Accession Number : ADA308069

Title :   Environmental Effects of Dredging. Grain Size and Total Organic Carbon Effects on Benthic Organisms,

Descriptive Note : Technical note,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS

Personal Author(s) : Sims, Jerre G.

PDF Url : ADA308069

Report Date : MAR 1996

Pagination or Media Count : 10

Abstract : The purpose of this technical note is to document the effects of grain size and total organic carbon (TOC) on benthic organisms and evaluate those effects in terms of their potential to confound the results of dredged material bioassays. Sediment toxicity tests must be able to assess the effects of sediment-associated contaminants without the influence of nontreatment factors (that is, sediment, grain size, sediment TOC, ammonia toxicity, etc.). While nontreatment factors can affect survival in short-term acute toxicity tests, there is greater potential for such factors to affect end points measured in longer term chronic tests. Exposure in chronic bioassays generally represents a significant portion of an animal's life history and often encompasses one or more sensitive life-history stages (larval, juvenile, reproductive adults). In addition, end points measured in such tests are of a more subtle, sublethal nature (for example, growth and reproduction) and can be significantly influenced by small variations in exposure conditions (differences in grain size, TOC, etc.). p1

Descriptors :   *TOXICITY, *GRAIN SIZE, *CARBON, *ENVIRONMENTAL IMPACT, *ORGANIC MATERIALS, *AQUATIC ORGANISMS, *DREDGED MATERIALS, *SEDIMENTS, TEST AND EVALUATION, EXPOSURE(GENERAL), TEST METHODS, SURVIVAL(GENERAL), AMMONIA, ANIMALS, LIFE(BIOLOGY), BIOASSAY, OCEANOGRAPHY, REPRODUCTION(PHYSIOLOGY).

Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Biological Oceanography
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE