DEVOTES releases the European Seas Keystone Species Catalogue and the Keystone Review Report

The DEVOTES Task 6.1.3. team have released their Keystones Catalogue with accompanying Report

The Catalogue is a database with 844 entries concerning 210 distinct species and 19 groups classified by major habitats in the Baltic Sea, North East Atlantic, Mediterranean, Black Sea (EU Regional Seas) and Norwegian Sea (Non-EU Sea). Information is detailed on their type, importance, size/abundance/distribution, habitat and region, with 164 cited references relating to the species. The keystones in the catalogue are sourced from models, by use as indicators, by published work (e.g. on traits and interactions with other species), and by expert opinion based on understanding of systems and roles of species/groups.

The accompanying report contains the meta-analysis of the catalogue, and a rich contextual review. The review covers a wide variety of keystone issues. Gaps in catalogue coverage and expertise are analysed at the habitat and regional sea level, within the MSFD biodiversity component groups, and in light of knowledge and outputs from ecosystem models (Ecopath with Ecosim).

Keystone species

When is a keystone a keystone?

The understanding of keystones is discussed as to when a species may be a dominant, key or keystone with respect to the definition, what separates a keystone predator and keystone prey for mid-trophic range species, and how context dependency makes a species a keystone.

Keystone alien invasive species are reviewed and the use of keystone species model outputs investigated. In the penultimate sections of the review, the current level of protection on keystone species and the possibilities for a keystone operational metric and their use in management and in Good Environmental Status assessments for the Marine Strategy Framework Directive are discussed.


The final section highlights the one keystone species and its interactions not covered in the catalogue but with the greatest impact on almost all marine ecosystems, Homo sapiens.

Number keystone species

Number of keystone species per major biological component and Marine Strategy Framework Directive region

Number of species

Overall number of species distributed in the different habitat types and for each regional sea. Note different scales between Total and Regional Seas

Keystones Catalogue
Smith C, Papadopoulou N, Sevastou K, Kiriakopoulou N, Teixeira H, Katsanevakis S, Piroddi C, Beauchard O, Franco A, Fürhaupter K, Chenuil A, David R, Feral J-P, Ramsvatn S, Cochrane S, Zaiko A, Moncheva S, Stefanova K, Churilova T, Kryvenko O, Tsagarakis K, Simboura M, Karachle P, Kalogirou S, Markantonatou V (2014) List of available keystone species for possible use in GES assessment of Descriptors 1, 2, 4 and 6 of the MSFD. DEVOTES Project, Deliverable 6.1 “Report on identification of keystone species and processes across regional seas”, Annex 2.

Keystone Review
Smith C, Papadopoulou N, Sevastou K, Franco A, Teixeira H, Piroddi C, Katsanevakis S, Fürhaupter K, Beauchard O, Cochrane S, Ramsvatn S, Feral J-P, Chenuil A, David R, Kiriakopoulou N, Zaiko A, Moncheva S, Stefanova K, Churilova T, Kryvenko O (2014) Report on identification of keystone species and processes across regional seas. Deliverable 6.1, DEVOTES Project. 105 pp + 1 Annex.