Autotrophic production, biomass and species composition at two stations across an upwelling front

In early September 1989 persistent southward w ~n d s generated an upwelling region along the Oregon, USA, coast with a front (upwelling front) at its seaward edge. We examine and compare autotrophic production, biomass and species composition in the euphotic zones of 2 stations on either side of this front using a combination of analytical techniques. The upwelling front could be seen in satellite thermal imagery all along the southern Washington and Oregon coasts except where it was obscured by the outflow of the Columbia River. Hydrographic profiles at the seaward station showed a relatively warm and deep surface-mixed layer that was freshened by river water. At the landward station the river's influence was much less, and cold, saline water extended to within 10 m of the surface.