Earthworm Test

The OECD guideline for toxicity testing in earthworms No. 207 (OECD, 1984b) utilises adult Eisenia fetida selected for ease of production and maintenance in culture. This earthworm, however, is not a natural soil-dwelling species, and its occurrence in the wild is limited to sites rich in organic matter. Experts have recommended enhancing the ecological relevance of the standard earthworm test by using indigenous soil-dwelling species such as Aporrectodea caliginosa. However, it is said to be difficult to breed and handle in the laboratory (Kula & Larink 1998). We have not found this to be the case, and are currently breeding and maintaining this species with relative ease. Aporrectodea caliginosa is the most common earthworm in New Zealand pastures and inhabits the topsoil, thus making it a far more valuable test species than E. fetida.

Our testing protocol has been adapted from the OECD guideline for use in a New Zealand-relevant species (A. caliginosa), with some fundamental improvements. While the OECD guideline suggests that tests are conducted with the test material dissolved onto a filter paper or in artificial soil, we have found that A. caliginosa does not maintain its health in artificial soil. Therefore, we have developed our test using a standardised laboratory silt loam soil, thus enhancing the ability to extrapolate these test results to New Zealand soils.

Aporrectodea caliginosa

New Zealand Ecotoxicity Test Results

Click on the following links for New Zealand ecotoxicity test results for copper, chromium, and arsenic:

soil micro-organisms
soil invertebrates
- earthworm
- woodlouse
terrestrial plants
aquatic invertebrates
fish.