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U.S. Department of Energy
Office of Scientific and Technical Information

Evaluation of Mysidopsis bahia fecundity endpoint

Conference ·
OSTI ID:244892
The M. bahia chronic toxicity test is commonly used to test estuarine and marine effluent discharges. The test evaluates three endpoints: survival, growth, and fecundity. The fecundity endpoint is often erratic over time and does not necessarily predict accurately other endpoints of effluent toxicity. Therefore, an analysis of the fecundity endpoint was performed to evaluate its use in compliance testing. The endpoint analysis was conducted in three phases: a literature search, analysis of M. bahia data from 24 separate testing events, and interviews with various policy makers, statisticians, and biologists. The literature search revealed a dozen publications, none of which evaluated fecundity using the EPA method. The literature suggested that evaluating fecundity was labor-intensive and inadequate for practical compliance testing applications. Analysis of the 24 tests revealed that fecundity was evaluated only half of the time (i.e. when at least 50% of the females in the control were fecund). There was a high coefficient of variation (C.V.) between replicates for fecundity (range = 9.--1209.3,x = 85.2%) as compared to survival (range = 0.0--24.0,x = 13.7 %) and growth (range = 7.5--43.9,x = 19.1%). The fecundity results were erratic and did not always follow a dose-response curve, due in part to the small sample size per replicate. Interviews showed that the fecundity endpoint was being evaluated differently by different laboratories. Some were using fecundity for compliance while others were not. Most people interviewed recognized there were inconsistencies with the endpoint. The conclusions drawn from the evaluation were that (1) fecundity does not lend itself for use as a compliance endpoint, (2) the fecundity evaluation process is time consuming and labor intensive, and (3) interpretation of the results is not consistent from laboratory to laboratory and from region to region.
OSTI ID:
244892
Report Number(s):
CONF-9511137--; ISBN 1-880611-03-1
Country of Publication:
United States
Language:
English