Biological traits analysis is one of the most auspicious approaches to study the ecological functioning in marine ecosystems and provides a mechanistic link to ecosystem processes and properties. We used a Biological trait analysis to examine a dataset of 334 macrofaunal species that were collected at 4 long-term stations in the North Sea between 1969-2011. This data include seventeen biological traits related to life history (e.g. reproductive type) and behavior (e.g. feeding habit) of macrofuna species. In order to include all possible attributes of species, these traits were broken down into seventy-two categories. The affinities of the species to the categories were fuzzy coded with a scoring range of 0 to 3 (0= no affinity, 1= low affinity, 2=moderate affinity and 3=high association of taxon with the trait category). Missing values were supplemented by using information from the species in the nearest taxonomic level. If the affinity of a species to a category was not identified and there was no information available for the evaluation, a score of 0 was given for all the modalities associated with that species.