stratified reservoir the hypolimnion size is increased. The hydrogen sulphide zone was formed in the hypolimnion and in some part of metalimnion. During last time the content of nutrients, organic materials, sulphate, chloride, natrium increased. The alkalinity is growing. There are changes of hydrobiological parameters. The biomass of phytoplankton and zooplankton increased. The biomass and species quantity of benthos reduced and practically disappeared in the deeper parts of the lake. The changes of hydrobiological communities dominating complexes is observed
显示更多 [+] 显示较少 [-]