Jump to main content
Jump to site search

Issue 12, 2004
Previous Article Next Article

High frequency monitoring reveals phytoplankton dynamics

Author affiliations

Abstract

Phytoplankton is an important water quality indicator because of its high species differentiation, growth rates and responsiveness to environmental actuators. The new European Water Framework Directive calls for assessment of the duration, intensity and succession of phytoplankton blooms to determine the ecological status of various types of waters. For common phytoplankton growth rates basic signal processing theory yields a minimum monitoring frequency of once per day, which is much more than applied in standard practice. To assess the nature of this discrepancy we followed the behaviour of about 40 groups of organisms/particles found in the Oude Rijn river by a two-week daily cytometric analysis. Particle counts of the 20 most abundant groups are shown. Their variation rate and magnitude confirm that daily sampling is needed to follow such ecosystems in detail. It is shown that limiting the monitoring to the “coarse line” does not allow a correspondingly decreased sampling frequency. Automated systems may fill the gaps between the microscopical examinations by gathering highly frequent information. The information depth of bulk measurements is poor however, and not used as such. The data shown here demonstrate that modern scanning flow cytometry (SFC) offers an information depth close to the taxonomic level. In the past decade, acquisition and operation costs of these systems have come down considerably, whereas operation is hands free, even in situ and submerged, and data analysis has become more efficient. SFC is used most efficiently complementary to microscopical analyses for mutual validation. In these cases it presents a realistic solution to generate the essential high frequency observations required to assess ecosystem variability.

Back to tab navigation

Publication details

The article was received on 21 Jun 2004, accepted on 29 Sep 2004 and first published on 15 Nov 2004


Article type: Paper
DOI: 10.1039/B409350J
Citation: J. Environ. Monit., 2004,6, 946-952

  •   Request permissions

    High frequency monitoring reveals phytoplankton dynamics

    G. B. J. Dubelaar, P. J. F. Geerders and R. R. Jonker, J. Environ. Monit., 2004, 6, 946
    DOI: 10.1039/B409350J

Search articles by author

Spotlight

Advertisements