The OECD guideline for toxicity testing in earthworms No. 207
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.
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.
the following links for New Zealand ecotoxicity test results
for copper, chromium, and arsenic: