Assessment of the health status of mussels Mytilus galloprovincialis along Thermaikos Gulf (Northern Greece): An integrative biomarker approach using ecosystem health indices

Pollution biomarkers were assessed in the digestive gland of mussels Mytilus galloprovincialis collected from Greek coasts (Thermaikos and Strymonikos Gulf, Northern Greece) on July 2004. The values of biomarkers were integrated using three ecosystem health indices: health status index (HIS) calculated by the expert system, lysosomal response index (LRI) and integrated biomarker response (IBR). The HIS is based on the integration of the biomarker values, classifying the health status of mussels according to pollution degree. The LRI combines two lysosomal responses (lysosomal membrane stability and lysosomal structural changes) in a single index, which is associated with the ecosystem contamination. The IBR is a useful tool for the visualization of biological responses in marine environments. The results support the use of HIS and LRI as powerful tools for the qualitative and quantitative evaluation of environmental stress, while enhance the use of IBR as a constructive method for the qualitative discrimination of contaminated sites. HIS and LRI revealed high stress conditions in all sampling stations of Thermaikos gulf, whereas unstressed conditions were detected in Olympiada (reference station) by the use of HIS and low stress conditions were shown by the use of LRI. The IBR illustrated higher levels of stress in mussels collected from Thermaikos Gulf, compared to mussels gathered from the reference station. The advantages and disadvantages of the HIS, LRI and IBR are also discussed.