Skip to main content


Title: Assessment of the feasibility of using image analysis in the oyster embryo-larval development and daphnia magna growth tests
Author: I. Johnson
Author: M. Harman
Document Type: Monograph
At present the majority of ecotoxicity tests involve some form of visual assessment to be made during or at the end of the test, for the determination of the endpoint. These assessments may require the correct recognition and enumeration of different stages of development of the test organism, a measurement of size (such as area or length) or numbers, or whether or not the organism is motile after given exposure periods. These visual assessments are, inevitably, judgmental and may be time consuming. Adoption of the latest electronic imaging technology is expected to benefit many of these tests technically, by improvements in accuracy, reproducibility and lower error rates; and in terms of reduced costs because of improved processing rates. Further benefits may be accrued in areas in which electronic imaging becomes an enabling technology: permitting procedures or tests which require a non-invasive approach or which cannot be performed manually. Image analysis may also facilitate measurements during the time course of a response which could not easily and/or cost-effectively be obtained under other circumstances. However, there remain a number of practical issues which must be addressed before electronic imaging techniques can be applied to ecotoxicity testing. The aims of the study were to address the former issues by applying the latest image capture, processing and analysis techniques to two ecotoxicity tests: the oyster embryo-larval development test and the Daphnia magna growth test integrated with measurements of immobilisation and juvenile production which, between them, encompass most of the required assessments.
Publisher: Environment Agency
Publication Date: 1999
Publication Place: Wallingford
Subject Keywords: Water quality measurementsEcotoxicityBiological indicatorsImageryAnalysisMethodology
Taxonomic Keywords: OstreoideaDaphnia
Extent: 32; + appendices
Total file downloads: 296

Download PDF    Display PDF in separate tab