|PCB's, organochrlorine pesticides and mercury in the lower trophic levels of the Indian sector of the Antarctic marine ecosystem|
Joiris, C.; Overloop, W. (1989). PCB's, organochrlorine pesticides and mercury in the lower trophic levels of the Indian sector of the Antarctic marine ecosystem, in: Caschetto, S. (Ed.) Belgian scientific research programme on Antarctica: scientific results of phase I (10/1985-01/1989): 1. Plankton ecology. pp. 07/1-29
In: Caschetto, S. (Ed.) (1989). Belgian scientific research programme on Antarctica: scientific results of phase I (10/1985-01/1989): 1. Plankton ecology. Science Policy Office of Belgium: Brussel. 158 pp., more
|Authors|| || Top |
- Joiris, C., more
- Overloop, W.
Making use of the expertise acquired during more than one decade in the North Sea in the fïeld of ecotoxicology (transfer- and accumulation mechanisms of stable pollutants). we started a comparable study of the Antarctic ecosystems. The aim of this study is to test the generality of the concepts developped for the North Sea systems. and to obtain more information on Antarctica. where fragmentary data only are availahle, in order to increase the knowledge on the global distribution of stable pollutants and of their transfer and accumulation mechanisms, and to provide the essential basic information needed for controlling pollution on a large scale.From January 3d to February 27th. 1987, we participated to the INDIGO 3 cruise on board the French R. V. Marion Dufresne. The cruise track covered the Indian sector of the Southern Ocean between latitudes 38°S to 67°S and longitudes 18°E to 84°E. PCBs concentration in particulate matter (mainly phytoplankton) appears to be high: 0.75 µg/g dry weight, a level similar to the one of temperate zones. No significant geographical difference was detected. In order to interpretate such results correctly, it is however necessary to express them in other units like per volume of seawater and per lipid weight. Per water volume, the contamination seems more constant, but lower than in northern temperate zones. The explanation is that the Antarctic ecosystems are less contaminated than temperate regions - as expected - but that the very low biomasses present cause high levels per unit of biomass. These results confirm the necessity of using different systems of units. Due to the heterogeneity of the netplankton samples (variable phytoplankton/zooplankton composition), the contamination is compared both with particulate matter and zooplankton of temperate zones. The relative contribution of the zooplankton to the contamination level of the samples can however not be determined with precision. The levels of organochlorine pesticides such as lindane. dieldrin. heptachlorepoxide and aldrin are either low, found as traces or not detected at all. DDT and DDE were the lowest of all detected organochlorines. High DDT /DDE ratios reflect the recent use of these pesticides in southern developping countries. The total mercury contamination was also determined and provided results leading to similar conclusions as for PCBs.