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(42-05) Light-microscopy and chemical residues in gonads: integrated approach for assessing fish health in biomonitoring program. Sensini, Cristiana*,1, Lancini, Lucia1, Mariottini, Michela1, Corsi, Ilaria1, Focardi, Silvano1, 1 Department of Environmental Sciences University of Siena, Siena, Italy ABSTRACT- Many wildlife species may be exposed to biologically active concentrations of endocrine-disrupting chemicals such as HCB, DDT, PCBs. In the aquatic environment, fish are exposed to a bewildering array of chemicals of various nature and source. The effects of such chemicals seem to be strongly referred to all the interactions among different molecules rather than to the action of a single compound. Fish also face the greatest risk from pollution since their natural habitat is the final resting point of most anthropogenic chemicals. The aim of this study is to assess the health status of a benthic fish species, Mullus barbatus, sampled along the Ionian and Adriatic seas, by evaluating gonadal histology at light microscopy and by detecting organochlorine levels using GC-ECD and GC-MS. Histology showed that ovarian and testis cycle were at the expected prespawning stage; advanced gonadal maturity was observed in ovary and testis samples from the Adriatic sea, as several vitellogenic oocytes and many ripe spermatozoa were present. Residue analysis of gonads showed detectable levels of HCB, p,p′-DDE and PCBs in the following gradient: p,p′-DDE > PCBs > HCB; among coplanar PCBs, pentachlorobiphenyl 33′44′5′ (PCB 126) predominated, followed by tetrachlobiphenyl 33′44′ (PCB-77) and by hexachlorobiphenyl 33and by hexachlorobiphenyl 33′44′55′ (PCB-169). PCB toxicity was determined in terms of toxic equivalency factors (TEFs) which was then used to estimate 2,3,7,8-TCDD toxic equivalents (TEQs). No alterations in either males or females were revealed at light microscopy in terms of exposure to the hormone disrupting pollutants measured, although an abnormal space between the membrane and cytoplasm was observed in some oocytes. Key words: Mullus barbatus, gonads, histology, organochlorines |
