Increased recruitment of northeast Pacific barnacles during the 1997 El Nino

Recruitment of intertidal barnacles was markedly higher in May-September 1997, just after the apparent onset of El Nino conditions in the waters off California, than over the same period during the previous year. This increase was geographically broad, spanning five degrees of latitude, and was unusually large, relative to interannual differences in barnacle recruitment previously documented for this region. Increased onshore transport associated with El Nino events probably caused high recruitment in 1997. This explanation accords with the findings of previous, smaller scale studies in central and northern California and indicates that oceanographic transport anomalies associated with El Nino can strongly affect benthic communities in the northeast Pacific.