Data collation and quality control

Prior to each workshop, MBU team members compile and enter relevant data for each species to be assessed into the IUCN online database, the Species Information Service (SIS). The necessary data include:

  • Taxonomy
  • Distribution
  • Population status
  • Habitats and ecology
  • Major threats
  • Use and trade
  • Conservation measures

The majority of the information comes from peer-reviewed, published literature, including species descriptions, surveys, check-lists and experiments. Additional information from grey literature, including reports and field guides, is also incorporated. Finally, personal observations and unpublished data from the workshop participants is included as available.

In the months following a workshop, accounts must be edited, finalized, and reviewed. This process involves the retrieval of important references and additional information that may have been obtained after the workshop, ensuring established IUCN documentation standards are met, and the completion of recommended distribution map alterations. Revised species accounts and maps are once again reviewed by the expert participants.

Finally, each assessment must be evaluated independently by both a content reviewer (an expert on the species) and a technical reviewer (an expert on the application of the IUCN Categories and Criteria). A Red List Authority on the species group or a member of the MBU team is assigned the job of technical reviewer, while the content reviewer is typically a scientific expert that did not participate in the workshop itself. Once this process is complete, assessments are submitted for final review by the IUCN Red List Unit.

Mapping marine species

Associated with each species assessment is a digital distribution map. These maps are developed using the best available data on the known points, countries or regions of occurrence, then fully vetted by taxonomic and regional scientists. Maps are generated based on species-specific depth and habitat constraints. For standardization and visualization purposes, maps of coastal, nearshore species are clipped to a base layer of 200 m depth or 100 km from the coastline. Pelagic and bathydemersal species are digitized by hand following general bathymetric contours representing the known or inferred limits of the species depth distributions.

Global vs. regional assessments

Although the vast majority of our work to date has focused on global IUCN Red List assessments, there is increasing interest in sub-global scale projects, where higher resolution data, including those on distribution and population trends, can be utilized.

As of 2015, we have completed three regional-scale projects: European marine fishes, marine bony shorefishes of the Gulf of Mexico, and marine bony fishes of the Persian/Arabian Gulf.


Frogfish. Photo Credit - Will Turner Upeneus oligospilus. Photo Credit - Friedhelm Krupp