Arctic Ocean Diversity
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The Arctic Register of Marine Species (ARMS)

Where is the Arctic?

ARMS scopeNumerous definitions exist for “what is the Arctic”, largely based on political boundaries. For the purposes of ArcOD’s effort, we define the regions based on biologically relevant physical criteria: areas within the seasonally-averaged 2 °C surface isotherm or the median maximum sea-ice extent (whichever is greater) as shown in the figure. For deep-sea pelagic and benthic communities cold Arctic water occurs through the entire Norwegian Sea bounded largely by a deep-sea ridge running form Greenland, through Iceland and the Faroe Island to southern Norway. The boundaries should not be considered absolute, because they shift seasonally, and indications are they have been shifting over the past century. Seasonally, there are large influxes of species from outside of the Arctic into it as part of the cycle that has existed for centuries. Larger more mobile species migrate back out, but for many invertebrates transport into the Arctic is a one-way path that effectively removes them from the species’ reproductive pool.

About the register

Despite more then a century of study, there is no pan-Arctic list of all the species that living in the Arctic Ocean and its adjoining Sea. Until now the most complete list has been the 2001 List of species of free-living invertebrates of Eurasian Arctic Seas and adjacent deep waters, edited by Boris Sirenko from the Zoological Institute in St. Petersburg, Russia. Using this as a starting point, we have added the known marine vertebrates, and species within the databases currently assembled by ArcOD, and aligned them with the World Register of Marine Species (WoRMS) who maintain such registers

The list currently includes all multicellular animals. We are now turning our attention to adding the phytoplankton, macrophytes and eucaryotic protists into the next release, as well as updates to the list based on ArcOD's underway synthesis activities. The next version will also include information on habitat (benthic or pelagic, depth preferences).


Like all such lists, it is an evolving process as new species are added, some are shown to be invalid (or misidentified), and some species are recognized as synonymous with other names by ArcOD and WoRMS taxonomic editors. The ARMS editorial board maintains these registers but is aware that they may not be complete and may contain errors. The board cannot be held responsible for any errors or misuse of data contained in these registers. Comments from our users are more than welcome, so if you come across incorrect or incomplete information, or you are willing to contribute to this initiative, please contact


Usage of data from the Arctic Register of Marine Species in scientific publications should be acknowledged by citing as follows:

  • Sirenko, B.I.; Clarke, C.; Hopcroft, R.R.; Huettmann, F.; Bluhm, B.A.; Gradinger, R. (eds) (2024). The Arctic Register of Marine Species (ARMS) compiled by the Arctic Ocean Diversity (ArcOD). Accessed at on 2024-04-14
If the data from the Arctic Register of Marine Species constitute a substantial proportion of the records used in analyses, the chief editor(s) of the database should be contacted. There may be additional data which may prove valuable to such analyses.

Individual pages are individually authored and dated. These can be cited separately: the proper citation is provided at the bottom of each page.

Editorial Board

The ARMS editorial board consists of taxonomic and data management experts. It relies heavily on the established board of editors to establish the validity of species. Distribution records for names listed in the ARMS database have been or are being checked and updated by ARMS taxonomic experts. The ARMS editorial board does not directly have the authority to modify taxonomic information stored in WoRMS; however, the editors may collaborate with WoRMS taxonomic editors to effect changes.

Executive Editors

Bodil A. Bluhm, The Arctic University of Norway; Department of Arctic and Marine Biology
Ksenia N. Kosobokova, Shirshov Institute of Oceanology, Moscow
Rolf Gradinger, Institute of Marine Sciences, University of Alaska Fairbanks
Russell R. Hopcroft, Institute of Marine Sciences, University of Alaska Fairbanks
Falk Huettmann, Institute of Arctic Biology, University of Alaska Fairbanks
Catherine W. Mecklenburg, California Academy of Sciences
Boris I. Sirenko, Zoological Institute, Russian Academy of Sciences, St. Petersburg
Igor S. Smirnov, Zoological Institute, Russian Academy of Sciences, St. Petersburg

Data management

Cheryl Clarke-Hopcroft, Institute of Marine Sciences, University of Alaska Fairbanks
Russell R. Hopcroft, Institute of Marine Sciences, University of Alaska Fairbanks
Bart Vanhoorne, VLIZ, Flanders Marine Institute, Oostende, Belgium

ArCOD partners
ARMS website and database developed and hosted by VLIZ · Page generated 2024-04-14 GMT · contact: