space
About UNEP UNEP offices News centre Publications Calendar Awards Milestones UNEP Store
space
space
United Nations Environment Programme
Division of Technology, Industry and Economics
 top image
  space
space space space
  UNEP>DTIE>IETC space
space

Newsletter and Technical Publications
<Planning and Management of Lakes and Reservoirs:
An Integrated Approach to Eutrophication
Abridged Version- A Student's Guide>

Characteristics of Eutrophication

Lakes and reservoirs can be broadly classed as ultra-oligotrophic, oligotrophic, mesotrophic, eutrophic or hypereutrophic depending on concentration of nutrients in the body of water and/or based on ecological manifestations of the nutrient loading. These so-called trophic categories are often based on total phosphorus concentrations, chlorophyll concentrations and Secchi disk visibility. Strict boundaries for these groupings are often difficult to define because of regional variations in limnological parameters (See Figure 1.3 in IETC's Technical Information Series number 11).

In general terms, oligotrophic lakes and reservoirs are characterized by low nutrient inputs and primary productivity, high transparency and a diverse biota. In contrast, eutrophic waters have high nutrient inputs and primary productivity, low transparency, and a high biomass of fewer species with a greater proportion of cyanobacteria than in oligotrophic waters.

 

{short description of image} Table of Contents
  • Brochure
  • IETC Brochure


  • International Year of Forests
  • International Year of Forests


  • World Environment Day
  • ??????


  • UNEP Campaign
  • UNite to Combat Climate Change