Phytoplankton associations in a small hypertrophic fishpond in East Hungary during a change from bottom-up to top-down control

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

Phytoplankton species composition and abundance of a shallow hypertrophic fishpond (Mezeshegyi-to, East Hungary) was studied for the period 1992-1995. The pond showed a pronounced algal periodicity. High-diversity phytoplankton assemblages occurred in spring and autumn. During the winter period, low diversity values were related either to stable community states, when K-strategist species dominated the plankton, or to a large bloom of r-strategist species. In summer, the stable environment led to low-diversity, high-biomass phytoplankton assemblages, dominated by Cylindrospermopsis raciborskii. At this time, the growth conditions for Cylindrospermopsis were akin to those prevailing in a continuous fermentor. The overwhelming dominance of this species lasted for more than four months, during which time, the phytoplankton resembled that of one in the tropics. In August, 1993, an unsuccessful chemical treatment for reducing the algal bloom succeeded in killing the pond's entire population of fish. The large fish-stock comprised the planktivorous silver carp. Although the summer of 1994 was one of the warmest summers of this century, the expected Cylindrospermopsis bloom failed to develop probably because of a higher grazing pressure by large zooplankton. In spite of the fact that the temporal and spatial pattern of the phytoplankton is influenced principally by bottom-up effects, changes in cascading trophic interactions may also considerably influence the species composition and biomass.

Original languageEnglish
Pages (from-to)79-90
Number of pages12
JournalHydrobiologia
Volume424
Issue number1-3
DOIs
Publication statusPublished - Apr 15 2000

Keywords

  • Cylindrospermopsis
  • Hypertrophic pond
  • Phytoplankton associations
  • Top-down effects

ASJC Scopus subject areas

  • Aquatic Science

Fingerprint Dive into the research topics of 'Phytoplankton associations in a small hypertrophic fishpond in East Hungary during a change from bottom-up to top-down control'. Together they form a unique fingerprint.

  • Cite this