Ecotoxicity assessment of natural attenuation effects at a historical dumping site in the western Baltic Sea.
During the late 1950s and early 1960s of the past century, industrial waste material highly enriched in various contaminants (heavy metals, PAHs) was dumped in the inner Mecklenburg Bay, western Baltic Sea. Large-scale shifts in the spatial distribution of heavy metals in surface sediments were mapped by geochemical monitoring in the mid-1980s and 12 years later in 1997. A further study in 2001 was designed to investigate the small-scale spatial distribution of contaminants inside, on top of, and around the historical dumping ground and to examine possible effects to benthic organisms (Arctica islandica, microbiological toxicity tests). The site is located within an area characterized by a discontinuous deposition of fine sediments, but net sedimentation rate of about 3mm/y led ultimately to a gradual coverage of the dumped material. During the first decades after the dumping, about half of the originally dumped material was already spread over the surrounding area as a result of sediment dynamics and re-suspension processes. Recent sediments of the historical dump site are still significantly enriched in heavy metals and PAHs. Microbiological toxicity test results were positive, though uptake of contaminants in mussels was found to deviate only slightly from that of a non-contaminated reference station due to a gradual dilution and decrease in bioavailability of the contaminants.
Leipe
Thomas
T
Institute of Baltic Sea Research, Seestrasse 15, D-18119 Warnemünde, Germany. thomas.leipe@io-warnemuende.de
Kersten
Michael
M
Heise
Susanne
S
Pohl
Christa
C
Witt
Gesine
G
Liehr
Gladys
G
Zettler
Michael
M
Tauber
Franz
F
D000818:Animals; D001419:Bacteria / Q000187:drug effects*; D049872:Bivalvia / Q000378:metabolism*; D002849:Chromatography, Gas; D017377:Diatoms / Q000187:drug effects*; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis* / Q000633:toxicity; D019015:Geologic Sediments / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis / Q000633:toxicity; D009659:North Sea; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D013052:Spectrometry, X-Ray Emission; D013054:Spectrophotometry, Atomic; D018675:Toxicity Tests
D004785:Environmental Pollutants; D019216:Metals, Heavy; D011084:Polycyclic Aromatic Hydrocarbons