Abstract
Freshwater ecosystems rank among the most endangered ecosystems in the world and are under increasing threat from aquatic invasive species (AIS). Understanding the range expansion of AIS is key for mitigating their impacts. Most approaches rely on Species Distribution Models (SDMs) to predict the expansion of AIS, using mainly environmental variables, yet ignore the role of human activities in favouring the introduction and range expansion of AIS. In this study, we use five SDM algorithms (independently and in ensemble) and two accuracy measures (TSS, AUC), combined with a null modelling approach, to assess the predictive performance of the models and to quantify which predictors (environmental and anthropogenic from the native and introduced regions) best explain the distribution of nine freshwater invasive species (including fish, arthropods, molluscs, amphibians and reptiles) in a large island (Great Britain), and which species characteristics affect model performance. Our results show that the distribution of invasive species is difficult to predict by SDMs, even in cases when TSS and AUC model accuracy values are high. Our study strongly advocates the use of null models for testing SDMs performance and the inclusion of information from the native area and a variety of both human-related and environmental predictors for a more accurate modelling of the range expansion of AIS. Otherwise, models that only include climatic variables, or rely only on standard accuracy measures or a single algorithm, might result in mismanagement of AIS.
Highlights
Developing a scientific basis for monitoring and managing invasive species and implementing measures to manage pathways to prevent introductions is one of the CBD Aichi Targets for 2020 [1]
We have shown that both environmental and anthropic variables should be included in models that aim to understand and predict the distribution of aquatic invasive species
Our results highlight the fact that different species may require different sets of predictors and that the inclusion of information about conditions in the species’ native area may be required to model their distribution accurately, making it difficult to generalize across taxa
Summary
Developing a scientific basis for monitoring and managing invasive species and implementing measures to manage pathways to prevent introductions is one of the CBD Aichi Targets for 2020 [1]. Freshwater invasions are of special concern, as freshwater ecosystems are among the most diverse and endangered ecosystems in the world [2], harbouring more than a quarter of all freshwater fauna threatened or recently extinct [3], in part due to the impact of non-native freshwater species on native biodiversity [4]. Despite an increase in the number of studies focusing on freshwater invasions in recent years [5], the main drivers of the introduction and spread of aquatic invasive species (AIS) are still unknown [6]. Improving Species Distribution Models of freshwater invaders
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
