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(T/FF214) Using the zebra mussel (Dreissena polymorpha) as a bioindicator of endocrine disruption. Quinn, Brian1, Lyons-Alcantara, Maria1, Costello, Mark 2, Mothersill, Carmel 1, 1 2 ABSTRACT- The freshwater bivalve Dreissena polymorpha, commonly known as the zebra mussel, is a pest species renowned for fouling hard substrates in lakes and rivers throughout the US and Europe. In this experiment the zebra mussel has been used to investigate the effect of endocrine disruption in invertebrates. In vivo lab exposures to the well known endocrine disrupting chemical nonylphenol, commonly found in effluent from waste water treatment plants, were established. A preliminary exposure of 100, 10, 5, 1 and 0.1 mg/l nonylphenol for 50 days was undertaken to find the LC50 of nonylphenol for the zebra mussel. This was higher than expected with 3.66, 2.13 and 1.79 mg/l needed to kill 50% of the exposed population after 15, 35 and 50 days respectively. Sub-chronic exposure effects such as filtration and byssal attachment were also measured, with rates decreasing after increased exposure to the chemical. In situ exposures of zebra mussels to tertiary treated effluent from a waste water treatment plant, a common source of endocrine disrupting chemicals, were also established. Mussels preserved in paraffin wax blocks from both exposures have been used for immunocytochemical analysis to investigate endocrine disruption by comparing reactivity with numerous antibodies developed against vitellogenin and oestrogen receptors. Other antibodies have also been used to test for effects on cellular proliferation (PCNA, Ki-67), modes of toxicity and cellular stress responses (HSP-70, CYP-450) in mussels exposed to both nonylphenol and sewage effluent. These results shall be presented. It is hoped to use the zebra mussel as a bioindicator of the presence of endocrine disrupting chemicals in the environment. Key words: endocrine disruption, zebra mussel, nonylphenol |
