ABSTRACT
Limnocorrals, a type of in situ enclosure or mesocosm, were used by a group of Canadian researchers for 10 years (1979–1988) as a test method for the assessment of pesticide fate and effects in aquatic ecosystems. These mesocosms provide a high degree of ecological realism and have proven valuable for validating toxicological laboratory data and for extrapolating pesticide hazard to the ecosystem level. A number of advantages of limnocorrals and other types of in situ enclosure test designs are briefly described. Despite their advantages, several experimental challenges or difficulties have been encountered in the use of limnocorrals for pesticide field-validation studies. Most of these difficulties, including wall effects and pesticide adsorption to the wall or liner, can, however, be overcome with properly designed experiments. Examples of some of the solutions developed in response to these experimental difficulties are presented.
