  Intensification and poleward expansion of upwelling favourable winds have
been predicted as a response to anthropogenic global climate change and have
recently been documented in most Eastern Boundary Upwelling Ecosystems of the
world. To identify how these processes are impacting nearshore oceanographic
habitats and, especially, long term trends of primary productivity in the
Humboldt Upwelling Ecosystem (HUE), we analysed time series of sea level
pressure, wind stress, sea surface and atmospheric surface temperatures, and
Chlorophyll-a, as a proxy for primary productivity, along 26{\deg} - 36{\deg}
S. We show that climate induced trends in primary productivity are highly
heterogeneous across the region. On the one hand, the well documented poleward
migration of the South Pacific Anticyclone (SPA) has led to decreased spring
upwelling winds in the region between ca. 30{\deg} and 34{\deg} S, and to their
intensification to the south. Decreased winds have produced slight increases in
sea surface temperature and a pronounced and meridionally extensive decrease in
surface Chlorophyll-a in this region of central Chile. To the north of 30{\deg}
S, significant increases in upwelling winds, decreased SST, and enhanced
Chlorophyll-a concentration are observed in the nearshore. We show that this
increased in upwelling driven coastal productivity is probably produced by the
increased land-sea pressure gradients (Bakun's effect) that have occurred over
the past two decades north of 30{\deg} S. Thus, climate drivers along the HUE
are inducing contrasting trends in oceanographic conditions and primary
productivity, which can have far-reaching consequences for coastal pelagic and
benthic ecosystems and lead to geographic displacements of the major fisheries.
