High levels of ammonia in sediment toxicity tests can potentially confound test results. At issue is whether the observed toxicity is due to elevated ammonia or the presence of more persistent anthropogenic contaminants. To evaluate the risk of ammonia toxicity, information on (1) the exposure-respo
Development of a chronic sublethal sediment bioassay using the estuarine amphipod Leptocheirus plumulosus (Shoemaker)
โ Scribed by Vallen L. Emery Jr.; David W. Moore; Brian R. Gray; B. Maurice Duke; Alfreda B. Gibson; Rachel B. Wright; J. Daniel Farrar
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 124 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0730-7268
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โฆ Synopsis
Abstract
Based on the need for a test to evaluate chronic sublethal toxicity in estuarine sediments, a 28โd sediment bioassay with the estuarine amphipod Leptocheirus plumulosus (Shoemaker) was developed. The test was initiated with animals less than 2 weeks old (i.e., 425โ600 ฮผm sieved size class). Test endpoints included survival, growth (ฮผg dry weight/d), and reproduction (number of neonates/surviving female). Factors with the potential to influence test animal performance (i.e., nontreatment factors) such as artificial sea salts, salinity, food ration, size at test initiation, intraspecific density, sediment grain size, and diet were evaluated. For example, intraspecific densities between 10 and 60 animals/beaker (i.e., 0.18โ1.4 animals/cm^2^) did not affect survival, growth, or reproduction. Similarly, L. plumulosus were tolerant of a wide range of sediment grain sizes with only extremely fine grained (e.g., >75% clay) or coarse grained (e.g., >75% sand) material significantly affecting survival, growth, and reproduction. Test performance criteria included control survival (>80%) and reproduction (production of offspring in all control replicates), and response to a reference toxicant test with cadmium chloride in a control chart format.
๐ SIMILAR VOLUMES
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 est