Bacterial abundances and their relationship to iron around the Galápagos Islands, Ecuador

Abstract

In an attempt to characterize the influence of an iron source on bacteria around the Galapagos Islands, bacteria were sampled at the surface and at four different depths from the R/V Thomas G. Thompson during 13-15 January 2006. This project hypothesized that the islands provided some form of iron source for the bacteria. At two stations the total number of bacteria was greatest in the shallow subsurface, where there was a chlorophyll maximum, while at the rest the bacterial concentration was highest at the surface. No distinct cause was found for why this variability among stations occurred. In addition, no significant differences were found among water samples treated with iron or an iron chelator or unamended, suggesting that bacteria around the islands are not strongly influenced by iron availability.