When that feature is weakened by El Nino, a regime shift from
 anchovies to sardines occurs in this ecosystem.
An animal who shares a name with this place is the jumbo flying squid, Dosidicus gigas, and Elliot's
 storm-petrel is found only in this oceanic system. Andrew Bakun hypothesized that the class this system
 shares with three others would experience an increase in activity due to global warming, and the Guanay
 cormorant feeds mainly on fish found in this system. One important feature of this current is due to trade
 winds causing divergent Ekman transport. When that feature is weakened by El Nino, a regime shift from
 anchovies to sardines occurs in this ecosystem. Southerly trade winds cause this current to upwell
 year-round at its northern extent. For 10 points, name this large marine ecosystem, an eastern boundary
 current lying off the west coast of South American that is the most productive in the world.
An animal who shares a name with this place is the jumbo flying squid, Dosidicus gigas, and Elliot's
 storm-petrel is found only in this oceanic system.
{Humboldt} Current [or {Peru} Current; prompt on "{Eastern Boundary Currents}"]