Biological trait information for 80 offshore benthic epifaunal invertebrate species from the western and southern ecoregions of South Africa

This dataset consists of the fuzzy coded trait data of 80 macrobenthic epifaunal invertebrate taxa collected during biannual demersal fish stock assessment trawl surveys along the western and southern ecoregion of South Africa. Traits are generally defined as the morphological, life-history and behavioural characteristics of the species present in an assemblage, and can be used to provide insight into ecological processes (e.g. predation, deposit feeding, sediment turnover, etc) which in turn reflects the ecosystem functioning (e.g. productivity, resilience, nutrient cycling, sediment stability, etc). Modalities then refer to the distinct categories or classifications each trait can be divided. For example, the trait “body form” can be divided into modalities such as round, elongated, laterally flattened, dorsally flattened, irregular, etc. In order to conduct further analysis, it was necessary to quantify the biological information collected for each of the 80 epifaunal taxa. However, because certain taxa might possess more than one modality for a particular trait, a scoring system called “fuzzy coding” was applied. Fuzzy coding is used to represent traits, characteristics, or variables that are not strictly categorical or binary. Fuzzy coding allows for a more nuanced approach by assigning partial membership of a species or taxa to multiple categories per trait, reflecting the degree to which a trait belongs to the different possible categories. Fuzzy coding scores range from 0 to 1, 0 being no affinity to a particular category, and 1 being high affinity to a particular category. Columns A-D indicates the taxonomic categories of eighty benthic epifauna (the invertebrates living on, protruding from, anchored in, or attached to benthic substrata). Columns E-AQ (row 1) represent nine traits (average captured biomass, maximum adult size, body form, adult longevity, larval development type, adult mobility, living habitat, feeding mode, attachment), which is further divided into 39 modalities in columns E-AQ (row 2). These modalities are represented by codes in E-AQ (row 3). Modalities range from three to six per trait, and scores range from 0 to 1. The nine traits, encompassing morphology, life history, and behaviour, were characterised by 3 to 6 modalities each. To build the database, trait data were sourced from a wide range of literature and resources, including the World Registry of Marine Species (WoRMS), Biological Traits Information Catalogue (BIOTIC), SeaLifeBase, the Arctic Traits Database, scientific publications, field guides, books, theses, and expert knowledge. Specific traits such as body form and body size were directly observed and measured. Certain trait information (e.g. body form and body size) was obtained and recorded directly through physical observations and measurements.