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Phosphorus limitation in Daphnia: Evidence from a long term study of three hypereutrophic Dutch lakes

DeMott, W.R. and Gulati, R.D. (1999) Phosphorus limitation in Daphnia: Evidence from a long term study of three hypereutrophic Dutch lakes. Limnology and Oceanography, 44, 1557-1564. ISSN 0024-3590.

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Official URL: http://dx.doi.org/10.4319/lo.1999.44.6.1557

Abstract

The Loosdrecht lakes comprise three shallow, interconnected hypereutrophic lakes in The Netherlands. A lake restoration project conducted during the 1980s resulted in reduced phosphorus loading. However, no changes in phytoplankton abundance or species composition were noted, although seston carbon:phosphorus (C:P) ratios increased. Filamentous cyanobacteria and detritus continued to dominate the seston. Moreover, planktivorous fish were very abundant. Relationships between zooplankton abundance and seston abundance and stoichiometry (C:P and carbon:nitrogen ratios) were analyzed using data collected during 9 yr of intensive study of the three lakes. Analysis based on annual means shows surprisingly strong and consistent inverse relationships between Daphnia abundance and the seston C:P ratio for two of the three lakes. In these two lakes (Loosdrecht and Vuntus Lakes), the annual mean abundance of Daphnia cucullata ranged from 104 to 0.7 individuals L-1 over a range in mean seston C:P ratios from about 250 to 500 (molar). In the third lake, Breukeleveen, Daphnia abundance was higher for a given seston C:P ratio, especially during the 2 yr following a biomanipulation project in this lake. Analysis of seston C:P ratios and Daphnia abundance in individual samples provides further evidence that high seston C:P ratios constrained Daphnia abundance in all three lakes. In contrast to Daphnia, the abundances of zooplankters with low P requirements, including Bosmina spp. and cyclopoid copepods, show little relationship to seston C:P ratios. These results suggests that the abundance of Daphnia in the Loosdrecht lakes was determined by the variable P content of their diets and consistently strong fish predation. [KEYWORDS: Zooplankton-phytoplankton interaction; unsaturated fatty-acids; food quality; loosdrecht lakes; mineral limitation; netherlands; ecosystem; growth; cyanobacterium; restoration]

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:10723
Deposited On:25 Nov 2011 01:00
Last Modified:15 Jan 2014 09:33

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