Aquatic Disposal Field Investigations, Columbia River Disposal Site, Oregon. Appendix C. The Effects of Dredged Material Disposal on Benthic Assemblages.
Abstract
The objectives of this study were to identify and determine the significance of physical, chemical, and biological factors that govern the rate at which open-water dredged material disposal sites are colonized by benthic assemblages. In the macrobenthic areal baseline, 5 assemblages and 13 species groups were found. The distribution, community structure, and seasonal constancy of these assemblages were related to the distribution of sediments and organic matter, the stability of sediments, and changes in sediment characteristics due to the deposition of fine-grained material from the Columbia River. The deposition of dredged material significantly increased diversity and evenness values and reduced the density of macrofauna. Of the 33 most abundant species, 11 species had significantly lower abundances at stations exposed to direct dredged material deposition. The effects of dredged material disposal on benthos were probably related to direct burial of benthos and changes in sediment characteristics and not increased turbidity from the disposal operation or introduction of pollutants or organic matter.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1977
- Accession Number
- ADA054561
Entities
People
- Andrew G. Carey Jr.
- Michael Donald Richardson
- William A. Colgate
Organizations
- Oregon State University