Vitellogenin in Pimephales promelas was used to assess estrogenicity of a local municipal effluent. Vitellogenin induction in male P. promelas increased in frequency and magnitude with increased exposure duration and was greater ("=0.05) than controls after 2 and 3 weeks of exposure. The level of vitellogenesis induced by effluent exposure was high compared to similar studies. A spring season evaluation followed. Biomarkers in P. promelas were used to assess the efficacy of a treatment wetland to remove toxicity and estrogenicity in final treated wastewater effluent. Comparisons were made with an effluent dominated stream and laboratory controls. Vitellogenin, GSIs (gonado-somatic indices), HSIs (hepato-somatic indices) and secondary sexual characteristics were biomarkers used in P. promelas models to assess aqueous estrogenicity. Biological indicators used to assess general fish health included hematocrit and condition factors. The estrogenic nature of the effluent was screened, concurrent with fish exposure, with GC/MS analysis for target estrogenic compounds including: 17-b estradiol, estrone, ethynylestradiol, Bisphenol A, nonylphenolic compounds, phthalates, and DDT. Plasma vitellogenin measured in P. promelas was significantly elevated (p < 0.0001) at the inflow site of the wetland and stream sites. GSIs for these exposures were less (a=0.001) at the wetland inflow site. At wetland sites closest to the inflow, secondary sexual charateristics, tubercle numbers and fat pad thickness, were less (a=0.0001). Hematocrit and condition factors were less (a=0.001) at sites closer to the wetland inflow. Seasonal variation was examined by repeating the effluent characterization in summer. Additionally, summer testing included exposure to an effluent dilution series. Fish condition heavily influenced interpretation of the results. Pre-acclimation exposure to spawning stresses may have altered many of the biological markers measured. Results are discussed relative to fish health and pre-exposure environment. Toxicity assessed with P. promelas biomarkers was compared with Ceriodaphnia dubia and Vibrio fischeri toxicty tests on this effluent. Biomarkers of fish health were somewhat less sensitive than C. dubia test endpoints, but more sensitive than V. fisheri.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc2676 |
| Date | 12 1900 |
| Creators | Hemming, Jon M. |
| Contributors | Waller, William T., Dickson, Kenneth L., Kennedy, James H., Mayer, Foster L., Doyle, Robert D. |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | Text |
| Rights | Public, Copyright, Hemming, Jon M., Copyright is held by the author, unless otherwise noted. All rights reserved. |
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