Chlorophyll-a distribution and associated oceanographic conditions in the upwelling region off northern Chile during the winter and spring 1993

Community metabolism, phytoplankton size ­structure and heterotrophic prokaryote production in a highly productive upwelling zone off northern Chile

“…The cross-shelf vertical structure of temperature and salinity shows that verti- cal stratification is strongest in summer and weakest in winter . In addition, studies of the autotrophic community structure carried out in coastal areas off northern Chile have demonstrated that both phytoplankton abundance and species composition vary seasonally (Herrera & Escribano 2006) and that chl a concentrations in the water column are higher in spring (Morales et al 1996) than in winter (Thiel et al 2007). Nevertheless, our comparison of summer and winter GPP did not show marked seasonality; rather, high integrated GPP values occurred during periods of maximal intensification of wind-driven upwelling (summer, GPP = 9.3 g Cm ; present study).…”

Desmotersia levinae, a new genus and new species of free-living nematode from bathyal oxygen minimum zone sediments off Callao, Peru, with discussion on the classification of the genus Richtersia (Chromadorida: Selachinematidae)

“…In this region the HCS exhibits a thin but intense midwater oxygen minimum layer, which is a major source of upwelled water. This layer is generally associated with the equatorial subsurface water mass (Morales et al 1996); the most hypoxic portion intercepts the seafloor at bathyal depths.…”

Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

“…At greater depths biomass values are negligible due to an extended zone in which the oxygen concentration is equal or lower than 0.5 ml l ¡1 (oxygen minimum zone-OMZ; Ramorino and Muñiz 1970;Levin 2003;Gallardo et al 2004;Escribano et al 2004). The oxygen minimum layer is typically shallow in the coastal area oV northern Chile (Morales et al 1996;Escribano et al 2002Escribano et al , 2004 with an upper boundary, e.g. at 42 m during the austral summer 2000 (Giraldo et al 2002) and between 20 and 40 m during spring 1996 (Escribano and Hidalgo 2000).…”

“…This oceanographic pattern can be aVected by the large-scale El Niño Southern Oscillation (ENSO) (e.g. Taraba 1959;Brandhorst 1971;Navea and Miranda 1980;Fonseca 1989;Arntz and Fahrbach 1991;Fuenzalida 1992a, b;Morales et al 1996;Gonzalez and Marín 1998;Strub et al 1998;Escribano 1998;Ulloa et al 2001;Arntz et al 2006). Monitoring the sea surface temperature oV Chile and Peru has illustrated that ENSO shows an interannual climate oscillation between warm phases (El Niño: EN) and enhanced cold phases (La Niña: LN).…”