Twelve sampling campaigns from a monitoring program performed
in the study area between 2005 and 2012 were selected,
and were classified by their ENSO status in Niño/Niña/neutral,
using the Southern Oscillation Index (SOI) values (Kiladis and van
Loon, 1988) provided by the Argentinean meteorological service
(Servicio Meteorológico Nacional, www.smn.gov.ar).