Bioavailability and chronic toxicity of cadmium in sediment to the estuarine amphipod Leptocheirus plumulosus

✍ Scribed by Theodore H. Dewitt; Richard C. Swartz; David J. Hansen; Douglas McGovern; Walter J. Berry

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 114 KB
• Volume: 15
• Category: Article
• ISSN: 0730-7268
• DOI: 10.1002/etc.5620151205

✦ Synopsis

Numerous studies have demonstrated the efficacy of interstitial water metal concentrations and simultaneously extracted metals/acid-volatile sulfide (SEM/AVS) ratios in explaining the acute toxicity of sediment-associated metals to benthic organisms. However, no full life-cycle chronic marine or estuarine tests have been conducted for this purpose. In this study, cohorts of newborn amphipods, Leptocheirus plumulosus, were exposed to cadmium-spiked estuarine sediment for 28 d to determine effects on mortality, growth, and reproduction relative to interstitial water and SEM/AVS normalization. Seven treatments of cadmium were tested: 0 (control), 0.34, 0.74, 1.31, 1.55, 2.23, and 4.82 M SEM Cd /AVS ratios (measured concentrations). Interstitial water cadmium (IW Cd ) and sediment concentrations of SEM Cd and AVS were monitored periodically and by depth during the exposure. When sediment SEM Cd /AVS ratios were Յ1.55, mean IW Cd concentrations were less than the 96-h water-only cadmium LC50 for juvenile and subadult L. plumulosus, and mortality, growth, and reproduction were not affected. When SEM Cd /AVS ratios were Ն2.23, IW Cd concentrations were more than 100 times greater than the 96-h water-only cadmium LC50, and all amphipods died. These results are consistent with predictions of metal bioavailability from acute tests with metal-spiked sediments, i.e., that sediments with SEM Cd / AVS ratios Ͻ1 are not toxic, while sediments with SEM Cd /AVS ratios Ͼ1 may be toxic.