||Nouvelles observations sur l'eutrophisation du Golfe du Lion par les apports nutritifs rhodaniens
||Coste A, Cadenes A, Minas H
||Production et relations trophiques dans les ecosystemes marins. Yalta 27 Octobre-2 Novembre 1984
||Actes de colloques. Ifremer. Brest [ACTES COLLOQ. IFREMER.]. 1984
||France, Rhone R., Nutrient cycles, Primary production, River discharge, Nutrients (mineral), Eutrophication
||During the cruise EURHOGLI (Eutrophication by the Rhone of the Gulf of Lion) of the R.V. Le Noroit , a grid of stations covering the dilution area of the Rhone River has been carried out two times with a time interval of about two weeks. An exceptional growth during the two months preceding the cruise, has produced an important dilution effect over a wide spread areas. The absence of nutrients demonstrates their general consumption by biological activity. The tracer properties of the nutrient can be observed only in a small area near the mouth of the river. Nutrients are becoming the tracer of this dilution, and a great development of chlorophyll associated to this same area, show that nearly all the biological activity of nutrient assimilation is concentrated in the narrow surface layer. Such a situation proves the absence of downward mixing effect due to the wind. Determinations of nutrients in the waters show a strong increase of the concentration during the last 20 years; this increase has an anthropogenic origin.