FLUXMANCHE radiotracers measurements: A contribution to the dynamics of the English Channel and North Sea

Abstract

From 1986 to 1992, 125 Sb released by La Hague Fuel Reprocessing Plant, was used to study the transfert of waters from mid-Channel areas towards the Dover Strait. Since 1990 these investigations have been part of MAST 53 FLUXMANCHE programme with repeated measurements on the Dover Strait transect. The discussion of the results will take into consideration new informations given by the hydrodynamic model elaborated in the frame of FLUXMANCHE: knowledge of the monthly fluxes of water in the Strait of Dover and simulation of the 125 Sb activities, week by week, in the waters flowing in this aera. It is shown that solubles radionuclides introduced into the central Channel are transfered towards the Dover Strait in a time which varies between 4 and 7 months, depending on the route taken.

High spatial variability of phytoplankton assessed by flow cytometry, in a dynamic productive coastal area, in spring: The eastern English Channel

“…In the present study, three waters masses were defined in the EEC waters along the 315 kilometres explored within the DYPHYMA cruise, based on salinity and temperature. High salinity values were observed within water mass W3 (Fig.3), which should correspond to Atlantic waters which are channelled towards the North Sea (Quisthoudt et al, 1987a), as was also stated by Salomon and Breton (1993) and Guegueniat et al (1995). French EEC coastal waters (W1 and W2) can be defined as a coastal ecosystem receiving large freshwater inputs from local and remote rivers.…”

Movement of adult edible crab (Cancer pagurus L.) at the Swedish West Coast by mark-recapture and acoustic tracking

“…have been presented: inshore migration for moulting, mating (females and males) and spawning and offshore hatching migration (Diamond and Hankin, 1985), migrations toward exposed area for spawning (Smith and Jamieson, 1991), mating migration or pre-hatching emigration to avoid osmotic stress (Orensanz and Gallucci, 1988) of C. magister, feeding migration in C. novaezelandiae (Chatterton and Williams, 1994) and female migrations related to moulting and mating in C. pagurus at the north east coast of Scotland and England (Mason, 1962;Edwards, 1979). The extensive westerly or south-westerly migrations in the English channel (Bennett and Brown, 1983;Latrouite and Le Foll, 1989) are against the prevailing easterndirected Channel current (Dahlgaard, 1995;Guegueniat et al, 1995). Bennett and Brown (1983) point out that this may be an offshore migration towards grounds suitable for spawning and/or counteracting larval drift, and therefore having consequences for the replenishment of eastern stocks in the Channel.…”

The English Channel: Contamination status of its transitional and coastal waters

“…Long range aquatic transport has been identified using measurements showing the migration of 125 Sb from the French nuclear reprocessing plant at La Hague into the North Sea (Guéguéniat et al, 1995(Guéguéniat et al, , 1997. In 1993, dissolved 99 Tc activity concentrations were in the range 0.19-0.93 mBq L À1 , with the highest values being to the east of La Hague (McCubbin et al, 2002).…”