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(42-12) Gonad development and steroid hormones in female perch Perca fluviatilis exposed to refuse dump leachate . Noaksson, Erik*,1, Linderoth, Maria1, Zebühr, Yngve1, Gustavsson, Bodil1, Broman, Dag1, Balk, Lennart1, 1 Laboratory for Aquatic Ecotoxicology, Institute of Applied Environmental Research (ITMx), Stockholm University, Stockholm, Sweden ABSTRACT- Swedish refuse dumps could be viewed as very potential point sources of less known anthrophogenic substances since their construction cause diffuse dispersal of leakage water. Recently, we observed that 75% of the female perch Perca fluviatilis in Lake Molnbyggen, contaminated by leakage water, were arrested in a sexually non-reproducible immature stage associated with very high frequencies of fin erosion and open sores, decreased gonadosomatic index (GSI), lower P450arom activity, and reduced circulating levels of especially testosterone but also oestradiol. In order to further investigate the molecular mechanism and to define critical timeframes for the use of reproductive biomarkers, a study throughout 13 months was conducted on female perch focused on the analysis of circulating steroid hormones in blood plasma by the use of GC/MS, in addition to liversomatic index (LSI), GSI, and P450arom activity. Female perch were captured once a month from the reference Lake Djursjon and Lake Molnbyggen. In order to prevent further contamination of Lake Molnbyggen the leakage water has been routed to a sewage treatment work at Lake Siljan. Female perch were therefore sampled down-stream and up-stream of this treatment work at three different occasions. Results show that there still is a very high percentage of non-reproducible female perch at Lake Molnbyggen. However, skin lesions, such as sores, appears to be much less frequent, as well as differences in the P450arom activity, indicating less contamination. Markedly reduced numbers of sexually mature female perch were observed down-stream the sewage treatment work in Lake Siljan. In summary, steroid profiles run by GC/MS from the different locations will reveal if the endocrine disruption previously observed in perch from Lake Molnbyggen also could be found in female perch down-stream the sewage treatment work, thus providing evidence of insufficient wastewater treatment of endocrine disruptive substance(s) in the leakage water from the refuse dump. Key words: Steroid hormones, P450arom (CYP 19), GC/MS, Refuse dump |
