Assessing sea floor functional biodiversity and vulnerability

The marine benthos has been largely studied through the use of response traits that characterise species vulnerability to disturbance. More limited has been the specific use of effect traits that represent other species descriptors and that express ecosystem functions. On the sea floor, the benthos is a key ecosystem-engineering component for which functions can be relevantly derived from effect traits. This study provides a typology of sea floor functions based on an extensive data compilation of effect traits. We classified 812 benthic invertebrate species from the northeast Atlantic by 15 effect traits expressing substratum alteration and habitat creation. Cluster analysis identified 15 species groups that represented various epi- or endobenthic functions. Beyond function-habitat specificity, we show that soft sediment species exhibited broader functional niches in the trait space that increase multi-functionality, and were endowed with rare combinations of traits that expanded the functional extent of the species assemblage. As a consequence, soft sediments can host a higher functional diversity than hard substrata because a wider range of above- and below-substratum activities are possible in soft bottoms. Based on response traits documented for the same species and used to express vulnerability to natural or human-induced disturbance, we then show that vulnerability within sea floor functions can be considerably variable. This can be a consequence of the independence between the evolutionary nature of response traits and the contingent engineering abilities of benthic species through effect traits. The paper provides theoretical and utilitarian clarifications on this trait dichotomy.


Benthic invertebrate, Effect trait, Ecosystem engineering, Ecosystem function, Functional group, Functional diversity, Vulnerability

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239 Mo
Tables S1.1 and S1.2
-749 Ko
Additional methods, including Table S2.1 and Figs. S2.1 & S2.2
5319 Ko
Figs. S3.1–S3.10
93 Mo
Descriptions of the taxonomic and functional compositions of the 15 typological groups
2143 Ko
How to cite
Beauchard Olivier, Thompson Murray S. A., Ellingsen Kari E., Piet Gerjan, Laffargue Pascal, Soetaert Karline (2023). Assessing sea floor functional biodiversity and vulnerability. Marine Ecology Progress Series. 708. 21-43.,

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