An almost completed pollution-recovery cycle reflected by sediment geochemistry and benthic foraminiferal assemblages in a Swedish-Norwegian Skagerrak fjord.
During the 20th century Idefjord was considered one of the most polluted marine areas in Scandinavia. For decades it received high discharges from paper/pulp industry, which made it anoxic and extremely polluted by heavy metals and organic contaminants. Today the fjord is close to fulfil a complete pollution-recovery cycle, which is recorded in its sediment archives. Here we report results from five sediment cores studied for TC, C/N, heavy metals and benthic foraminifera. All of the cores have laminations deposited during 1940-1980s and indicative of long-lasting anoxia; high TC and heavy metal content, poor foraminiferal faunas and lack of macrofauna. The upper part of the cores deposited since 1980s shows a gradual pollutant decrease and partial foraminiferal recovery. The majority of foraminiferal species in Idefjord are agglutinated opportunistic and stress-tolerant taxa, which to some extent tolerate hypoxia and are early colonisers of previously disturbed environments. The current study demonstrates a value of benthic foraminiferal stratigraphy as a useful tool in understanding processes driving environmental degradation and recovery of coastal ecosystems.
Department of Earth Sciences, University of Gothenburg, P.O. Box 460, SE 40530, Sweden. Electronic address: irina.asteman@uni.no.
Irina
I
Polovodova Asteman
Department of Earth Sciences, University of Gothenburg, P.O. Box 460, SE 40530, Sweden.
Daniela
D
Hanslik
Department of Earth Sciences, University of Gothenburg, P.O. Box 460, SE 40530, Sweden.
Kjell
K
Nordberg
D059001:Aquatic Organisms; D002244:Carbon / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D063366:Estuaries; D056908:Foraminifera / Q000502:physiology*; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry*; D007220:Industrial Waste; D007856:Lead Radioisotopes / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D009664:Norway; D013548:Sweden; D014874:Water Pollutants, Chemical / Q000032:analysis; D014877:Water Pollution, Chemical / Q000032:analysis*
D007220:Industrial Waste; D007856:Lead Radioisotopes; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D002244:Carbon; D009584:Nitrogen
Bottom-water anoxia; Ecological indicators; Environmental micropaleontology; Heavy metals; Organic pollution; Pulp and paper industry