Physico-chemical and biological features of a drilling site in the North Sea, 1 year after discharges of oil-contaminated drill cuttings
Daan, R.; van het Groenewoud, H.; de Jong, S.A.; Mulder, M. (1992). Physico-chemical and biological features of a drilling site in the North Sea, 1 year after discharges of oil-contaminated drill cuttings. Mar. Ecol. Prog. Ser. 91(1-3): 37-45
In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630; e-ISSN 1616-1599, meer
Ook verschenen in:Stebbing, A.R.D.; Dethlefsen, V.; Carr, M. (Ed.) (1992). Biological effects of contaminants in the North Sea: Results of the ICES/IOC Bremerhaven Workshop. Marine Ecology Progress Series, 91(1-3). Inter-Research: Amelinghausen. 361 pp., meer
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| Trefwoorden |
Environmental impact
Pollution > Oil pollution
Pollution > Sediment pollution
Surveys > Environmental surveys > Pollution surveys
ANE, Noordzee [Marine Regions]
Marien/Kust |
| Auteurs | | Top |
- Daan, R., meer
- van het Groenewoud, H.
- de Jong, S.A., meer
- Mulder, M.
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| Abstract |
In the framework of the Paris Convention for the prevention of marine pollution, the Dutch government initiated a research programme on environmental effects of discharges of contaminated drill cuttings from platforms in the North Sea. Chemical analyses of the sediment over a transect in the residual current direction revealed a clear gradient in contamination levels, with oil concentrations ranging from 250 to 450 mg kg super(-1) dry sediment within 250 m and gradually decreasing to <20 mg kg-1) beyond 750 m. Barium concentrations showed a similar pattern. Subtle biological effects, indicated by the absence of a very sensitive species (Montacuta ferruginosa), were found as far as 2 km from the discharge site. Abundance patterns of 2 other sensitive species (Harpinia antennaria and Callianassa subterranea) suggested environmental stress to occur up to 1 or 2 km. Within 750 m from the discharge site an increasing number of species, including the dominant Amphiura filiformis, appeared to decrease in abundance, successively resulting in a reduced total macrofauna abundance and species richness. Typical opportunistic species were observed more frequently only within a radius of 250 m. An alternative measure of diversity ('relative macrofauna abundance') was introduced and its merits are discussed. |
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