Standard Article

The Control of Algal Populations in Eutrophic Water Bodies

Water Quality Control

  1. Joanna Davies1,
  2. Peter M. Scarlett2

Published Online: 15 JUL 2005

DOI: 10.1002/047147844X.wq21

Water Encyclopedia

Water Encyclopedia

How to Cite

Davies, J. and Scarlett, P. M. 2005. The Control of Algal Populations in Eutrophic Water Bodies. Water Encyclopedia. 2:2–7.

Author Information

  1. 1

    Syngenta, Bracknell, Berkshire, United Kingdom

  2. 2

    Winfrith Technology Centre, Dorchester, Dorset, United Kingdom

Publication History

  1. Published Online: 15 JUL 2005


The process of eutrophication is accompanied by increased algal growth, which, without appropriate management, can develop to nuisance proportions. The presence of excessive algae can disrupt the use of many water bodies by restricting navigational and recreational activities and interfering with domestic and industrial water supplies. In particular, algal blooms can have a severe impact on water quality, causing noxious odors, tastes, discoloration, and, in the case of blue-green algae, may also pose a serious health hazard. Ultimately, the presence of excessive algae will inhibit macrophyte growth and reduce biodiversity. The options for controlling algae can be categorized as follows:

  1. Environmental methods involve limiting the availability of those nutrients that are essential for algal growth. These methods involve reducing nutrient inputs from external sources by the processes of diversion, effluent treatment, the use of constructed wetlands, buffer strips, and good agricultural practice. Methods for reducing internal nutrient concentrations include dilution and flushing, hypolimnetic withdrawal, hypolimnetic aeration, artificial circulation, sediment sealing, or sediment removal.

  2. Chemical methods involve the application of herbicides, or products such as barley straw, that have a direct toxic effect on algae.

  3. Biomanipulation involves the control of zooplanktivorous fish to favor algal grazing by invertebrates but also describes the use of microbial products.


  • algae;
  • control;
  • eutrophication;
  • nutrients;
  • phosphorus;
  • herbicides;
  • algicides;
  • barley straw