In using WRiMS, users need to consider possible species misidentifications in the sources, and that for some species it is uncertain which is their native and introduced ranges. Whether a species is ‘invasive’ can vary between locations and over time at a particular location.
In 2008-2009 the IUCN Invasive Species Specialist Group (ISSG) worked on a project, within the framework of the Ocean Biogeographic Information System (OBIS), that developed an annotated dataset of marine introduced and invasive species for the World Register of Marine Species (WoRMS) in order to flag species on the register as "alien and invasive species".
Both online databases and publications were consulted with an aim to achieve global coverage. They include:
In addition to biological status (represented as occurrence, provenance and invasiveness), annotations included higher taxonomy, origin of species, introduced location, as well as (where available) information on the date of first record/introduction and pathway of introduction.
In 2013-2014, ISSG worked with the Flanders Marine Institute (VLIZ) on a data collection project developed within the framework of the Biology Project of the European Marine Observation and Data Network (EMODnet) to complete trait information related to "invasiveness". The dataset submitted in 2009 was updated using additional data and information from online databases such as:
The terminology and definitions to describe occurrence, provenance and invasiveness have been revised and expanded. Additionally, any available information on abundance, pathways of introduction and spread, evidence of impacts on biodiversity were documented. The geographic coverage of this dataset is global. Focus was placed on documenting authoritative information on marine species introductions in the recognized marine bio-invasion hotspots.