详情

原文传递 LONG-TERM IMPACT OF DREDGED MATERIAL, AT TWO OPEN-WATER SITES: LAKE ERIE AND ELLIOTT BAY; EVALUATIVE SUMMARY

题名：	LONG-TERM IMPACT OF DREDGED MATERIAL, AT TWO OPEN-WATER SITES: LAKE ERIE AND ELLIOTT BAY; EVALUATIVE SUMMARY
作者：	Henry E. Tatem
关键词：	Dredged material--Lake Erie (LC) Dredged material--Elliott Bay (Wash) (LC)
摘要：	Dredged material disponsal sites in Lake Erie and Elliott Bay were studied in 1975-1976. This report describes results of studies conducted at these locations in 1979-1980, 3 or 4 years after the disposal events The Lake Erie study area included two control and three disposal sites ,sampled once in 1979. Disposal sites contained more gravel and sand compared to control areas. Numerous macrofaunal and meiofaunal animals were found at all of the sites. In general, control sites contained more macrofaunal animals and species while the disposal sites were richer in meiofauna .Substrate type and variety, which was influenced by the disposal events ,determined which animals were found where, None of the sites were devoid of animals and there was no indication that sediment contaminants affected benthic communities at the disposal sites. There were no differences in mercury or cadmium concentrations in sediment samples from the various sites. Samples taken at the Elliott Bay disposal site revealed that the disposal mound, created in 1975-1976, was still present and had stabilized physically and chemically The mound area contained more animals than the surrounding bottom areas. Bivalves and polychaetes were the dominant animals found at the disposal site. The numbers of these animals at the site increased from 1976 to 1979-1980.Sediment at the center of the disposal site contained polychlorinated biphenyls (PCB); howerer, other areas of Elliott Bay, removed from the dredged material mound, also contained PCB at concentrations similar to those observed at the site. Some animals taken from the disposal mound contained PCB at levels slightly higher than sediment levels which were in the 2.0-to 3.0 –ppm range.
报告类型：	科技报告