Elevated gonadal atresia as biomarker of endocrine disruptors: Field and experimental studies using Mytilus trossulus (L.) and 17-alpha ethinylestradiol (EE2).

In the present work we compared the type and frequency of gonadal abnormalities among Mytilus trossulus populations from the Gulf of Gdansk, Baltic Sea. Observed histopathologies were grouped as regressive changes (RC, gonadal atresia (GA) and regression (GR)), progressive changes (PC, gonadal tumors) and intersex. Sex-based and spatial differences in frequency of RC were found, with the highest frequency of RC and PC found in mussels from polluted station B followed by mussels from station A located near a purification plant outlet. Bivalves from the reference area had the lowest frequency of RC. In order to confirm biomarker applicability of RC, an exposure experiment with model xenoestrogen 17α-ethinylestradiol (EE2) was performed. The exposure of M. trossulus to 50 and 500ngdL-1 of EE2 resulted in an increased frequency of gonadal regression and atresia, including melanized hemocytes infiltration in seminiferous tubules. We thus suggest that these changes can serve as biomarkers of endocrine disrupting compounds in biomonitoring studies.

Nodularia spumigena peptides--accumulation and effect on aquatic invertebrates.

Thus far, the negative effects of Nodularia spumigena blooms on aquatic organisms have been mainly attributed to the production of the hepatotoxic nodularin (NOD). In the current work, the accumulation of other N. spumigena metabolites in blue mussels and crustaceans, and their effect on Thamnocephalus platyurus and Artemia franciscana, were examined. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses provided evidence that both blue mussels collected after a cyanobacterial bloom in the Baltic Sea and the crustaceans exposed under laboratory conditions to N. spumigena extract accumulated the cyclic anabaenopeptins (APs). In the crustaceans, the linear peptides, spumigins (SPUs) and aeruginosins (AERs), were additionally detected. Exposure of T. platyurus and A. franciscana to N. spumigena extract confirmed the negative effect of nodularin on the organisms. However, high numbers of dead crustaceans were also recorded in the nodularin-free fraction, which contained protease inhibitors classified to spumigins and aeruginosins. These findings indicate that cyanobacterial toxicity to aquatic organisms is a complex phenomenon and the induced effects can be attributed to diverse metabolites, not only to the known hepatotoxins.