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Evidence of endocrine disruption of common carp at Willow Beach: Do we have an answer?

Evidence of endocrine disruption of common carp at Willow Beach: Do we have an answer?.

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Evidence of endocrine disruption of common carp at Willow Beach: Do we have an answer?

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  1. Evidence of endocrine disruption of common carp at Willow Beach: Do we have an answer? Michael R. Rosen1, Reynaldo Patiño2, David Alvarez3, Steven Goodbred4, and Kathy Echols3U.S. Geological Survey, 1Water Science Field Team, NV; 2 Texas Cooperative Fish & Wildlife Research Unit; 3Columbia Environmental Research Center; 4Emeritus, North Carolina

  2. Why are we concerned with Willow Beach? Seminoma One female Common Carp taken in 2003 showed signs of intersex with spermatozoa visible in ovarian tissue and poor development of testicular tissues in male carp (Hinck et al., 2006; 2007) Oocytes Spermatozoa In 2007/2008 Additional sampling at Willow Beach confirmed intersex in female fish and 3 of 5 male fish had possibly malignant testicular tumors (seminoma) Testes from Willow Beach male carp

  3. Fish Tissue and sediment samples collected in 2005 suggested organic chemicals (PCBs) may be an issue

  4. Fish Tissue 2007 - 2008 mean concentration (n = 6 – 20 fish per site)

  5. Endocrine Disruption in Lake Mead • Summary of field-based studies on Common Carp • The reproductive and endocrine condition of male carp in LMNRA differed among sampling sites and can be classified from higher to lower as follows: • OA > LVB > LBW > WB. • Especially notable were • The weak seasonality in the reproductive physiology of male fish from LVW and WB; • The poor condition of fish from WB including the incidence of gonadal tumors and other reproductive organ anomalies.

  6. What is the reason(s) for these endocrine issues in carp from Willow Beach Several possibilities exist: Effluent from wastewater plant at Hoover Dam Effluent from wastewater from the Fish Hatchery PCBs from leaking transformers at the Dam Contaminants transported down from Lake Mead Environmental factors such as cold water released from Hoover Dam, low food or nutrient supplies, erosion of naturally occurring toxic minerals into the lake Old population of carp

  7. Currentstudy In order to assess some of these possible sources: Sediment, attached algae, and water (SPMD/POCIS) were collected at sites above and below the Fish Hatchery (5 sites total) Fish were collected for histopathology all around these sites Food, caulk, and rubber were sampled at the Fish Hatchery.

  8. Sampling sites along Willow BeachTotal distance is about 5 miles from site 1 to site 5 Hoover Dam Fish Hatchery Lake Mohave 2 miles Google Earth Image

  9. Results

  10. Fish Hatchery materials and feed

  11. Algae and sediment

  12. SPMD/POCIS Samples No PCBs found in water samples (not surprising) Concentrations of DDT metabolites, PAHs hexachlorobenzene (HCB), heptachlor, heptachlor epoxide, dieldrin, PBDE-47 and -99, triclosan and methyl triclosan are all higher than at Overton Arm, but not as high as Las Vegas Bay Other chemicals are present however, but at low concentrations: no greater than Overton Arm: However….

  13. Examples of other constituents in the water at Willow Beach

  14. Water Temperature and Seasonality Temperature of Hoover Dam outlet water is generally cold: 52 – 55 oF (11 – 13oC) Temperature doesn’t change much seasonally Carp spawn from May to June at 64 – 86°F (18 – 30°C) with optimum of 73°F (23°C) Therefore, cold temperatures and lack of seasonality may contribute to poor fish health

  15. Seasonality in Fish • E2/KT Ratio Highlights: E2/KT levels generally lower in OA than other sites, except WB. Seasonality absent in LVW and WB. • Within a site, columns with same letter are not different • Asterisk - different from corresponding date in reference site (OA)

  16. Fish Histopathology 2010 GSI (%) Testes MA area (%) Intestitia Thickness (mm)

  17. Conclusions There isn’t any smoking gun Fish Hatchery materials appear to have some PCBs in them and perhaps had more in the past Estrogenic chemicals were detected in the water near the Hatchery PCBs and other contaminants occur at low concentrations upstream of the Hatchery Low temperature of the water and lack of seasonality can’t be discounted as a contributing factor

  18. Thanks to NPS and FWS for access to sites on Lake Mohave and the Fish Hatchery Funding was from the USGS-NPS collaborative Water Quality Partnership Program

  19. Questions?

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