Scaphirhynchus Conference: Alabama, Pallid, and Shovelnose Sturgeon

St. Louis, Missouri, 11-13 January 2005

46.  SENSITIVITY OF SHOVELNOSE STURGEON (SCAPHIRHYNCHUS PLATORYNCHUS) TOWARD TCD OR A CHLORDANE MIXTURE: EARLY LIFE STAGE DEVELOPMENT AND SURVIVAL.

Donald E. Tillitt*, U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, Missouri 65201; Phone 573-876-1886; FAX 573-876-1896; dtillitt@usgs.gov

Diana M. Papoulias, U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, Missouri 65201; Phone 573-876-1902; FAX 573-876-1896; dpapoulias@usgs.gov

James Candrl, U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, Missouri 65201; Phone 573-441-2967; FAX 573-876-1896; jcandrl@usgs.gov

Mandy L. Annis, U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, Missouri 65201; Phone 573-441-2940; FAX 573-876-1896; mannis@usgs.gov

Diane K. Nicks, U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, Missouri 65201; Phone 573-876-1848; FAX 573-876-1896; dnicks@usgs.gov

Michael Coffey, U. S. Fish & Wildlife Service, Region3, Rock Island Ecological Services Field Office, Rock Island, IL; Phone 309-793-5800 (x206); Michael_Coffey@fws.gov

Sturgeon from the Mississippi and Missouri Rivers are exposed to a variety of agricultural, industrial, and pharmaceutical chemicals.  The importance of these exposures has been impossible to assess because the sensitivity of sturgeons has not been established.   Therefore, it was the objective of this study to determine the sensitivity of early life stages of shovelnose sturgeon (Scaphirhynchus platorynchus)  towards chlordanes and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), two chemicals with elevated concentrations in these rivers.  Dose-related increases in mortality and pathologies were observed with TCDD treatments.  The suite of symptoms observed (hemorrhage, yolk sac edema, craniofacial anomalies) is classic for TCDD.  The LD50 for TCDD toward shovelnose sturgeon early life stage toxicity was 12.9 ng/g egg; while the no observable adverse effects level (NOAEL) was 2.1 ng/g egg.   The studies evaluating the toxicity of chlordane to early life stage growth and development in shovelnose sturgeon were not as successful as the studies with TCDD.  Poor egg quality resulted in low survival in control groups which confounded much of the results.  Even so, there were some dose-related symptoms of toxicity that can be used to develop threshold values.  Elevated pathologies were observed in fry at the medium dose of the chlordane mixture (21 ug/g, estimated) and this dose would be considered the lowest observable adverse effect level (LOAEL) for this mixture of chlordanes in shovelnose sturgeon early life stage toxicity.  The lowest dose, 2.1 ng/g egg (estimated), would be considered the NOAEL for the mixture of these compounds of chlordane.  The information from this study will be useful for toxicological evaluation of TCDD and TCDD-like compounds measured in field-derived sturgeon.