The first Term of Reference for SCOR WG157 (MetaZooGene) was to create an open-access web portal for DNA barcodes of marine zooplankton.   This portal was to include a reference database (containing a compilation of quality-checked, marine zooplankton COI barcodes) and a barcode atlas (summarizing available species COI barcoding coverage for all the major zooplankton taxonomic groups, reported by ocean or region).

The MetaZooGene "Reference Database" and "Barcode Atlas" were later joined together into a single online product called the MetaZooGene Atlas and Database, or MZGdb.   The biological content of MZGdb has been expanded and now includes zooplankton, benthic invertebrates, fish, marine mammals, and phytoplankton (aka microbes and protists).   The molecular content has also been expanded, and now includes COI, 12S, 16S, 18S, and 28S.

The MZGdb summarizes the presence and barcoding status of major marine fauna and flora groups and species, reported-by geographic regions, oceans, and seas (e.g., "North Atlantic pteropods", "Arctic pinnipeds", "Mediterranean Sea decapods").   The MZGdb also lets the user download data from any of these taxonomic/geographic subsets, which can help reduce sequence matching and processing times.   For example, why use a massive global reference database containing two million+ sequences from "all" organisms (trees and butterflies) when you need to identifying marine plankton or perhaps only "North Sea copepods"?