Accession Number:

ADA058442

Title:

Aquatic Disposal Field Investigations, Duwamish Waterway Disposal Site, Puget Sound, Washington. Appendix F. Recolonization of Benthic Macofauna Over a Deep-Water Disposal Site.

Descriptive Note:

Final rept.,

Corporate Author:

ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS

Personal Author(s):

Report Date:

1978-06-01

Pagination or Media Count:

461.0

Abstract:

Seasonal monitoring of benthic macrofauna and fish stomach contents was conducted over a deep 64 m experimental disposal site in the Duwamish River-influenced portion of Elliott Bay, Puget Sound, Washington. Triplicate samples were collected during a 9-month sampling period within the disposal site and at four reference stations, two from the greater east side and two from the lesser west side river-influenced portions of the bay. The areal extent of the disposed dredged material was discernible from the changes in sediment composition was well as changes in biomass density and species composition of the benthic community. During the 9-month postdisposal sampling period recovery was not complete. Three recolonizing phases were recognized in the succession of the benthic fauna. Phase I was characterized by the immediate recolonization by fish and shrimp, migration of predisposal occupants to the surface of the deposit, and migration of species into the disposal area from adjacent habitats. Phase II was represented by a summer recruitment period of opportunistic species and annuals onto the disposal site, and Phase III was distinguished by an increase in predatory worms and subsequent decline in opportunistic species. The last phase of the succession was not observed. Recovery of many of the nonbenefited annuals and climax species was not observed during the 9-month sampling period.

Subject Categories:

  • Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE