Differences in the ability of two marine annelid species, Thalassodrilides sp. and Perinereis nuntia, to detoxify 1 nitronaphthalene.
Bioremediation is a promising method for remediating environmentally polluted water. We investigated the abilities of two benthic annelid species to biotransform 1 nitronaphthalene, a nitrated polycyclic aromatic hydrocarbon. We used an oligochaete, Thalassodrilides sp. (Naididae) collected from the sediment beneath a fish farm and a polychaete, Perinereis nuntia, which was obtained from a commercial source. Populations of both organisms were exposed to 1400 mg L( 1) of 1 nitronaphthalene in seawater for 3 days in the dark at 20 degC. The concentration of the pollutant decreased to 12 mg L( 1) in the seawater containing the Thalassodrilides sp. and to 560 mg L( 1) in the seawater containing P. nuntia. The 1 nitronaphthalene concentration in the bodies of the animals increased from 12 to 94 mg kg( 1) in Thalassodrilides sp. and from 0.90 mg kg( 1) to 38,000 mg kg( 1) in P. nuntia. After 3 days, 99% and 40% of the 1 nitronaphthalene had been biotransformed in the Thalassodrilides sp. and P. nuntia experimental groups, respectively. We then tested the acute toxicity of residual 1 nitronaphthalene from the same water using mummichog (fish) larvae. After the larvae had been exposed for 96 h, the percentage of apparently unaffected larvae remaining was 83.3% in Thalassodrilides sp. group but only 16.7% in the P. nuntia group. Clearly, of the two species we studied, Thalassodrilides sp. had a superior ability to convert 1 nitronaphthalene into substances that were nontoxic to mummichog larvae. Therefore, we recommend the use of this species for bioremediation of chemically polluted sediments.
Chemosphere