Determination of the Limiting Plant Nutrient in the Water of Lake Balaton by Algal Assay Procedure

Abstract

llgiil iis~:ty~ were performed on water samples taken from different sites in Lake Baluton. Selcwtstrtcni capricornuturn was used in the test to determine the primarily limiting plant nutrient. The results of siipplementary nutrient additions to the bottle tests were evaluated by cell counts. Thr tests have indicated phosphorus as growth rate limiting, and in two cases a8 biomass limiting plant nutrient, but periodic occ'urrences of nitrogen limitittion cnnnot be excluded. sis of organically bound phosphorus, making it readily available (HEALBT, 1973 ; KL~HI,, 1974; OVERBECK, 1962)..Acrordingly, the question arises of whother phosphorus litnitat ion in thc water of Lzke lialaton can be verified by an algal assay. The studies with the green alga 5618 S c e t~s~l e s m u s obtusiusculus CHOD. (FELFBLDY, 1959(FELFBLDY, , 1962 failed to prodnce the resiilta anticipated froin the chemistry of the lake water, i.c. the test algae indicatcd that 59 Int. l'.e!uc ges 1C)drobiol. VoI. 06, So. 0

Changes of phosphorus and nitrogen concentration and of phytoplankton in enriched lake enclosures1

“…Dobolyi and Herodek (1980) showed that 32P043-added to water samples was incorporated by living organisms and was neither adsorbed onto suspended solids nor coprecipitated with biogenic lime. Since the amount of P coprecipitating with CaCO, depends on the POd3-concentration, which in turn is held at an extremely low level by the competing planktonic microorganisms, the amount of P coprecipitating with CaCO, may be much less than existing estimates suggest (Istvanovics and Herodek 1985).…”