small depth of the coastal area, which allows a re-stocking by the bottom nutrient pool.
Conclusion
Altogether, thc collected data sets show that the model reproduces the
regional structure of phytoplankton dynamics. This model shows that
river nutrient inputs intensify the productivity in the coastal areas. Even
after the spring production, a narrow band with increasing biomass towards coast is observed. The mean primary production during spring of
the stratified area is 1.4 gC.m
2 .d
1 for the coastal areas, while the mean
production in more oceanic waters is less than 0,5 gC.m'-.d' 1 . This threedimensional model is an efficient tool for analysing phytoplankton
dvnamics, nutrient transport and primary productivity? in the bay of
Biscay.
Bib/iographic references
Biggs D.C., Sanchez L.L, 1997. Nutrient enhanced priman’ productivity
of the Texas-Louisianna continental shelf. J. Mar. Syst., 11(3-4), 23724C
Cerco C.F., Cole T., 1993. Three-dimensional eutrophication model of
Chesapeake bay.J. Environ. Eng., 19(6), 1006-1025.
Chapelle A., Lazure P., Ménesguen A., 1994. Modelling eutrophication
events in a coastal ecosystem. Sensitivitv analysis. Estuar. Coast. Shelf
Sci., 39, 529-548.
Chen C, Wiesenburg D.A., Xie L., 1997. Influences of river discharge
on biological production in the inner shelf; a coupled biological
and physical model of the Louisiana-Texas shelf. J. Mar. Res., 55(2),
293-320.
Dippner J.W., 1993. A frontal-resolving model for the German Bight.
Cont. Shelf Res., 13(1), 49-66.
Dmon J.N., Loyer S., Gohin F., (in press). The contribution of ocean
colour sensors for the scaling of pigment patterns in coastal waters:
comparison with an ecosystem model of the French Adantic shelf.
Mar. Ecol. Progr. Ser.
Harding L.W. (Jr), Petry F.S., 1997. Long-term increase of phytoplankton biomass in Chesapeake bay, 1950-1994. Mar. Ecol. Progr. Ser.,
157, 39-52.
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