Reproductive Health and Endocrine Disruption in Smallmouth Bass From the Lake Erie Drainage

1Heather L. Walsh, 2Sean D. Rafferty, 1Adam J. Sperry, and 1Vicki S. Blazer

 1U.S. Geological Survey, Eastern Ecological Science Center - Leetown Research Laboratory, 11649 Leetown Road, Kearneysville, WV 25430; 2Pennsylvania Sea Grant College Program, The Pennsylvania State University, Tom Ridge Environmental Center, 301 Peninsula Drive, Erie, PA 16505

ABSTRACT

In this study, smallmouth bass Micropterus dolomieu were collected in May 2016 from three sites in the Lake Erie drainage.  Bass were sampled for histopathology and pieces of liver and testes were preserved for transcript abundance analysis with the Nanostring nCounter® technology.  Evidence of endocrine disruption was assessed by testicular oocytes (TO) and analysis of plasma vitellogenin (VTG) in male fish.  Additionally, transcript abundance of 17 liver transcripts associated with reproduction, endocrine activity, and contaminant detoxification and 40 testes transcripts associated with male and female reproduction, germ cell development, and steroid biosynthesis was assessed.  The results showed males with a high rate of TO (88-100%) and VTG and numerous transcripts that were differentially regulated between the three sites.  At sites with the greatest amount of agriculture and development, TO prevalence and severity was the highest.  Transcript abundance was variable; however, those associated with female reproductive function were greater in males at sites with high agriculture and development.