The World Ocean Database 2001 (WOD01) is an eight CD-ROM product containing over seven million oceanographic stations. Only one disk (WOD01 disk #1) contains plankton tows, which are co-located with two million other Ocean Station Data (OSD) profiles. These two million profiles are then divided into 648 separate "WMO" files, each one representing a single 10x10-degree latitude-longitude WMO grid box of the world. While this layout was necessary and efficient for the 6.9 million non-plankton records, it makes extracting and accessing the plankton data very difficult. Additionally, the World Ocean Atlas 2001 - Volume 5: Plankton contains maps of the distribution of World Ocean Database 2001 plankton taxonomic groups and one-degree latitude-longitude fields of mean zooplankton biomass. Maps for all-data annual and seasonal compositing periods are presented for bacterioplankton, phytoplankton, protist plankton, zooplankton, and plankton biomass. All-data annual maps are also presented for select taxonomic sub-groups within these major categories (e.g., diatoms, copepods, chaetognaths). One-degree latitude-longitude mean fields of annual zooplankton biomass and annual and seasonal zooplankton carbon mass are also provided. OBIS serves 1,281,125 of these plankton records.