ABSTRACT Sublethal test methods are being used with increasing frequency to measure sediment toxicity, but little is known about the relative sensitivity of these tests compared to the more commonly used acute tests. A study was conducted to compare the sensitivity of several acute and sublethal toxicity methods and investigate their correlations with sedi- ment chemistry and benthic community condition. Six sublethal methods (amphipod: Leptocheirus plumulosus 28-day survival, growth and reproduc- tion; polychaete: Neanthes arenaceodentata 28-day survival and growth; benthic copepod: Amphiascus tenuiremis, 14-day life-cycle; seed clam: Mercenaria mercenaria 7-day growth; oyster: Crassostrea vir- ginica lysosome destabilization; and sediment-water interface testing with embryos of the mussel Mytilus galloprovincialis) and two acute methods (10-day amphipod survival with Eohaustorius estuarius and Leptocheirus plumulosus) were used to test split samples of sediment from stations in southern California and San Francisco Bay. The life-cycle test with the copepod, Amphiascus, proved to be the most sensitive sublethal test and the most sensitive test overall. The Leptocheirus 10-day survival test was the most sensitive of the acute tests. In general, the sublethal tests were not more sensitive to sedi- ments than the acute tests. Of the sublethal tests, only the Amphiascus endpoints and polychaete growth correlated with sediment chemistry. There was poor correspondence between the toxicity end- points and indicators of benthic community condi- tion. Differences in test characteristics such as mode of exposure, species-specific contaminant sensitivity, changes in contaminant bioavailability, and the influ- ence of noncontaminant stressors on the benthos may have been responsible for variation in response among the tests and low correspondence with benth- ic community condition. The influence of these fac- tors cannot be easily predicted, underscoring the need to use multiple toxicity methods in combination with other lines of evidence to provide an accurate and confident assessment of sediment toxicity. INTRODUCTION Acute sediment toxicity testing has been routine- ly conducted as part of monitoring and assessment programs, such as the USEPA’s Environmental Monitoring and Assessment Program (Strobel et al. 1995). The toxicity tests are usually conducted on whole sediments using amphipod 10-day survival tests in accordance with standard protocols (USEPA 1994). Sublethal testing has been conducted on a much more limited basis, but there is increased inter- est in using sublethal methods due to the assumption that they are more sensitive to contaminated sedi- ments than the acute methods (Adams et al. 2005). Sublethal methods include embryo development tests and other tests with various life stages of animals having endpoints such as growth and reproduction in addition to survival. A wide variety of sublethal methods have been described (Lamberson et al. 1992); very few of these methods have been used commonly. Regularly used sublethal test methods include the amphipod Leptocheirus plumulosus 28-day growth and reproduction test (USEPA 2001), a 20-day polychaete growth test using Neanthes are- naceodentata (PSWQA 1995), pore water testing using echinoderm gametes or embryos (Carr and Nipper 2003), and a sediment-water interface (SWI) Comparison of methods for acute and chronic toxicity in marine sediments Darrin Greenstein, Steven Bay, Brian Anderson 1 , G. Thomas Chandler 2 , J. Daniel Farrar 3 , Charles Keppler 4 , Bryn Phillips 1 , Amy Ringwood 5 and Diana Young 1 University of California Davis, Monterey, CA 2 University of South Carolina, Columbia, SC 3 US Army Engineer Research and Development Center, Vicksburg, MS 4 Marine Resources Research Institute, Charleston, SC 5 University of North Carolina-Charlotte, Charlotte, NC Acute and chronic toxicity in marine sediment - 277