PARENT SESSION
PT2 - Endocrine Disruption
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P582) Laboratory exposure of adult male and female goldfish (Carassius auratus) to sodium perchlorate: investigation of potential impacts on reproductive and thyroid system function.
Crouch, Neil*,1, Snyder, Shane2, Van Der Kraak, Glen3, Kelly, Kevin4, Fitzgerald, Scott5, Snyder, Erin1, 1 Pennsylvania Cooperative Fish and Wildlife Research Unit, U.S.G.S. Biological Resources Division, University Park, PA, USA2 Southern Nevada Water Authority, Boulder City, NV, USA3 University of Guelph, Guelph, Ontario, Canada4 U.S. Bureau of Reclamation, Denver, CO, USA5 Michigan State University, East Lansing, MI, USA
ABSTRACT- With the development of new analytical detection capabilities, perchlorate contamination has been found in ground and surface waters across the United States. Perchlorate, as ammonium perchlorate, is a powerful oxidant used in solid rocket fuels; hence, sources of contamination generally occur near military test sites and chemical manufacturing plants. This anion is known to inhibit thyroid function in many animals, and concentrations in some locations have been found at ppm levels in surface water inhabited by fish. The toxicological concern is that environmental levels of perchlorate may impact thyroid and reproductive systems of fish. This hypothesis was tested with adult male and female common goldfish (Carassius auratus) in a laboratory flow-through exposure system. Goldfish were exposed for 4 weeks, under conditions designed to stimulate spring gonadal recrudescence, to four environmentally relevant concentrations of perchlorate ranging from 10 ppb to 25 ppm, plus a control. Both thyroid and reproductive endpoints were examined. The gonadosomatic index (GSI = (gonad weight / body weight) *100) is a measure of seasonal reproductive development. The average GSI for females exposed to 0 ppb, 10 ppb, 100 ppb, 1000 ppb, and 25 ppm were 14.44 (±5.65), 12.82 (±4.76), 13.72 (±5.34), 15.31 (±4.02), and 14.59 (±5.42), respectively. The average GSI for males exposed to the same concentrations were 4.65 (±1.25), 4.31 (±1.02), 4.62 (±1.36), 4.63 (±1.16), and 4.48 (±0.99), respectively. These GSI are typical for goldfish in the predicted state of reproductive development; thus seasonal gonadal growth does not appear to have been substantially affected by exposure to this range of perchlorate concentrations for 4 weeks under these conditions.
Key words: thyroid, fish, reproductive system, perchlorate