WP16 Sediment Quality Assessment
Wednesday, 16 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(YOU-1117-831821) Inter-laboratory variation and applicability of sublethal sediment test methods using Mercenaria mercenaria, and Mytilus galloprovinciallis.

Young, Diana¹, Bay, Steve¹, Greenstein, Darrin¹, Anderson, Brian², Phillips, Bryn ², Ringwood, Amy³, Keppler, Charles ⁴, Hester, Brian⁵, ¹ Southern California Coastal Water Research Project, Westminster, CA, USA² University of California Davis, CA, USA³ University of North Carolina-Charlotte, Charlotte, NC, USA⁴ Marine Resource Research Institute, Charleston, SC, USA⁵ Weston Solutions, Carlsbad, CA, USA

ABSTRACT- The use of aquatic invertebrates for acute sediment toxicity testing to assess sediment quality is widespread and well standardized. Chronic/sublethal tests have the potential to detect effects at lower levels of contamination than acute tests. However, the use of chronic/sublethal endpoints is not as consistent as the use of acute tests and has not been standardized. Chronic/sublethal toxicity tests have been developed for many different aquatic species, yet little is known about their comparability and reliability. Chronic/sublethal toxicity tests with embryo and juvenile marine invertebrates are an attractive option due to small sample requirements, potential sensitivity at early life stages, and ready availability of test organisms. The objectives of this study were to investigate the sensitivities and applicability of two sublethal toxicity tests and to determine the variability of these tests among three laboratories. The chosen tests were the 7-day sediment bioassay with juvenile clams (Mercenaria mercenaria) having growth and survival as endpoints and the 2-day sediment-water interface bioassay for mussel embryo (Mytilus galloprovinciallis) with development as an endpoint. Inter-laboratory testing was preformed using three concentrations of nonylphenol spiked sediment. In addition to the spiked sediment three dilutions of highly contaminated field sediment were also tested. The different sediment samples were distributed to participating laboratories that had different levels of experience with these tests. The clams showed minimal response to the contaminated field sample in comparison to controls. When exposed to nonylphenol, the clams showed a reduction in growth. The mussels exhibited a small decrease in normal development when exposed to the contaminated field sample. In contrast nonylphenol had a strong effect on mussel embryo development. Variations in growth and development between the labs were present showing that these tests need to be further standardized.

Key words: inter-laboratory, sediment, sublethal, toxicity