Efectos microbiológicos producidos por un evento de surgencia costera en Chile central

Abstract

An upwelling is an oceanographic phenomenon which produces a nutrients enrichment of euphotic zones resulting in a phytoplankton bloom crucial for productivity in many coastal zones in Chile. In this research we present information concerning the microbiological effect of an upwelling event. In regard to other studies performed in Chile, we include a novel variable: the changes in virus concentrations in relation with the upwelling and the abundances of phytoplankton and bacterioplankton. The samples were collected at Valparaiso bay (32°57'S; 71°34'W) during spring 2006. Species composition and high phytoplankton concentrations are according with an upwelling event. After the upwelling, phytoplankton, bacteria and virus increased 24, 6 and 15 times, respectively. Shortly after, phytoplankton and bacterioplankton declined but, in contrast, virus increased 5 more times. This latter is consistent with the idea that virus is important, at least, in the decline of the bacterioplankton concentration.