PARENT SESSION

3A - Biomarker/Biomonitoring
Hall 8
8:30 AM - 12:30 PM, Tuesday, 29 April 2003
Chair: Garrigues, Ph.¹, ¹

(TU8/5) Bioaccumulation and effects of PCBs in the common sea star Asterias rubens.

Danis, Bruno¹, Dubois, Philippe¹, Warnau, Michel², ¹ Université Libre de Bruxelles, Brussels, Brussels, BELGIUM² International Atomic Energy Agency-Marine Environment Laboratory, Monaco, Monaco, Principalty of Monaco

ABSTRACT- This paper presents an overview of investigations carried out both in laboratory and field conditions on PCB bioaccumulation and effects in the common sea star Asterias rubens, a key species in the North Sea and the NE Atlantic . In the laboratory, individuals were experimentally exposed (1) to two structurally contrasted congeners (coplanar #77 and non-coplanar #153) via sea water, sediments or food and (2) to a mixture of 10 PCBs via sediments. Bioaccumulation was determined using both classical analytical techniques (GC-MS and GC-ECD) and radiodetection of ¹⁴C-labelled compounds (liquid scintillation counting). Simultaneously, biological effects at immunological (reactive oxygen species -ROS- production) and molecular (CYP1A1 protein induction) levels were assessed. These experiments showed that PCB bioaccumulation varies according to body compartment, exposure mode and congener planarity. Strong correlations were found between cPCB concentrations measured in sea stars and both ROS production and CYP1A1 induction. Similar correlations were also observed in toxicity tests conducted on sea stars injected with PCBs. In the field, PCB and PCDD/F levels, ROS production and CYP1A1 induction were monitored in sea stars and sediments of the southern North Sea. Among the 24 stations investigated, those under direct influence of the Scheldt River were found to be the most affected by the considered contaminants. A strong correlation was found between CYP1A1 and levels of cPCBs and dioxins. On the whole, results showed a straightforward relationship between dioxin-like compounds exposure and CYP1A1 induction in A. rubens. This kind of responsiveness has been described in vertebrates, but never in echinoderms. It appears that this group has a major potential for bioindication. In particular, CYP1A1 measurement in sea stars is shown to be an excellent tool for screening and monitoring highly toxic compounds.

Key words: PCB, Asterias rubens, bioaccumulation, effects