Eight years of BioInvasions Records: patterns and trends in alien and cryptogenic species records

Abstract

“ BioInvasions Records ” (BIR) is an international journal founded in 2011, with its primary focus the publication of new records of non-native species. We analyzed all published articles in BIR between 2012 and 2019, aiming to: make all georeferenced records openly available; investigate spatio-temporal patterns in reported records, methodologies for species identification, and pathways of invasion; and identify possible biases in reporting alien species occurrences and distributions. In total, 10457 georeferenced records were retrieved from 467 published articles, reporting 628 different species. Terrestrial species were under-represented in the dataset. Chordata dominated in the list of reported species, followed by Arthropoda, Mollusca, and Tracheophyta. Europe was the continent with most recorded species, followed by North America. In terms of species reported by country, USA ranked on top. This geographic bias is in accordance with global patterns of research output, related to the fact that North America and Western Europe are leaders in funding research and development, and this is where the majority of highly ranked universities are situated. The country diversity of reported species exhibited an increasing trend from 28 countries in 2012 to 49 countries in 2019. Single-author papers represented only ~ 5% of all published papers, and the median number of authors has increased from 3 in 2012–2013, to 4 in 2015–2019, following global trends of increased collaborations. The frequency of conducting molecular analyses for species identification has increased from 4.5% of published articles in 2012 to 25.2% in 2019, and is expected to further increase with the continuing development of molecular tools, in particular rapid advances and cost reduction in eDNA, next-generation sequencing, barcoding and metabarcoding analyses. The most common pathway of introduction (based on the CBD classification) was “transport-stowaway”, followed by “escape from confinement” and “corridor”. However, the importance of pathways significantly differed by environment. “Transport-stowaway” was the most important pathway for marine and transitional species, whereas “escape from confinement” was the most important pathway for terrestrial and freshwater species. The most important CBD pathway subcategory was “ship/boat ballast water”, followed by “interconnected waterways/basins/seas”, “natural dispersal across borders”, “ship/boat hull fouling”, “aquaculture/mariculture”, and “pet/aquarium/terrarium species (including live food for such species)”. BIR has provided the means for publishing valuable information on the distribution of alien species, the dynamics of invasions, and pathways of introduction, therefore substantially supporting invasion science and management.