Table G-1. Test Specifications for the 28-day Eisenia fetida Bioaccumulation Test

Test Initiation (Day 0). A random sample of earthworms should be

analyzed for the COC as a Day 0 background tissue sample. The Day 0

background tissue sample is used to quantify COC present in earthworms prior

to the test and should not be confused with control or reference tissue samples,

which are exposed to test cylinders for the full 28 days. If greater than 10 per-

cent mortality is seen in control containers, the test is considered invalid. If

earthworms cannot survive in the dredged material, bioaccumulation in the

earthworm is not a concern. Prior to testing, earthworms are rinsed with test

water, and placed on paper towels to remove excess water. On Day 0 the mass of

earthworms needed for the particular chemical analysis procedures for the

contaminant(s) of concern are added to the test cylinder. Test containers have

accommodated up to 30 grams (~75 earthworms)/ cylinder.

Test Breakdown (Day 28). On Day 28, earthworms are removed, rinsed

with test water, blotted, counted, and weighed. The earthworms are depurated

for 24 hr on moist filter paper, then rinsed, reweighed, and frozen in preparation

for chemical analysis.

Feeding. Dredged material that contains organic material does not require

an additional food source. Substrates with lesser nutrients tested with this

procedure may require added food because of test length. Any food added would

need to be chemically analyzed for concentrations of COC.

Test Specifications and Quality Control. A summary of the test

specifications is given in Table G1. Temperature, pH, percent moisture, and

salinity should be controlled or monitored throughout the test. Ideally these

variables should be the same as in the field, and within the range of the

earthworms' requirements. Acceptable temperature range is from 10 to 29 EC

with a recommended range of 19 to 25 EC. Acceptable pH range is between 4

and 10 (Greene et al. 1989). Recommended photoperiod is 24 hr within 100-

1080 lux. This photoperiod is recommended to prevent earthworm escape,

encourage maximum exposure to test material, and to discourage contact with

container sides.

Table G-1

Test Specifications for the 28-day Eisenia fetida Bioaccumulation

Test

Test Duration

28 days

Biological Endpoint

Contaminant accumulation

Same as field condition if within 10-29 οC

Temperature

Photoperiod

24 hr/ 100-1080 lx

Same as field condition if within 4-10

% moisture

Same as field condition

Salinity

Same as field condition

Test Containers

Plexiglas cylinders

Appendix G Animal Bioaccumulation Test Procedures