Abstract

  Stress responses of sediment dwelling organisms offer novel opportunities to identify the bioavailability of contaminants causing toxicity in sediment. Current analytical methods require prior knowledge of likely contaminants and do not assess exposure or bioavailability. Stress responses are dependent upon the dose, type, and bioavailability of a contaminant. Stress responses were monitored using a gene expression profiling technique, restriction fragment differential display, that detects differences in gene expression between exposed and control animals. Infaunal invertebrates, Chironomus tentans and Neanthes aerencodentata, were exposed to nitroaromatic (2,4,6-trinitrotoluene), polyaromatics (fluoranthrene, phenanthrene, and DDT), and metals (Cu, Zn, Hg, and Pb) contaminants. Distinctly different gene expression stress response patterns were observed. The patterns were characteristic of the severity and type of exposure. These results indicate that the pattern, or transcriptional fingerprint, could be used to supplement analytical/exposure procedures by identifying bioavailability of contaminating chemicals while assessing exposure effects. Application of this approach could result in significant cost savings to sediment dredging and remediation operations.