Extensive gaps and biases in our knowledge of a well‐known fauna: implications for integrating biological traits into macroecology

Abstract

Aim Ecologists seeking to describe patterns at ever larger scales require compilations of data on the global abundance and distribution of species. Comparable compilations of biological data are needed to elucidate the mechanisms behind these patterns, but have received far less attention. We assess the availability of biological data across an entire assemblage: the well‐documented demersal marine fauna of the United Kingdom. We also test whether data availability for a species depends on its taxonomic group, maximum body size, the number of times it has been recorded in a global biogeographic database, or its commercial and conservation importance. Location Seas of the United Kingdom. Methods We defined a demersal marine fauna of 973 species from 15 phyla and 40 classes using five extensive surveys around the British Isles. We then quantified the availability of data on eight key biological traits (termed biological knowledge) for each species from online databases. Relationships between biological knowledge and our predictors were tested with generalized linear models. Results Full data on eight fundamental biological traits exist for only 9% (n= 88) of the UK demersal marine fauna, and 20% of species completely lack data. Clear trends in our knowledge exist: fish (median biological knowledge score = six traits) are much better known than invertebrates (one trait). Biological knowledge increases with biogeographic knowledge and (to a lesser extent) with body size, and is greater in species that are commercially exploited or of conservation concern. Main conclusions Our analysis reveals deep ignorance of the basic biology of a well‐studied fauna, highlighting the need for far greater efforts to compile biological trait data. Clear biases in our knowledge, relating to how well sampled or ‘important’ species are suggests that caution is required in extrapolating small subsets of biologically well‐known species to ecosystem‐level studies.

Resistance of polychaete species and trait patterns to simulated species loss in coastal lagoons

“…Knowledge on the biological traits of species is incomplete for most marine invertebrates (Tyler et al, 2011), so even after the exhaustive literature search information was missing for several traits in some species. In these cases (15.5% of the data), information was stepwise first deduced from congeneric species; then from confamiliar species.…”

“…Furthermore, only the polychaetes fraction of the macrobenthos dataset was analysed. Since the main aim of the study was to investigate general relationships between the different aspects of the ecosystem, focusing on a rather well-studied taxon with plenty of available expertise to collect traits information minimises the bias due to gaps in information -a common problem in biological traits analysis (Tyler et al, 2011) and allows a better estimate of the reliability of the method. This study therefore presents a simplified approach to potential real-world changes.…”

ECo: A new measure evaluating the degree of consistency between environmental factors and spatial arrangement of species assemblages

“…Although the biogeographic accuracy of OBIS data has been previously questioned (Mora et al, 2008;Robertson, 2008), OBIS database has grown from around 15 million records in 2008 (the year it was heavily criticized, see Mora et al, 2008;Robertson, 2008), to almost 33 million records in 2012 (Vanden-Berghe, 2012). This has recently promoted its use in several macroecological studies Tittensor et al, 2010;Webb et al, 2010;Tyler et al, 2012). However, to minimize potential bias related to unequal sampling, we selected the 50 fish families with the highest number of known point records.…”

Species that share traits do not necessarily form distinct and universally applicable functional effect groups

“…This is because levels of ecosystem process and functioning are a product of multiple variables , which also means that the extent and importance of biological mediation can inadvertently be misrepresented when only a subset is considered ). This position is unlikely to change in the short to medium term, as extensive gaps in knowledge of basic trait data (Tyler et al 2012), the phenomenological status of models describing species−environment interactions (Snelgrove & Butman, 1994) and the lack of critical assessment of assumed species roles are unlikely to be resolved rapidly.…”